Subject NOT available

Nanae ofthi Fertilizer

Specifications

(iii) Ammoniacal nitrogen percent by weight minimum 9.0

(iv) NiUtral ammonium citrate soluble phosphates (as

P, O,) per cent by weight minimum 28.0

(v) Water soluble phosphates (as P,O,1 per cent bv

weight minimum.

' 25..

(vi) Particle size All the material shall pass through 3 .35 mm IS sieve and 90 per cent will be retained on 1.18 mm IS sieve.

32. Fus=d Calcium Mag- (i) Moifturc per cent by weight maximum. . 5 0 nesium Phosphate.

(ii) Phosphate fas Pi O,) soluble in two per cent citric

acid solution, per cent by weight minimum. . , 15

(iii) Fineness

(a) Retained on 150 micron IS sieve, per cent by weight Nil

(b) Passing 100 micron IS sieve, per cent by weight minimum.

80

2 1. R ock Phosphate.

(i) Particle iize The material shall completely past through 6.3 mm IS sieve and not less than 20 per cent of material shall pass through 150 micron IS sieve.

(ii) Total P, O, content to be guarentced Vy the

dealer.

B. Tolerance limit in plant nutrient for various ftrtiliMeri

1. *>"!":• liz?r" with difliito compounds like ammonium sulphate, urea, i n n i " i um chloride, muriate of potash, sulphate of potash, super- phosphate, dicilcium phosphate, which contain more than 20 per cent plant nutrients.

—0.2

F)r those which contain less than 20 per cent plant nutrients . —o.r

2. For calcium ammonium nitrate —0.3

1. For diamnonium phosphate, nitrophosphates, ammonium i 1¹ 1 hit^ nitrate, urea ammonium phosphate, ammonium phosphate sul- j" i'" e, boic m*il, gun'jlated mix:d fertilizers, compound fertilisers. . —0.5 for indivi- dual putrients subject to the maximum —2.5 per cent for all combined nutrients.

(9) After S;h;1i1e I to this O:dsr,ths following schedule shallbe inserted namely:—

SCHEDULE II

(Set clause 14A)

A. Proztdwe for Drawing Samples of Fertilisers

I. Oe wral requirements of sampling

In drawing ja*nples the following measures and precautions shallbe observed :

(a) Sa-nplea ihall notbetaken at a place exposed to weather. (b) Tho sampling instruments shall be clean and dry when used. (Diagram of the sampl.

tube given separately).

(c) The material being sampled, the sampling instruments and the containers for sam- ples shall be protected from adventitious contaminations.

(d) To draw a representative sample, the contents of each container selected for sampling shall be mixed as thoroughly as possible by suitable means.

(e) The samples shall be placed in suitable, clean, dry and air-tight glass or other suitable containers.

(f) The sample containers shall be of such a size that they are almost completely filled by the sample.

(g) Each sample container shall be sealed air tight after filling, and marked with ful datails of sampling, the date of sampling and other important particulars of the coiv signment.

(h) Samples shall be stored in shade.

2. Sampling from packages or containers.

(a) Seals of sampling

(i) Lot—All containers in a single consignment of the material of the same grade and type, drawn from a single batch of manufacture shall constitute a lot. If a con- signment 19 declared to consist of different batches of manufacture, the batches shall be marked separately and the group of containers in each batch shall constitute^ separate lots. In the case of % consignment drawn from a continuous process, ijOoo containers (or 100 tonnes ) of the material shall constitute a lot.

(ii) The number of containers to be chosen from a lot shall depend on the size of the;

lot and shall be as given in Table below :—

Number of Containers (packages to be selected for Sampling

Lot Size

Number of containers to be selected

n

N

(2)

CD

2

2 —8

3 4

9—27 28—64 65—100

5 6

7 8

9 10

IOI—30° 301—500 501—800 801—1300 1301 and above

These containers shall be chosen at random from the lot, and in order to ensure random- ness of selections a random number table as agreed to between the purchaser and the supplier shallbeuscd. Incase such a table is not available, the following proceduremay be adopted:

Arrange all the containers in the lot in a systematic manner and starting from any container, count them as 1, 2, 3. up to r and so on, r beThg equal to the integral part of iV/ra. Every rth container thus counted shall be with drawn and all such containers shall constitute the sample.

(b) Preparation of composite samples

(i) Draw, widi an appropriate sample iastrument, small portions of the material from different parts of each container in the gross sample. The portions so obtained from the containers shall be mixed thoroughly and made into a composite sarrple-

(ii) If the containers do not permit the use of sampling instrument, empty the con- tents of the containers on a level, clean, hard surface and draw a composite sample by the process of quartering as described under 2(0) (iii) below.

(iii) If the composite sample is much larger than about 4 lb. (2 kg.) in weight, Its size shall be reduced by the method of quartering. Spread the composite sample on alevel, clean, hard surface, flatten it out and divide it into four equal parts. Remove any diagonally opposite parts.

Mix the two remaining parts together to form a cone, flatten out the cone and re- peat the operation of quartering till a composite sample of about 4 lb. (2 kg.) in weight is obtained.

3. Sampling from bulk in heaps or zaagons

(a) Scale of sampling

Samples shall be taken from each heap or wagon as the case may be.

(b) Preparation of composite samples

Draw several samples (at leaBt 10) from each heap or wagon by means of a scoop frcm different parts, vie., the front middle and back and at different depths so that the sample taken is representative of the bulk. Mix thoroughly the samples so coll lected on a clean, hard surface and draw a composite sample by the process of, quartering as described under 2 (b) (lii) above.

4. Test saviples and reference sample

(a) Preparation of test samples

(i) The composite samples obtained under parus 2 or 3 abovo shall be spread out on a clean, hard surface and divided into three more or less equal portions not less than 1 lb. (0.5 kg.) each. Each of these samples shall constitute the test sample.

(ii) Each test sample shall be immediately transferred to a suitable container, as des- cribed under i(e) and i(f), provided with a tight fitting Btopper or lid so that the original composition of the fertiliser remains unchanged. Each container shall be properly labelled giving all the particulers of the consignment as des- cribed under 1 (g).

(iii) Each test sample container shall then be sealed with seals of both the Ins- pecting Officer and the manufacturer or dealer or purchaser as the case may

(iv) One sample so sealed shall be sent to the State Fertilizer Analyst or analysis and the second given to the manufacturer or dealer or purchaser as thecase may be. The third sample shall constitute the reference sample and shall be retained by the Inspecting Officer for production In the.Court, if necessary.

B. Mithods of Analysis of Fertilizers

1. Preparation of sample for analysis in tht laboratory

1. 1 Procedure

1. Reduce gross sample to quantity sufficient for analysis Or grind not <0-5 lb. of reduced uafnple without previous sieving.

2. For fertiliser mitcrials a"U en Jlst fertiliser mixtures)that form a paste onputting pressure, gciii 1 in 1 Jrcelain p^tle aid iHO;tarto pus sieve with 1 rnTi circular ^openings or No, 20 standard sieve.

3. For dry mixtures that t e ll to jjjrcgate, grind in a porcelain pestle 7 and mortar to pass No, 40 standard aicve.

4. Grind as rapidly as possible to avoid loss or gain of moisture during operation.

5. Mix thoroughly and store in tightly stoppered bottles.

2, Determination of moisture

(Not applicable to sanples thit yield volatile substances other than, water at drying tem- perature).

2.1 Procedure

1. Weigh to the nearest mg a'oout 2 g.n of the prepared sample in a weighed, clean, dry squat form weighing bottle.

2, Heat in an oven for about 5 hours at 99—IOI°C to constant weight. Cool in adesi- CBtor and weigh.

Reagents

1. Ioiinc solution—Add 125 g n of iodine to a mixture of 6^0 ml. of methanol andj2oo ml.

of pyridine contained in a flask, and immediately close the flask tightly.

2. Silphur dioxide solution—?ass dry sulphur dioxide into 100 ml. of pyridine 'contained in a25O ml- graduated cylinder and cooled in an ice bath, until the volume reaches 200 ml.

3. Fischer Reigent—Slowly add iodine solution to the cooled sulphur dioxide solution stopper immediately and shake well until the iodine is dissolved. Transfer the solution to an automatic pipette, protected from absorption of moisture by a drying agent and allow to stand for 24 hours before standardising. The reagent deteriorates continuously and it should be standar- dized within one hour before use.

3. In CBSC of sodium, nitrate, ammonium sulphate and potassium salts heat to constant weight at 129—i3l°C.

4. Report percentage loss in weight as moisture at temperature used.

Calculations

TOOXB-C Free moisture percept

hy weight = - g - ^—

A = Weight of the bottle.

B =• Weight of the bottle plus material oeror drying.

C ™ Weight of the bottle plus material alter drying.

