इंटरनेट मानक Disclosure to Promote the Right To Information Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public. “जान1 का अ+धकार, जी1 का अ+धकार” “प0रा1 को छोड न’ 5 तरफ” Mazdoor Kisan Shakti Sangathan Jawaharlal Nehru “The Right to Information, The Right to Live” “Step Out From the Old to the New” IS 14832 (2000): Animal Feeding Stuff - Determination of Urea [FAD 5: Livestock Feeds, Equipment and Systems] “!ान $ एक न’ भारत का +नम-ण” Satyanarayan Gangaram Pitroda ““IInnvveenntt aa NNeeww IInnddiiaa UUssiinngg KKnnoowwlleeddggee”” “!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता हहहहै””ै” Bhartṛhari—Nītiśatakam “Knowledge is such a treasure which cannot be stolen” lS 14832 :2000 1S06654 :1991 *w’m- wpT1-m-’@”m=m T Indian Standard ANIMAL FEEDING STUFF — DETERMINATION OF UREA ICS 65.120 @ BIS 2000 BUREAU OF INDIAN STANDARDS MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG NEW DELHI 110002 September 2000 Price Group 2 Livestock Feeds Sectional Committee, FAD 5 NATIONAL FOREWORD This Indian Standard, which isidentical with ISO 6654:1991 ‘Animal feeding stuffs — Determination of urea content’ issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on the recommendation ofthe Livestock Feeds Sectional Committee and approval of the Food and Agriculture Division Council. Method of test for determination of moisture content was covered in 6 of IS 7874 (Part 1); after publication of this Indian Standard the above referred clause of 1S7874 (Part 1) will be deleted through amendment. In this adopted standard, certain terminology and conventions are not identical to those used in Indian Standards. Attention is drawn specially to the following: a) Wherever the words ‘International Standard’ appear referring to this standard, they should be read as ‘Indian Standard’. b) Comma (,) has been used as a decimal marker while in Indian Standards, the current practice is to use a point (.) as the decimal marker. In reporting the results of a test or analysis made inaccordance with this standard, ifthe final value, observed or calculated, is to be rounded off, itshall be done in accordance with IS 2:1960 ‘Rules for rounding off numerical values (revised)’. IS 14832:2000 ISO 6654:1991 Indian Standard DETERMINATION ANIMAL FEEDING STUFF — OF UREA -. 1 Scope 5 Reagents This International Standard specifies a spectro- All reagents shall be of recognized analytical grade. metric method for the determination of the urea The water used shall be distilled water or water of content of animal feeding stuffs. at least equivalent purity. 5.1 Activated carbon, which does not adsorb urea. 2 Normative reference 5.2 4-dlmethyl-amino-benzaidehyde (4-DMAB), sol- ution prepared as follows. The following standard contains provisions which, through reference in this text, constitute provisions Dissolve 1,6 g of 4-DMAB in 100 ml of 96 ?4.(V/Vj of this International Standard. At the time of publi- ethanol, add 10 ml of concentrated hydrochloric acid cation, the edition indicated was valid. All standards (P20 = 1,49 glml) and mix. are subject to revision, and parties to agreements based on this International Standard are encour- This solution may be stored for a maximum of aged to investigate the possibility of applying the 2 weeks. most recent edition of the standard indicated below. Members of IEC and ISO maintain registers of cur- 5,3 Carrez i soiution. rently valid International Standards, Dissolve In water 24 g of zinc acetate dihydrate ISO 6498:1983, Animal feeding stuffs — Preparation [Zn(CH3COO)22H20] and 3 g of glacial acetic acid. of (est samp/es. Make up to 100 ml with water and mix. 5.4 Carrez ii soiution. 3 Definition Dissolve in water 10,6 g of potassium hexa- cyanoferrate(ll) trihydrate (potassium ferrocyanide For the purposes of this International Standard, the trihydrate) {KJFe(CN)J3H20}. Make up to 100 ml following definition applies. with water and mix. urea content: The mass fraction of substances de- 5.5 Urea, standard solution corresponding to 1 g termined using the procedure specified in this inter- of urea per Iitre. national Standard. It is expressed as a percentage by mass. 6 Apparatus Usual laboratory apparatus and, in particular, the following. 4 Principle 6,1 Rotary shaker, capable of being operated at a Suspension in water of the test portion in the pres- rotational frequency of about 30 rein-f to 40 rein-l. ence of a decolorant, Stirring of the suspension, then filtration. Addition to the filtrate of 4-dimethyl-amino-benzaldehyde (4-DMAB) and 6,2 Spectrometer, suitable for measuring spectrometric measurement at 420 nm of the absorbance at a wavelength of 420 nm, and absorbance of the solution thus obtained, equipped with cells of thickness 10 mm. 1 IS 14832:2000 ISO 6654:1991 6.3 Test tubes, 160 mm x 16 mm, fitted with ground 9.4 Blank test glass stoppers. Carry out a blank test in parallel with the determi- 6.4 Volumetric flasks, of 100 ml and 500 ml capac- nation using the same procedure and the same ity. quantities of all reagents, but omitting the test por- tion. 6.5 Water-bath, capable of being controlled at 20 ‘c. 9.5 Preparation of the calibration graph 9.5.1 Pipette into a series of five 100 ml volumetric 7 Sampling flasks (6.4), 1 ml, 2 ml, 4 ml, 5 ml and 10 ml of the urea standard solution (5.5). Make each flask up to Sampling will be the subject of a future International the mark with water, One millilitre of the standard Standard. solutions contains 10 Kg, 20 ~g, 40 pg, 50 pg and 100 ~g of urea respectively. 