(Refcrercc'Methods of Analysis", AOAC. 1965;

2.2 Moisture in Ammonium CUoride

1. Weigh accurately about 5 gin. of prepared sample in a weighed shallow porcclaia dish and dry for 24 hours in a vacuum desicator over sulphuric acid ana re-weigh.

2. preserve the dried material for subsequent tests.

Calculations

Wi Moisture percent by weight = 100 :< _

W3

Wi — loss in weight in gm. on drying, ard

W3 = weight in gm. of the prepared sample taken for the test.

2.3 Samples like urea, diammonium phosphate and amrnpnium nitrate which yield volatile substances other than water at drying temperature, the Karl Fischer method given below is used for the determination of moisture.

4. Standard water solution—Measure exactly 2 ml. of water into a thoroughly dry 1 litre volumetric flask, dilute to volume with methanol. Retain sufficient quantity of the sanie methanol for a blank determination. Keep the solution in tightly closed containers.

Procedure

1. Determination of End point in Karl Fischer Titration—In many cases, the end point can be detected visually by the change of colour from a light brownish yellow to amber. But when the end point is not clearly defined, the electron-]etric method for determining the end point should be adopted. Adjust the potentiometer so that when a small excess (o 02 ml.) of the reagent is present, a current of 50 to 150 microampers is recorded. The solution should be continuously and vigorously stirred. At the beginning of the titration, a current of only a few microftmpcrs will flow. After each addition of reagent, the pointer of the micrometer is de- flected but rapidly returns to the original position. At the end point a deflection is obtained which endures for a longer period.

2. Standardization of the Fischer reagent—Pipette exactly 10 ml. of methanol into a dry titration flask and titrate with the Fischer reagent to the end point.^Thc pipette exactly 10 ml of the standard water solu'i ':i into the flask and titrate to the end point.

3. Titration of the material—Transfer 25 ml. of methanol to the titration flask and titrate to the end point with the Fischer reagent. Do not record the volume consumed. Quickly trans- fer to the titrated liquid an accurately weighed quantity of the material containing 10 to 50 mg. of water, stir vigorously and titrate to the end point.

Calculation

o.iyWCV,—2.5VJ

Moisture percent by weight = -- , y ~ y ~^

where

W~> weight in mg of water contained in 10 ml. of standard water solution V,=total volume in ml, of the reagent used in titration in (3). V ,-= volume in ml of reagent used in titration of mcthajiol in (2) and Vj^totil volume in ml. f f the reagent used in titrationi n (ii) A—weight in gm of the material taken for the test in (3) (Reference I.S. Specification for urea, technical and pure, I.S. 1781—1961I

3. Determination of nitrogen.

Methods of determination of total nitrogen, ammoniacal nitrogen, nitrate nitrogen, and -urea nitrogen have been described separately in this section. These methods can be adopted both for straight and mixed fertilisers. Scope of each method with various combinations have also been described with each method.

The relevant methods of analysis which have been described are as given below :

I. Total Nitrogen—for nitrate free samples.

a. Total Nitrogen—for nitrate containing samples.

3. Total nitro^-n—for materials with high cl:NO, ratio and to materials containing only water-soluble nitrogen.

4. Determination of ammoniacal nitrogen.

5. Determination of amrnoniacal and nitrate nitrogen.

6. Determination of nitrate nitrogen. 7. Determination of water insoluble nitrogen. 8. Determination of urea nitrogen. 3.1 Detection of nitrate d

For adopting a specific method as describ-d above, it is necessary to detect the presence of nitrates in the sample before a particular me.hod is adopted, The procedure for detection of nitrates is given below.

1. Mix 5 gm sample with 25 ml. hot water and filter.

2. To one volume of this solution add 2 volume of sulphuric acid, free from HNO3 and oxides of N, and let it cool.

3. Add a few drops of concentrated Fe SO< solution in such a manner that flu ids do not mix.

4. If the nitrates are present junction shows at first purple, afterward brown, or if only minute quantity is present, reddish colour.

5. To another portion of solution add 1 ml. 1 per cent Na NO8 and test as before to de- termine whether enough Ha SOj was added in the first test.

(Reference "Methods of Analysis" AOAC, 1965)

3.2 Reagents for determination of total nitrogen

(i) Sulphuric acid— 93-98 percent He SOt, N free.

(ii) Copper sulphate — Cu SO<. 5. H, O reagent grade, N free.

(iii) Potassium sulphate (or anhydrous sodium sulphate)—reagent grade.

(iv) Salicylic acid—reagent grade, N free.

(v) Sulphide or thiosulphate solution—Dissolve 40 gm. commercial K, S in 1 litre dis- tilled water.

(Solution—of 40 gm. Na, S or 80 gm Na2 S, OB. ; H, O in 1 litre may be used).

(vi) Sodium hydroxide—Pellets or solution, nitrate free. For solution dissolve appro- ximately 450 gm solid NaOH in disullcd water and dilute to 1 litre (Sp. gr. of solution should be j.36 or higher).

(vii) Zinc granule—reagent grade.

(viii) Zinc dust—Impalpable powder,

(ix) Methyl red indicator—Dissolve 1 gm. methyl red in 200 ml. alcohol.

(x) Hydrochloric or sulphuric acid standard solution, 0.5N or o. iN when amount of N is small.

(xi) Sodium hydroxide standard solution—0.1 N (or other specified concentration ).

1. Standardize each standard solution with primary standard and check one against another.

2. Test reagents before using, by blank determination with 2 gm. sugar which insures partial reduction of any nitrates present.

Caution : Us- freshly opened sulphuric acid or add dry P, O, to avoid hydrolysis of nitriles and Cyanates. Ratio of salt to acid (wt. Vol) should be approximately 1 : 1 at end of digestion for proper temperature control. Digestion may be incomplete at lower ratio, N may be lost at higher ratio.

3.3 Apparatus

(a) For digestion— Use Kjeldahl flask of hard moderately thick, well annealed glass with total capacity approximately 500-800 ml. Conduct digestion over heating device, adjusted to bring 250 ml. water at 25⁰ C to rolling boil in approximately for 5 minutes. Add 3-4 boiling chips to prevent superheating.

(b) For distillation—Use Kjeldahl or other suitable flask of 500-800 ml. capacity filled with rubber stopper through which passes lower end of efficient scrubber bulb or trap to prevent mechanical carryover of NaOH during distillation. Connect upper end of bulb tube to condenser tube by rubber tubing. Trap outlet of condenser in'such a way as to insure complete absorption of ammonia distilled over into acid in receiver.

3.4 Total nitrogen (in nitrate free samples)

Procedure

1. Place weighed sample (0.7-2.2 gm.) in digestion flask.

2. Add 0.7 gm. coppcr'sulphate, 15 gm. powdered Ka SOt or anhydrous NatSO4, and 25 ml. H, SO,.

3. If sample more than 2.2 gm. is used, increase sulphuric acid by 10 ml. for each gm. sample.

4. Place flask in inclined position and heat gently until frothing ceases (if necessary add:

small amount of paraffin to reduce frothing).

5. Boil briskly until solution clears tJid then for at least 3o minutes longer (z faourft- for samp c containing organic material).

6. Cool add approximately 200 ml. distilled water, [cool below 25°C.

7. Add to the flask a layer of sodium hydroxide (25 gm solid reagent or enough solution to make contents strongly alkaline) without agitation.

8. Immediately connect flask to distilling bulb or condenser and with tip of condense immerse in standard acid in receiver.

9. Rotate flask to mix contents thoroughly, then heat until all amonia has distilled (at least 150 ml distillate).

10. Titrate excess standard acid in distillate with standard sodium hydroxide solution, using methyl red as an indicator.

11. Correct for blank determination on reagents.

Calculation

T, ,T. (AN"—BNt)x 0.01401x100 Percent Nitrogen — - ^

A —ml. of standard acid used.

B—ml. of standard NaOH used.

N" —Normality of standard acid.

Nb —Normality of standard NaOH.

W"^Weight of the sample taken in grams.

(Reference "Methods of Analysis", A.O.A.C. 1965).

j . 5. Total Nitrogen (for nitrate containing samples)

(Not applicable to samples containing high concentrations of nitrate nitrogen and chlorides)

Procedure

1. Place weighed sample (0.7—2.2 gm) in digestion flask.

2. Add 40 nil. H,SOt containing 2 gramj salicylic acid, ^hake until thoroughly mixed and let stand, with occasional shaking, 30 minutes or more.

3. Then add (1) 5 grams NasS,O,. 5HtO or (if) 2 grams zinc dust (as unpalpable powder not granulated zinc or filings).

4. Shake the flask and let it stand for five minutes, then heat over low flame until forthing ceases.

5. Turn off heat, add 0.7 grms copper sulphate, 15 gm. powdered K,SO4 (or anhydrous Na2SO"), and boil briskly until solution clears, then at leaBt 30 minutes longer (? hours- for samples containing organic material).

Proceed further as in 6-11 of 3.4.

Calculations

Same as in 3.4.

(Reference "Methods ot Analysis"—A.O.A.C, 1965).

3.6. Total nitrogen (for materials with high Cl: NO, ratio and to materkls containing otify mater-'

soluble mtrogen).

Reagents

Reduced iron powder, electrically reduced, N.F. (National Formulary). For other reagents.

"ee3-2-

Procedure

Mixed Fertilisers

1. Place 0,5—2.0 gm sample in Kjeldahl flask and add 2-5 grama, reduced Fe (5 gms. !*> enough for 0.185 grmB. NO,).

2. Add approximately 25 ml. distilled water, rotating flask at angle to wash down the sample.

3. Let it stand for 15 minutes with occasional agitation, to insure complete solution of all soluble salts.

4. While rotating flask add 25 ml. cold H,SO, (1 + 1) and let it stand until visible reaction ceases. (Use hood or vented digestion unit),

5. Add boiling chips and boil 15—20 minutes, but do not take to dryncss. (For samples containing organic matter, use 50 ml. cold H,SO4 (1 + 1), boil for 15—20 minutes, add 0.7 gm. HgO and heat again for 30 minutes). Cool and proceed further as in 6—n of 3.4.

Calculations

Same as in 3.4

(Reference "Methods of Analysis", A.O.A.C., 1965).

J . 7. Determination of ammoniacal nitrogen {Distillation Method.)

(This mrthod is for the determination of nitrogen present or available in the sample as ammonium ion. This method assumes that Urea is absent from the sample. No applicable to MgNH4 PO4 and Fe Nt^PO*)

Procedure

1. Place 0.7—3.5. grms; according to NH3 content of the sample, in distillation flask with approximately 300 ml. water and 3 grins, of freshly ignited carbonate free MgO or NaOH solution.

2. Connect the flask to condenser by Kjcldahl connecting bulb.

3. Distill ico ml. liquid into measured quantity of standard add and titrate with standard NaOH solution, using methyl red as an indicator.

Calculations

(ANa—BNtOxo.01401 x 100

Percent Nitrogen =

W

A-ml. of standard acid used. B-ml. of standard N"OH. Ni-normality of acid. Nb-normaUty of NaOH W-weight of the sample taken in gms.

(Reference (Recommended analytical methods of the National Plant pooj Institute, Washington, D. C, I ^ I )-

•3,8. Determination of ammoniacal and nitrate nitrogen

D&>arda Metliod

(This method is for the determination of total nitrogen when only nitrate or mixture of nitrate and ammoniacal nitrogen is present. This method assumes the absence of Urea, Calcium Cyanamide Cyanamide and organic matter from the sample).

Procedure

1. Place 0.35—0.5 gma. sample in 600—700 ml. flask and add 300 ml. water, 3 grma. Dsvarda alloy, and 5 ml. NaOH solution (42 percent by weight pouring later down side of flask so that it does not mix at once with contents).

2. Allow the flask to stand for 15 minutes. 3. By means of Davison (J Ind Eng. Chcm.n, 465. (1919)) or other suitable scrubbing bulb that will prevent passing over of any spray connect with condenser, tip of which always extends beneath surface of standard acid in receiving flask.

4. Mix contents of distilling flask by rotating. 5. Heat slowly at first, and then at a rate to yield 250 ml. distillate in 1 hour.

6. Collect distillate in measured quantity of standard add and titrate with standard NaOH •ohition, using methyl red as an indicator.

7. In analysis of nitrate salts dissolve 3-5 or 5-0 gnns. in water, to 250 ml and use 25 m 1 aliquot.

Calculations

Same as in 3-4

(Reference "Methods of Analysis", AOAC)

3 • 9 Determination of nitrate nitrogen

(Applicable in presence of caldum cyanamide and urea in the mixture).

Procedure

(a) Determine total nitrogen as in 3-5.

(b) Determine water insoluble N as in 3'10 but use 2-5 grms. sample. Dilute to 250 ml.

(c) Determine amoniacal N in 50 ml filtrate as in 8 • 7

(d) Place another 50 ml portion filtrate in 500 ml Kjcldah flask and 2 grins. Fe SO*¹' 7H10 and 20 ml H, SO4. (If total N is 5 percent use 5 gm Fe SO4 7 H2 O). Digest over hot flame until all water is evaporated and white fumes appear and continue digestion at least ten minutes to drive off .Nitrate N. If severe bumping occurs, add 1CM5 glass beads. Add 0-65 grms. Hg or 0-7 grros HgO and digest until all organic matter is oxidized cool, dilute add the K,S solution and complete determination as 3-4. Before distillation add pinch of mixture of Zinc dust and granular "20 mesh". Zinc to each flask to prevent bumping.

Calculations

Total N (a)—water insoluble N (b)—water soluble N.

Water sol N—N obtained in (d) "• Nitrate N.

(Reference Methods of Analysis A.O.A.C, 1965).

3.10 Determination of water insoluble nitrogen

Procedure

1. Pake 1 or 1-4 grms. sample in 50 ml. breaker, wet with alcohol.

2. Add 20 ml . water and let it stand for 15 minutes, stirring occasionally.

3. Transfer supernatant liquid to 11 cm. Watman No. 42 paper inJ6o° long stem funnel 3" 5* diameter and wash residue 4 or 5 times by decanting with water at room temperature (ao-25⁰ C).

4. Finally transfer all residue to filter and J complete ^ washing until filtrate measures 350 ml.

5. Determine N as in 3-A.

3-11 Determination of Urea nitrogen

(ThiB method is for the determination of urea content of any mixed fertilizer)

Reagents

1. Neutral urease solution—shake I gm jack bean meal with TCO ml. water for 5 minute;, Tranfer 10 ml. solution to 250 ml, erkmncyer flask, dilute with 50 ml. water and adt 4 drops methyl purple indicator. Titrate with O. 1 N HCI to reddish purple, then back titrati to green with O. I N NaOH. Frcm difference in ml., calculate amount of O. 1 N HCi requirei to neutralize remainder of solution (usually approximately i- 5 ml. per ICO ml) add this smcuntj) •f acid and shake well.

Procedure

1. Weight io+o-oi gin. sample and transfer to 15 cm. whatman No, 12 fluted filter papar.

2. Leach with approximately 300 raL water into 500 ml volumetric flask.

3. Add 75-100 mL saturated barium hydroxide solution to precipitate phosphates.

4. Let it settle and test for complete precipitation with few drops, of saturated barium hydroxide solution.

5. Add 20 ml. 10 per cent sodium carbonate solution to precipitate excess barium and any soluble calcium salts.

6. Let it settle and test for complete precipitation.

7. Dilute to volume, mix and filter through 15 cm. whatman No. 12 fluted paper.

8. Transfer 50 ml aliquot (equivalent to 1 gm, sample) to 200 or 250 ml, erlcnmcyer flask and add I to 2 drops methyl 1 purple indicator.

9. Acidify solution with 2NHCI and add 2 to 3 drops excess.

10. Neutralize solution with 1 O. 1 N NaOH to first change in colour indicator.

11. Add 20 ml neutral urcaac solution, close flask with rubber stopper and let it stand fof X hour at 2O-25°C.

12. Cool tho flask in ice water slyurry and titrate at once with O.i Ncl to full purple fl lour, then add approximately 5 ml, excess.

13. Record total volume added, back titrate excess HC1 with O.I N NaOH to neutral end JJJint.

Calculations

Percentage urea—(ml O.i N HC1—ml O. 1 N NaOH) x 0 • 3003/wt. of the sample.

(Reference "Methods of Analysis" A. O. A. C, 1965).

3-12 Determination of biurtt

Reagents

1. Alkaline tirtarate solution—Dissolve 40 gm, Na OH in 50 ml. water cool, add 50 gm of NiK CtHtOS-4H,O and dilute to 1 litre. Let it stand for o.ie day bsf ore use.

2. Copper sulphate solution-Dissolve 15 gm CUSO4. 5H1O in CO, free water and dilute to i l i a c.

3. Biuretstandardsolutloii—1 mg/ml. Dissolve 100 msreagent grade biuret in COt free water and. dilute to 100 ml.

4. Ion exchange resin. Fill 50 ml. burette with 30 cm column of Amberlite IR 120 (H) resin Jnglass wool plug. Regenerate column after each use by passing 100 ml H4SOi (1+9) or I;l(i+4) through the column approximately 5 ml. per minute and then washing with water autilpH of effluent ia 76.

preparation of standard curvt

1. Transferseriesofaliq'-iots,2-5Oml.ofstandard biuretsolutiontoiooml. volumericflask.

2. Adiust volume to approximately 50 ml with COi free water . Add one drop of methyl red and noutrelize with O.IN H, SO* to pink colour.