8 Preparation of the test sample 9.5.2 Pipette into a series of five test tubes (6.3) Prepare the test sample in accordance with 5 ml of each of these solutions (9.5.1) (one dilution 1S0 6498. per test tube). Add to each test tube, by means of a pipette, 5 ml of the 4-DMAB solution (5.2) and mix. Transfer the solutions to spectrometer cells and 9 Procedure measure their absorbance at 420 nm, using the spectrometer (6.2), against a compensation solution 9.1 Test portion containing 5 ml of 4-DMAB and 5 ml of water. Weigh, to the nearest 1 mg, about 2 g of the test 9.5.3 Plot the calibration graph, with the sample (clause 8). absorbance values on the ordinate and the corre- sponding concentrations of urea, in micrograms per For urea contents greater than 3 9!o (m/m), reduce millilitre, on the abscissa. the test portion to 1 g or dilute the test solution (see 9.2) so that it does not exceed a concentration of 50 mg of urea per 500 ml. 9.6 Spectrometric measurement For low urea contents, the test portion may be in- Transfer the soiution obtained in 9.3 to a creased provided that the filtrate remains clear and spectrometer cell and measure its absorbance at colorless, 420 nm, using the spectrometer (6.2), against the blank test (9.4), 9.2 Preparation of the test solution NOTE 1 If the sample contains simple nitrogenous compounds, such as amino acids, carry out the measure- 9,2.1 Transfer the test portion (9,1) together with ment of absorbance at a wavelength of435 nm. 1 g of the activated carbon (5.1) into a 500 ml volumetric flask (6.4). Add 400 ml of water, 5 ml of 9.7 Number of determinations the Carrez I solution (5.3) and 5 ml of the Carrez II solution (5.4). Mix for 30 min using a rotary shaker Carry out two determinations on test portions taken (6,!). Make up to the mark with water, mix and filter from the same test sample. on a dense, slow, qualitative filter paper. 9.2,2 If the filtrate is coloured, prepare a fresh test 10 ExpressIon of results solution in accordance with 9.2.1 but increase the quantity of activated carbon added. The urea content, expressed as a percentage by mass, of the sample is equal to 9.3 Colour development c 20xm Transfer, by means of a pipette, 5 ml of the clear colorless filtrate (9.2) into a test tube (6.3) and add, where by means of a pipette, 5 ml of the 4-DMAB solution c is the urea content, in micrograms per (5.2). millilitre, ofthe filtrate ofthe test solution, Mix and leave to stand for 15 min in a water-bath determined from the calibration graph (6.5) controlled at 20 “C. (9.5.3); 2 IS 14832:2000 ISO 6654:1991 m is the mass, in grams, of the test portion dard, or regarded as optional, together with details (9.1). of any incidents which may have influenced the re- sult. 11 Test report The test report shall ioclude all information necess- ary for the complete identification of the sample. The test report shall specify the method used ana the result obtained. It shall also mention all operat- ing details not specified in this International Stan- 3 Bureau of Indian Standards BIS is a statutory institution established under the Bureau oj Indian Standards Act, 1986 to promote harmonious development of the activities of standardization, marking and quality certification of goods and attending to connected matters inthe country. Copyright BIS has the copyright of all its publications. No part of these publications maybe reproduced in any form without the prior permission inwriting of BIS. This does not preclude the free use, inthe course of implementing the standard, ofnecessary details, such assymbols and sizes, type orgrade designations. Enquiries relating to copyright be addressed to the Director (Publications), BIS. Review of Indian Standards Amendments are issued to standards as the need arises on the basis of comments. Standards are also reviewed periodically; a standard along with amendments is reaffirmed when such review indicates -. that no changes are needed; ifthe review indicates that changes are needed, it istaken up for revision. Users of Indian Standards should ascertain that they are in possession of the latest amendments or edit ion by referring to the latest issue of ‘BIS C@alogue’ and’ Standards: Monthly Additions’. This Indian Standard has been developed from ,Doc :No. FAD 5 (979). 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