3. Add with swirling 20 ml, alkaline tartarate solution and then 20 ml CuSOi solution.

4. Diluteto volume. Shake for 10 seconds and place in water bath for 15 minutes at 30 ± . 5 0 ^.

5. Also prepare reagent blank,

6. Determine absorbance of each solution aqainat blank at 555 mw (Instrument with 5oo-57omvv filter is also satisfactory) with 2-4 cm. cell, and plot standard curve,

Procedure

In uni

1. Stir continuously 2-5 gm sample in 100 ml approximately 50* C water for 30 minute*.

2. Filter and wash into 250 ml volumetric flask and dilute to volume.

3. Transfer 25 ml aliquot to 100 ml volumatric flask and proceed as given under preparation, -of standard curve 3" 12.

In mixed ftrtfliseri

1. Stir continuously 10-20 gm sample in 150 ml approximately (50° C) hot water for 30 minutes.

2. Filter and wash into 250 ml volumetric flask and dilute to volume.

3. transfer 25 ml aliquot to column 3-12 (4) and adiust flow to 4-5 ral/minute.

4. Receive eluate in 100 ml beaker.

5. When liquid level falls to top of resin bad, wash with two isJml portion water.

6- To eluate and washings add two drops of methyl red and then IN NiOH to ydlosr ":61our.

7. Add 0*1 N,SO4 until solution just turns pink.

8. Transfer to 100 ml. volumetric flask and dilute to volume with COt free water.

0. Transfer 50 ml aliquot to 100 ml volumetric flask and proceed as in preparation of •standard curve given above.

Calculations

From standard curve determine concentration of biuret in final dilution, then per cent of ,. Cxioo biuret .= -^

where C ^Concentration in m?/ml of biuret in fiial dilution obtained from standard curve W™Conccntration of original sample in final dilution expressed as mg/ml.

(Reference "Methods of Analysis" A, O. A. C.)

3.11 Determination of fret acidity in ammdniun sulphate (asHtSOJ

OReaFents

1. Standard sodium hydroxide solution—0-02 N

2. Methyl red indicator^Dissolve o-15 gen of water soluble melthyl red in 500 ml water.

3. Methyl red^Methyl blue mixed indicator solution—prepared by mixing equal volumes *>f 0- 2 per cent solution in rectified spirit of methyl red and o-1 per cent solution in rectified spirit of rnethyienc blue,

{Procedure

1. Dissolve about 20 gm of prepared sample accurately weighed in about 50 ml. cold natura UrttBr.

2. Filter and make up the volume to about 200 ml.

3. Titrate with standard sodium hydroxide solution, using one or two drops] of methylred iM indicator.

4. If satisfactory end point with methyl red is not obtained, methylene red—•methyleno &>ltie mixed indicator may be used.

5. Use preferably a micro biuiet for this titratian.

*The filtering medium shall be neutral and shall not contain any alkaline material which would neutralize free add.

Calculations

4^904 AN Free acidity as H, S0" per cent by weight "• —

T

A—Volume of ml of standard NaOH solution.

N—Normality of standard Na OH solution.

W—Weight in gm of prepared sample taken for the test.

(Reference—Specifications for ammonium sulphate, fertilizer grade 18:826-1967)

3 • 14 Determination of Arsenic in Ammonium sulphate (as At O,).

Rtagtnts 1. Lead acetate solution—Prepare 10 per cent solution of lead acetate with sufficient acetic add added to dear the solution.

2. Dry lead acetate paper—Cut filter paper (Whatman No. I or equivalent) into strips 70M50 mm and keep them permanently suspended in lead acetate solution in a glass stoppered bottle. Before use, take out the strips and dry them in an atmosphere free from hydrogen sulphide.

3. Mercuric Bromide solution—Dissolve 5 gm of mercuric bromide in too ml rectified spirit.

t Sinsittaed Mercuric Bromide paper strips—-cut filter paper (Whatman No. ¹ or equlva" to strips 120x2-5 mm. Keep the strips permanently suspended in dark in a glass stop- pered cylinder or amber bottle having mercuric bromide solution. Before use take out a strip> press it between sheets of filter paper and dry it in an atmosphere free from hydrogen sulphide.

5. Diluto sulphuric acid—approximately 5 N.

6. Concentrated hydrochloric acid.

7. Potassium iodide solution—15 per cent.

8. Stannous chloride solution—Dissolve 80 gm of stanonus chloride in 100 ml. water Containing 5 mi. of concentrated hydrochloric add. If the solution Is turbid add a few ml. of more hydrochloric acid and boil until clear solution is obtained. Add some metalic tin to tho solution to prevent oxidation.

9. Zinc—It is recommended that zinc rods prepared as described below should be used.

For routine work, however, pellets described may be used.

Preparation of zinc rods

1. Take a dean and dry hard glass test tube of 10 mm internal diameter and 20 cm. length 2. Heat the test tube over a flame of Bunsen or blow pipe burner and add slowly arsenic free granulated zinc in small portions (1 to 2 gm at a time) the next portion being added after the first one has completely melted.

3. Continue heating and adding zinc until the melt is about 10 cm high. 4. Heat the clean melt for half an hour and then cool to room temperature. 5. Break the tube to obtain the rod of zinc. 6. Cut rod into pieces 20 mm long.

7. Coat the plane ends of the pieces with a paste of magnesium carbonates and gum arabic solution and dry.

8. Coat the pieces all over with r, 5 mm thick layer of paraffin wax.

9. When required for use, scrap off the wax from the Mane ends with a knife, Drotectjnii wax colour round the rods,

^^

10. Remove the paste from the plane ends by soaking in water and activate the exposed surface by dipping in a solution containing one part of stannous chloride solution and seven parts- of concentrated hydrochloric acid.

Preparation of zinc pellets

Treat zinc shots passing through IS sieve 570 (aperture 5660 microns) and retained on IS> •ieve 280 (aperture 2818 microns) with concentrated hydrochloric acid until the surface of zinc becomes clean and dull. Weigh and keep under waterj preventing contamination with dust. 10. Standard sodium hydroxide solution—approximately 20 per cent.

11. Standard arsenic trioxide solution

I. Dissolve i-o gm of resublimed arsenic trioxide (AS.O,) in 25 ml sodium hydroxide lolution and neutralize with dilute eulphuric acid.

2. Dilute with freshly distilled water containing 10 ml of concentrated sulphuric acid per lhie and make up the volume to 1 litre.

3. Again dilute 10 ml of this solution to 1 litre with water containing sulphuric add and finally dilute 100 ml of this solution to I litre with water containing sulphuric add. One ml of this solution contains o • 001 mg of arsenic trioxide (AS, O,). The dilute solution Bhall be prepared freshly when required.

Procedure

      1.  Dissolve  1 • 0 gm of the prepared sample in 20 ml water.
     2.  Place  dry lead  acetate  paper  in the lower  portion  of the tube  B (in fig.) and  glass  wool
moistened with lead  acetate solution in its proper  portion.
     3.  Place  the sensitized  Btrips of mercuric  bromide  paper  in tube  A  and connect  the tubes-
together  with  a  rubber  stopper.
     4.  Introduce  the solution of the material  into the bottle  C  (120 ml) and then  add 10 ml of
dilute  sulphuric  acid.  Add 0-5 ml of stannouB  chloride solution 5[ml potassium  iodide  sohition^ana
aaake up the volume  with  water to about 50 ml.
      5.  Mix the contents and drop about  10 gm of zinc.  Immediately fit in  position  the  rubber
 •topper  carrying  the  tube  B.
     6.  Place  the bottle in a warm  place  at about  4o°C.
     7.  At the end of two hours  remove the test  strip by means  of tweezers.
     8.  Carry  out the test  prescribed  above  using a volume of standard  arsenic  trioxide  solution,
containing 0 • 1 mg of arsenic trioxide, in place of the  solution of the  material and compare  the stain,
produced with the material with that produced with arsenic trioxide solution.
     9.  The limit  prescribed  in the material  specification  shall  be  taken  as 'not having  beer*,
exceeded  if the  length  of the stain as well as the intensity of  its colour produced in the test  with,
the  material is not greater than those produced with the arsenic solution.

(Reference "Modified Gutzet method of test for arsenic" IS-2088—1962).

3.15 Determination of calcium nitrate (Jor calcium ammonium nitrate and nitrophosphaW),

Reagents 1. n-Amyl Alcohol—

2. Dilute hydrochloric add—approximately 4N.

3. Standard caldum solution—weigh 1.0 gm of calcium carbonate dried at I2O°±5*C and dissolve in the minimum quantity of dilute hydrochloric add. Dilute [The solution to I litre in • graduated flask.

4. Ammonium chloride—ammonium hydroxide buffer solution. Dissolve 67.5 gm ammonium chloride in a mixture of ^70 ml of ammonium hydroxide (sp. gr. 0-92) and 250 ml' w"ter. Also dissolve separately a mixture of 0-931 gm of disodium chthylcne diamlne tetra- aoetatedihydratc and 0-616 gro of magnesium sulphate (Mg SO4. 7H, 0) in about 50 mL of water. Mix the two solutions and dilute to 1 litre.

5. Standard Disodium ethylene diamlne Tetra-acetate (EDTA) solution—weigh 3-72 am °f disodium ethylene diamine tetra-acetate dihydrate in water, and dilute in a graduated flask, *o 1 litre. The solution shall be standardized frequently against standard calcium solution- following the procedure given below.

6. Eriocbrome Black T Indicator solution—Dissolve o.l gm in 20 ml of rectified spirit.

The solution shall be used for not more than a week.

Procedure

1. Grind quickly about 5 gm of the material, accurately weighed, with about 50 ml of amyl alcohol in a pestle and mortar and transfer the contents to a conical flask.

2. Wash the pestle and mortar with a few ml of amyl alcohol and add the washings to the flask.

3. Shake the contents of the flask manually or in a mechanical shaker for about half an hour and then filter,

4. Transfer the filtrate to a separating funnel and extract calcium nitrate completely with water in five to six instalments.

5. A few drops of dilute hydrochloric add may be added during the extraction with water to avoid formation of an emulsion of amyl alcohol with water.

6. Concentrate the water extract at low temperature to nearly half its volume. 7. Transfer the concentrated solution to a conical flask, and 5 ml of ammonium chloride- ammonium hydroxide buffer Rolution, ; drops of eriochromc black T indicator solution and titrate against standard EDTA solution to a pure blue end point.

Calculations

8-2 NV

Calcium nitrate per cent by weight •=

W

Where N—normality of Btandard EDTA solution

V=Volume in ml of standard EDTA solution used in the titration, and W-= Weight In 8™of the material taken for test.

(Reference : IS specifications of CAN IS : 2409-1963)

3.16 Determination of Chlorides other than ammonium chloride.

Rtagents

1. Standard silver nitrate solution—o-i N

2. Concentrated nitric acid—conforming to I S: 264-1950 3. Ferrous ammonium sulphate solution saturated in water and stabilized by addition of 50 ml nitric acid.

4. Standard Ammonium thiocyanate/aolution—o-iN

Procedure

1. Dissolve atcuT 0 ' 2 fB of the prepared sample/ previously dried as in procedure for d* teimJrriici d mcitfvie ai 0 accurately weighed, in about 40 ml water.

2. Add exactly 50 ml of standard silver nitrate solution and 5 ml of concentrated nitric add. 3. Addo-5 ml of nitrobenzene and make up the volume of the mixture to exactly ioomlwith water.

4. Take exactly 50 ml of the solution and add 2 ml of ferric ammonium sulphate solution. £. Titrate the excess of silver nitrate in this portion with standard ammonium thiocyanato solution,

6. Carry out a blank teat following the procedure given as above but without using the ma- terial.

Calculations

Total chlorides (as cl) per cent

7.07 (Vj-V.) N

by weight (on dry basic) — X

where W

Vi—Volume in ml of standard ammonium thiocyanate used in the blank determination. V,=Volume in ml of standard ammonium thiocyanate solution used in the test with [the material.

N-= Normality of standard ammonium thiocyanate solution. W—Weight in gm of the drived prepared sample taken for the test.

Express the ammoniacal nitrogen content per cent by weight of the material determined earlier in terms of Cl as follows :

Chloride equivalent of the ainrnoniacal nitrogen content, per cent by wcight.=2l53i x A Y

where a^fs the ammoniacal nitrogen content determined earlier.

Balanced chloride equivalent to sodium chloride (MaG)3perccnt by weights 1-648 x (x—y).

(x—y)— Balanced chlorides other than ammonium chloride.

(Reference IS Specification for ammonium chloride fertiliser grade (Revised) I S: 1114-1964 calculations modified.)

4JMUrminalion of phosphates

Mittuis of d-tcrmination of total phosphates, water soluble phasphatcs, citrate soluble phos- phate^, citrate insoluble ohosphites and citric acid soluble phosphates have been described sepa- rately in this section. These methods are applicable to straight as well as mixed phoephatic fer- tilisers,

4.1 Preparation of solution of iht samplto

(Separate methods of preparing solutions of the samples have been described according to the nature of the sample).

Rtagmt

Magnesium nitrate solution—Dissolve 95O"gm P—free Mg (NO3) ,.6H,O in water and^dilute to I litre.

Procedure

1. Treat 1 gmsampleby(a), (b), lc),(d) or (c)m;thoi;depitiJlngonthenature ofthesample .

%. Cool solution transfer to 200 to 250 jmi volumetric fliskj dilute to volume mix and filter through dry filter.

(a) (Suitable for materials containing small quantities of organic matter). Dissolve in

30 ml HNO3 and 3—5 ml H cl and boil until organic matter is destroyed.

(b) (Suitable for fertilisers containing much Fe or Al phosphate and basic slag). Dissolve

in 15—30 ml Hcl and 3—10 ml HNO3,

(c) (Suitable for "organic material like cotton seed meal alone or in mixture). Evaporate

with 5 ml of the Mg (NO,3)2 solution, ignite and dissolve In Hcl.

(d) (Generally applicable to materials or mixtures containing large quantities of organic mattcrj. Boil with 20—30 ml H2S04 in 200 ml flask adding 2—4 gm of NaNO.KNO, at beginning of digestion and small quantity after solution is nearly colourless, or adding the nitrate in small portions from time to time. When solution is colourless, cool add 150 ml water and boil for few minutes. Before adding NaNO, or KNOM let mixture digest, at gentle heat if necessary, until violence of reaction ia over.

(e) (Suitable for all fertilisers). Boil gently for 30—45 minutes with 20—30 ml HNO, in a suitable flask (Preferably a Kjeldahl for samples containing large quantities of organic matter to oxidize all easily oxidizable matter). Cool and add 10—20 ml of 70—72 per cent perchloric acid. Boil very gently until solution is colourless or nearly so and white dense fumes appear in flask. Do not boil to dryness at any time (Danger I). (With samples containing large quantities of organic matter temperature should be raised to fuming point approximately 170° Ci over a period of 1 hour at least). Cool slightly, add 50 ml water and boil for few minuteB.

4.2 Gravimetric Qtdnoline, Mclyldate method for determination'of total phosphorus.

Rtagi.tls

1/ Citric molybdic acid reagent—Dissolve 54 gm, 100 per cent molybdic anhydride (M^O,) andl2 gmNaOH withstirringin400mlhot waterandcool. Dissolve 60 gm citric acid in mixture of 140 ml HC1 and 300 ml water and cooL Gradually add molybdic solution to citric acid solution •with stirring. Cool, filter and dilute to I litre. (Solution may be green or blue, colour depends on exposure to light). If necessary add 0.5 per cent KBrO, solution drop by drop until green colour becomes pale. Store in dark in polyethylene bottle.

2. Qulnoline solution—Dissolve 50 ml synthetic quinolino with stirring in mixture of 60 ml HC1 and 3O, ml. water. Cool dilute to 1 litre, and filter. Store la polythylene bottle.

3. Qulraociac reagent—Dissolve 70 gm of sodium molybdate dihydrate In 150 ml water. Dissolve 60 gm citric acid In mixture of 8$ ml HNO3 and 150 ml water and cool. Gradually add molybdate solution to citric acid-nitric acid mixture with stirring. Dissolve 5 ml synthetic quino- ilnein mixture of 35ml HNO, and 100 ml water. Gradually aidthis solution to nulybdate citric- nitric acid solution mix and let it stand for 24 hours. Filter, add, aS ml acetone, alluto to 1 litre -with water and mix well. Store in polyethylene bottle.

Proadure

1. Treat 1 gm aamplc as prescribed in 4.1 and dilute it to 200 ml.

2. Pipette into 500 ml erlenmeyer flask, aliquot containing not mire than 25 mgP,O, dilute to . approximately 1O0 ml with water. Proceed with one of the following method ".

(a) Add 30 ml citric molybdic acid reagent and boil gontly for 3 minutes. (Solution must be precipitate free at this stage). Remove from heat and swirl carefully. Immediately add fror* [burette IO ml quinoline solution with continuous swirling, (Add first 3-4 ml dropwiie and re- mainder in steady stream) or

(b) Add jo ml quimsciac reagent) cover with watch glass place on hot plate in well ventilated ihoodj and boil for 1 minute.

After treatment with (a) or (b) cool to room tem?;cature, swirl carefully 3-4 tim^s durinf -cooling, filter into gooch with glasB fibre filter papjr previously dried at 25O⁰ G and weighed, tnd wash five times with 25 ml portion of water. Dry cruicible and contents for 30 minutes at 253° C •Coolin desicctor to constant weight as (CgHjNjjH,. P04. 12 M ; , 0, Subtract weight reager* [blank. Multiply by 0.03207 to ob :aln weight of P,O4. Report as per cent P,OS. 4.3 Determination of water soluble phosphorus

Procedure

1. Place i gm sample on 9 cm filter paper and wish with strnll portion of water uutil filtrate measure approximately 250 ml.

2. Let cacti portion pass through filter before adding more and use suction if washing wo\i\i not otherwise be complete within I hour.

3. If the filtrate is turbid, add 1-2 ml HNO, dilute to 250 ml and mix.

i. Pipette into 500 ml erlcnmeyer flask aliquot containing not more than 25 raj PzO,.

5. Dilute if necessary to 50 ml.

6. Add 10 ml HNO, (1 plus 1) and boil gently for 10 minutes. Cool and dilute to 100 ml and [proceed as 4.2 (b).

(Reference "Methods of Analysis, AOAC).

.4.4 Citrat* Insoluble phosphorus.

Reagents

1. Ammonium citrate solution—should have specific gravity of 1-09 at 23°C and pH of 7-0 "s determined electrometrically.

Dissolve 370 gm crystalline citric acid in 1-5 litre distilled water and nearly neutralize by .adding 345 ml NH4OH (28-29%NHS). Ifconcentrationofammoniaislessthan28 per cent add correspondingly larger volume, and diswlve citric acid in correspondingly smaller volume of •water, Cool and check pH. Adjust with NH4 OH (1 plus 7) or citric acid solution to pH7 Dilute solution if necessary to specific gravity of 1 • 09 at 20"C. (Volums will b; approximately 2 litres) Keep in tightly stoppered bottles and check pH from time to time. If pH has charmed from 7-0, readjust.

2. Other reagents and solutions as in 4,1 and 4.2.

Procedure (Acidulated samples and mixed fertilisers).

1. After removing water soluble P , 0, in 4-3 transfer filter and residue within r hour to 200]or 250 ml flask containing 100 ml ammonxium acetate solution previously heated to 65*C

2. Close flask tightly with smooth rubber stopper.

3. Shake vigorously until paper is reduced to pulp and relieve pressure by removing stopper Momentarily.

4. Continuously agitate contents of stopper flask in apparatus equipped to hold contents of flask at exactly 65°C. (Action of apparatus should be such that dispersion of Bample in citrate- solution is continually maintained and entire inner surface of flask and stopper is continually bathed with solution).

5. Exactly 1 hour after adding filter and residue, remove flask from apparatus, and immediately filter contents by suction as rapidly as possible through whatmanNo. 5 paper or equivalent, usinfj buchncr or ordinary funnel with platinum or other cone.

6. Wash with distilled water and at 65°C until volume of filtrate is approximately 350 ml, allowing time for thorough draining before adding more water.

7. If material is one that will yield cloudy filtrate,, wash with 2 per cent NH

8. Determine P,O, in citrate insoluble residue by one of the following methods:

(0 Dry paper and contents, transfer to crucible, Ignite until all organic matter is destroyed, anu digest with 10-15 ml HC1 until all phosphate dissolve, or (2) treat wet filter and content*, •s in ^method prescribed in 4-1 (a), (c), (d) or (c). Dilute solution to 250 ml or other suitable- volume, mix well filter through dry paper and determine P,Oj as in 4-2.

(Reference "Methods of Analysis" AOAC, 1965).

4 .5 Citrate soluble phosphorus

Subtract sum of water soluble and citrate insoluble P,O, from total P,Ot to obtain citrate soluble P.O..

(Reference "Methods of Analysis" AOAC, 1965).

4.6 Citric acid soluble PiP* in fertilisers otter than basic slag

Reagents

1. Concentrated hydrochloric acid

2. Concentrated nitric acid

3. Calcium oxide finely ground

4. 5 N Sodium hydroxide solution.

5. Dilute hydrochloric acid—Dilute 240 ml of concentrated hydrochloric acid with water tc* 1 Htte.

6. Citric molybdic add solution—Stir 54 gm of molybdic anhydride (MOO,¹) with 200 ml of water, add 11 gm of sodium hydroxide and stir the mixture whilst heating to boiling point until' the molybdic anhydride dissolves. Dissolve 60 gm of citric acid in about 250 to 300 ml of water and add 140 ml of concentrated hydrochloric acid. Pour the molybdate solution into the acid' solution, which is stirred throughout the addition. Then cool and if necessary filter the solution through paper pulp pad. Dilute the solution to 1 litre. If the solution is slightly green or blue in colour add dropwisc a dilute (0-5 to i-o per cent) solution of potassium bromate until the colour is discharged. This reagent should be kept in dark.

7. Quinoline solution—Measure 60 ml of concentrated hydrochloric acid and 300 to 400 ml of water into a 1 litre beaker and warm to 70⁰—8o°C. Pour 50 ml of quinoline in a thin stream into - the gilute acid whilst stirring. When quinoline has dissolved, cool the solution dilute to I litre, and if necessary filter through a paper pulp filter.

8. Sodium hydroxide solution—0-5 N carbonate free,

11. Sodium.'hydroxide solution—O'iN.

12. Hydrochloric acid—o-i N.

13. Surface active agent —o-j per cent solution of sodium dodecyl benzene sulphonate:

s suitable.

P^paraHon of solution

1. Weight to the nearest mg abotn. 3 gm of the sample and transfer to a stoppered bottle of about 1 litre capacity.

2. Dissolve 10 gm of pure crystallized citric acid (monohydrate)in water, dilute to SCO ml and adjust the temperature to 20°C.

3. Add the solution to the SEmple in the bottle, shfkirg so ss tc

5. Pour thewholeoftheliquidatonceon-to a large meditrr-. fire filter srd'collect the filtrate. If the filtrate is not clear, pass it again through the same filter.

Procedure

1. Transfer a volume of the solution prepared according to procedure'given above contain ing less than 70 mg of phosphoric acid end piefeistlj about 50 rr.g to a <;co ml s t o r r a ed conical flask marked at 150 ml.

'

2. Dilute the solution with water to 100 ml.

3. If the sample does not contain calcivm add ico to 2cc mg of calcivm carbonate.

4. Then a d ds N sodium hydroxide solution dropwise until a faint r e i i r ; r c rt titf r it* or precipitate is formed.

' 5. Dissolve the precipitate by the drcrwiEe addition' of dilute hydrcchlcr'c ted t ut avoid an excess.

' ' ' '

s 6. Dilute to 150 ml and add 50 ml of the citric-molytdic rcid reEgerit. srd rest the "olr. tion to incipient ebullition, maintain it at this temperature for 3 mirutes i rd t t tn t r i r e it 10 l ie boiling point.

7. From burette slowly add 25 ml of the quinoline solution withconsUm'swirlirg tbrcvgrcvt the first few ml, being added dropwise, the rest in a slow stream.

8. Keep the solution gently boiling during the addition.

9. Immerse the flask in boiling water for 5 minutes, then cool it to 15⁰ C, in running water.

10. Filter with suction the contents of the flask on a paper pulp ptd, ard wash ire fk

11. Transfer the filter pad! and precipitate to the original flask, rinse the funnel with watesh and collect the rinsings in the flask.

12. If necessary, wipe the funnel with small piece of damp filter psrer to ensure ccmckte removal of the precipitate, and place the paper in the flask.

13. Add water to a total of about but not exceeding ico ml. Stopper the flask and shske it?

vigorously until the pulp and precipitate are completely dispersed.

14. Remove the stopper and wash it with water, returning the washings of the flask.

15. Add a measured volume of 0-5 N sodivm hjdroxie'e solut.cr n ffckrt tc di"chc ire • precipitate and leave a few ml in excess.

16. Shake the flask vigorously until all the precipitate dissolves. (To ftcilitate ire djereissi - of the precipitate, after the addition of 0-5 N sodium hydroxide solution, a few drors of the surface active agent may be added if necessary).

17. Add 0 • 5—1 • o ml of the indicator solution, and titrate t'he excess of sodivm hydroxide with 0-5 N hydrochloric acid, until the indicator changes from violet to green-blvei, srd tren very sharply to yellow at the end point.

18. Deduct the number of ml of 0-5 N hydrochloric acid used from the number of ml 0-5 N sodium hydroxide, to ascertain the volume of 0^5 N sodium hydroxide equivalent to the , phosphoric acid.

191. Carry out a blank determination on all the reagents, omitting only the sample, and m t i? :>• t N i c n i i ri llfcili a il acid instead of 0-5 N for the titration. Calculate the blank ia term? of o- 5 N alkali and subtract it from the original result.

20. Cilcilatc th- < n o nt of phosphoric acid in the portion taken for analysis from the "factor i - o m l of 0-5 N sodium hydroxide—1-366 mgP,O,.

(Reference Statutory Instruments i960. No. 1165, Agriculture, the fertilizer and feeding stuffs Regulations, i960).

. 4 .7 Free Phosphoric acid (as P"O,)

, Reagents

.1, Acetone—conforming to IS : 170-1950 specification for acetone,

2. Standard sodium hydroxide solution—o*i N

3. Bromocresol green indicator solution—Dissolve o-1 grms of bromocrcsol green in 100 ml.

"f rectified spirit conforming to IS : 323-1959 specification for rectified spirit (Revised).

Procedure

1. Weigh accurately about 2'5 grms. of] the prepared sample and transfer to a soxhlct .x tractor.

2. Add about 100 ml of acetone and extract for three hours.

3. Cool and distil off the acetone as far as possible.

4. Take up the residue with water and make up the volume to 250 ml

5. Pipette out exactly 100 ml of this solution and titrate with standard sodium hydroxide solution, using bromocresol green as indicator, until colour Just changes from yellow to blue.

, alculations

Free phosphoric acid (as P,Oj)

Per cent by weight _ i 7 - 7 5 x V xN

W

V—volume in ml of standard sodium hydroxide solution used.

N ""normality of standard sodium hydroxide solution, and W—weight in grms. of sample taken for the test. [Reference IS specification for superphosphate (Revised) ISI : 294-1962]

5. Determination of Posstaium

Determination of Potassium In all kinds of fertilizers is given in this section. Two alternative methods have been described. Any of these two methods may be used depending upon the availability of reagents, and suitability of the method.

5.1 Perchloric Acid method

(This method depends on the unsolubility of potassium perchlorate and the solubility of sodium pcrchlorate in alcohol, and is applicable in presence of alkali metals, chlorides and nitrate*. Sulphates and ammonium salts must be absent on account of the low solubility of sodium sul-. phate and of ammonium perchlorate in alcohol. Phosphates must be removed. Methods arc given for the elimination of the effect of interfering substances.)

Reagents

1. Concentrated hydrochloric acid.

2. Barium chloride solution—Dissolve 100 grm8. of barium chloride in water, filter , olution and dilute to 1 litre.

3. Dilute hydrochloric acid—Dilute 240 ml. of concentrated hydrochloric acid with water tt>~ 1 litre.

4. Calcium oxide—Finely ground.

5. Ammonium hydroxide solution—sp. gr. o-88

6. Ammonium carbonate solution—Saturated aqueous solution.

7. Ammonium oxalate solution—Saturated aqueous solution.

8. 20 per cent per chloric acid solution.

p. Alcohol—industrial methylated spirit 95-96 per cent V/V.

10. Wash solution—Add potassium per chlorate to alcohol and shake until a saturated solu- tion is obtained. Keep the solution over solid potassium perchloratc and filter immediately before use.

Potassium salts free from sulphates and other interfering substances.

1. Dissolve in water a portion of the sample weighed to the nearest mg. equivalent to potas- sium content to 1-5 to 2 • o grms. of potaBh.

2. Cool the solution to 20⁰ C, dilute to 500 ml. in a volumetric flask, mix well and filter through.

• dry filter.

3. Determine the potash in the 50 ml of solution by precipitating with perchloric acid as- described under procedure.

Potassium salts vnih sulphates or orher interfering substances

(The following method is given for eliminating the interference caused by presence of sul- phate. If salts contain, phosphates, iron, manganese or substances other than sulphate that interfere with the determination of potash, the method described for mixed fertilizer should be used).

1. Weigh to the nearest mg a portion of the sample equivalent in potassium content to 1 • 5 to 2-0 gm of potash, into a 500 ml. beaker. Add about 300 ml of water and 20 ml concentrated' hydrochloric acid and heat the solution to boiling,

2. To the boiling solution cautiouslyj add drop by drop, barium chloride solution in an amount slightly in excess of that previously determined a3 necessary to ensure the complete pre- cipitation of sulphate.

3. Cool the liquid to 20°C, transfer to a 500 ml. volumetric flask, dilute to 500 ml., mix and filter through a dry filter.

4. Take 50 ml of the filtrate and evaporate to dryness in a basin, moisten the residue with concentrated hydrochloric acid.

5. Again evaporate to dryness, dissolvejthe residue with 5-10 ml. dilute hydrochloric acid and filter if necessary. Determine the potaBh in the solution by the method described under procedure.

Potassium in mixed fertilizers

1. Weigh to the nearest centigram about 10 gm. of the sample and if organic matter is present, gently incinctrate at a temperature not exceeding 5oo°C.

2. Transfer the weighed portion of the sample or the incinerated residue to a 500 ml. beaker with a little water and 10 ml. concentrated hydrochloric acid and then warm for to minutes.

3. Dilute with water to about 300 ml, and bring gradually to boiling point.

4. Add 10 gm of calcium oxide made into a paste with water.

5. Bring contents again gently to the boiling point, and keep so heated for about half an hour with frequent stirring.

6. Cool to 20°C, transfer to a 500 ml. volumetric flask, dilute to 500 ml. and, after thoroughly shaking filter through a dry filter paper.

7. Transfer 250 ml. of the filtrate to another 500 ml. volumetric flask, make just acid witpj hydrochloric acid and heat to boiling point.

8. To the boiling solution cautiously add drop by drop, barium chloride solution until • there is no further precipitation of barium sulphate.

9. Render the contents of the flaak alkaline with ammonium hydroxide solution, and pre- cipitate the calcium and any excess of barium by adding of ammonium carbonate solution until 'GO further visible precipitation occurs followed by the addition of about 1 ml of ammonium oxalato solution,

10. Cool to 2o°C, dilute with water to 500 ml and, after thoroughly shaking, filter through ajiry filter paper.

11. Measure 100 ml. of the filtrate and evaporate to dryness in a basin. Expel the ammonium •salts from the residue by gently heating the basin over a low flame, being careful to keep the temperature below that of faint redness.

12. Cool the residue, moisten with concentrated hydrochloric acid and again evaporate /to dryncss.

13. Take up the residue with water and filter if necessary,

14. Determine the potash in the solution by precipitation with perchloric acid as described under procedure.

Procedure

1. Transfer the solution obtained as described above into a basin and add about 7 ml of perchloric add solution.

2. Place the basin on a hot plate or sand bath and evaporate the contents until the white fumes are copiously evolved.

3. Cool and dissolve the precipitate in a little hot water.

4. Add about 1 ml of perchloric acid solution and again concentrate to the fuming stage.

5. Thoroughly cool the residue in the basin and stir in 20 ml of alcohol,

6. Allow the precipitate to coal and settle, then pour the clear liquid through a dry filter ipipjr, draining the precipitate in the basin and stir in 20 ml of alcohol.

7. A.U01V th; precipitate to cjal and settle, th:n p j jr tin clear liquid through a dry filter papir, dtiin the precipitate in the basin as completely as possible.

8. Redissolve the precipitate on the paper and that remaining in the basin with hot water.

9. A di 2 ml of per chloric acid solution to the combined solution and evaporate the whole down to the fuming stage.

10. Cool the residue in the basin and thoroughly stir the contents with 20 ml of alcohol.

11. Allow the precipitate to cool and settle and pour the clear liquid through a weighed good or Bintered glass crucible, draining the precipitate as completely as possible from the liquid before adding 5 ml of wash solution.

12. Wash the precipitate by decantation with several similar small portions of the wtth •olution, pouring the washings through the crucible.

13. Transfer the precipitate to the crucible and wash it well with the wash solution until free from acid.

14. Dry the precipitate at ioo° C and weigh.

15. Regard the precipitate as potassium perchlorate (KC1O,) and calculate its equivalent ;M potash K ,0 by multiplying its weight by 0-34,

(Reference statutory Instruments i960. No, 1165, Agriculture, the fertilizer and Feeding stuffs Regulation i960).

5'2 Sodium Tetraphenylboron Method

This method is applicable to both mixed and straight potassium fertilizers.

ReagfnU

(a) Sodium hydroxide solution—20 per cent. Disssolve 20 gm NaOH in 100 ml distilled water.

(b) Formaldehyde solution—37 per cent.

(c) Sodium tctraphenylboron (STB) Solution—Approximately 1-2 per cent. Dissolve 12 gm sodium tetraphenylboron in approximately 800 ml water. Add 20-25 8™ Al(OH),, stir for 5 minutes, and filter (whatman No. 42 paper or equivalent) into 1 litre volumetric flask. Rinse beaker sparingly with water and add to filter. Collect entire filtrate, add 2 ml 20 per cent NaOH solution, dilute to volume with water, and mix. Let it stand for 48 hours and standardize. Adjust so that 1 ml^STPB-ni per cent K,O. Store at room temperature.

(d) Quaternary ammonium chloride solution.—

Approximately CV625 per cent. Dilute 50 ml of 12 '8 per cent Zephiran chloride to 1 litre "with water, mix and standardize. Cetyltrimcthyl—ammonium bromide may be substituted for Zephiran chloride. If other concentration is used, adjust volume.

(e) Clayton yellow—0-04 per cent, Dissolve 40 mg in 100 ml water.

Standardization of Solution

(a) Zephiran chloride—To i-o ml STB solution in 125 ml erlenmeyer flask, add 20-25 ""1 water, 1 ml 20 per cent NaOH, 2-5mlHCHO, 1 • 5 ml 4 per cent (NH4)a CaOt and 6-8 dropi of iirlicatorCe).

(b) Titrate to pink and point with Zephirarn chloride solution, using 10 ml semimicro buret.

Adjust Zephiran chloride solution so that 2-0 ml— i-o ml STPB solution.

(c) Sodium tetraphenyl boron solution—Dissolve 2 • 5 gm of KH, PO4 in water in 250 ml •volumetric flaak, add 50 ml 4 per cent (NH4)i C|O4 solution, dilute to volume with water and mix. (It is not necessary to bring to boil). Transfer 15 ml aliqjot (51-92 mg K,O, 4 3-IO mg K) to 100 ml volumetric flask, add 2 ml 20 per cent NaOH, 5 ml HCHO and 43 ml STPB reagent. Dilute to volume with water, mix thoroughly, let stand 5-10 minutes and pass through dry filter. Transfer 50 ml aliquot of nitrate to 125 ml erlenmeyer flask, add 6-8 drops of indicator(c) and titrate excess reagent with Zephiran solution. Calculate titratic value as follows :

F=34-6i/(43ml—mlZcphiran) = % KsO/ml STPB reagent. Factor applies to all fertilizer* if 2-5 gm sample is diluted to 250 ml. and 15 ml aliquot is taken for analysis. If results are to be expressed as K rather than K,O, substitute 28 • 73 for 34 • 61 in calculat- ing the value of F.

Preparation of solution

1. Place 2 • 5 gm. sample or factor weight 2 • 430 gm in 250 ml, volumetric flask.

2. Add 125 ml water and 50 ml saturated (NH4)4 C,O4 solution. Add 1 ml of diglycol stearate solution if needed to prevent foaming.

3. Boil for 30 minutes, add slight excess of NH4OH and after cooling dilute to 25o mL Mix and pass through dry filter.

;t>) Poras3ium salts (Potassium chloride, sulphate, potassium migru3ium sulphate, and kairuit).

1. Dissolve 2 • 5 gm or factor weight 2 • 430 gm and dilute to 250 ml without adding NH4OH

and (NHj,C,O,.

2. When interfering substances such as NH,, Ca, Al etc. are present, proceed as in (a).

Procedure

1. Transfer 15 ml aliquot of sample solution to 100 ml volumetric flask and add 2 ml. 20 [per cent NaOH and 5 ml HCHO.

2. Add 1 ml standard STPB solution for each I per cent K^O expected in sample plus addi- tional 8 ml excess to insure complete precipitation,

3. Dilute to volume with water, mix thoroughly let it stand for 5-10 minutes and pass lr tbrough dry filter (whatman 12 or equivalent).

4. Transfer 50 ml filtrate to 125 ml erlcnmeyer flask, add 6-8 drops of indicator(e) and titrate excess reagent with standard Zephiran Solution.

%K,O in the sample=(ml STPB added—ml Zephiran) x F,

where F=%K,O/ml,STPB reagent.

(Reference "Methods of Analysis", AOAQ, 1965.)

(10) In the said Order, in Form 'A', for Note (1) the following Note shall be substituted ""mc}y :—

NOTE : (i) Where the business of selling fertilisers is carried on at more than one place " separate application should be made for registration in respect of each such place, (11) In the said Order, for Form 'B', the following Form shall be substituted, namely:

EMBLEM

FORM 'B'

(See clause 7)

Mock No.

Registration No Date of Issue Valid upto

-

Certificate of Registration to carry on the Business of Dealer in Fertilisers in the State of

is hereby granted certificate •f registration to carry on the business of selling fertilisers at the place prescribed below in the State subject to the terms and conditions specified below and to the provisions of the Fertiliscr (Control) Order, 1957.

Description of the place of business

Name or style by which the Location of sale depot Location of godowr.i businens is carried on

attached to sale depot

Date :

Registering Authority

State of H

SMI

Terms and conditions of certificate of registration

1. This certificate of registration shall be' displayed in a prominent and conspicuous place in a part of the business premises open to the public.

2. The holder of the c;rtiflcatc shall comply with the provisions of the Fertiliser (Control) Order, 1957 and the notifications issued thereunder for the time being in force.

3. The certificate or registration shall come into force immediately and be valid upto the 31st March, 19 unless previously cancelled or suspended.

4. The holder of the certificate shall from time to time report to the-Registering Authority any <-hango in the premises where he carries on his business of selling fertilisers.

5. The dealer shall sub-nit a report to the Registering Authorityj with a copy to the Block Development Officer or such officer as the State Government may notify in whose Jurisdiction the place of business is situated, by the 5th of eyery month, showing the opening stock, receipts, sale and closing stocks of fertilisers in the prccoding month. He shall also submit in time such other returns as may be prescribed by the Registering Authority.

f. The dealer transacting retail sales shall kee^ in stock for sal" fertilisers having nitrogenous phewphatic (P,Oj) and potash nutrients separately or jointly, provided that the nutrient stock of phosphate (P,O,5 and potash (K^O) together shall not be less than 20% of the nitrogen in stock.

NoTfl : (1) Where the business of selling fertilisers is carried on at more than one place a separate registration certificate should be obtained in respect of each place.

(12) After Form 'EB' of the said Order, the following forms shall be inserted, namely:—

EMBLEM

FOBM T¹

[Sea Clause 13 (B)J

Application for grant of permission to sell non-standard fertilisers

To

The Registering Authority State of

1. Full name and address of the applicant.

2. The name of fertilisers in which the applicant has been authorised to carry on business.

3. Number and date of registration certificate granted in favour of the applicant.

4. The particulars of non-standard fertilisers which are intended to be sold:

(i) Name of the fertiliser.

(il) The source from which the fertilisers were originally purchased and the period during which they have been held by the applicant. Brief reasons leading to the material having become non-standard.

(iii) The chemical specifications as analysed by an authorised chemical laboratory.

(iv) Name and appearance of the non-standard fertiliser.

NOTE : Chemical analysis to bo indicated shall be one which has been certified bv an authorised chemical laboratory on the basis of the samples drawn, sealed and despatched in the presence of the local Inspector of Fertilisers or anybody authorised to inspect the fertilisers.

I enclose a copy of the certificate of registeration for dealing in fertilisers already granted to me and I have deposited the prescribe,! fee for permission to sellnon-standara fertilisers.

I certify that I will comply with the requirements of sub-clause(a) of Clause i"}(B) of the Fertiliser Control Order, 1957 which requires that each container of non-standard fertilisers is to be conspicuously superscribed with the words 'Non-Standard'and also with the sign "X", both in red colour.

Signature of the applicant.

EMBLEM

FORM 'G'

[See Clause I3(B)]

Book No.

Date of issue :

Valid upto (the period of validity will not exceed 4 months from the date of issue).

Permission for the sale of non-standard fertilisers

M/s

ia/are hereby permitted to sell the non-standard fertilisers described below subject to the terms and conditions noted hereunder :—

Particulars of non-standard fertiliser

1. Name of the- fertiliser

2. Detailed chemical specifications including the nutrient content.

1. Nature and appearance of the non-standard fertiliser.

4. Place of location of the non-standard fertiliser.

Terms and conditions

1. The seller of the nou-staidard fertiliser m described above shall comply with the provi- sions of sub-clause(e) of Clause u(B) of the Fertiliser Control Order, 1957.

2. The non-standard fertilisers as described above shall be sold *t a price not exceeding..

per metric tonne or per bag of kgs*

3. If the non-standard material described above is not sold before a fresh permission will DO necessary before the non-standard fertiliser can be sold.

Date

Registration Authority Seal

State of

[No. 16/17/68-M.]

S. M. H. BURNEY, Jt.Secy.