DIN EN 16075-2012 Fertilizers - Determination of N-(2-nitrophenyl)phosphoric triamide (2-NPT) in urea and fertilizers containing urea - Method using high-performance liquid chromat.pdf

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1、January 2012 Translation by DIN-Sprachendienst.English price group 8No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS

2、 65.080!$y+6“1860819www.din.deDDIN EN 16075Fertilizers Determination of N-(2-nitrophenyl)phosphoric triamide (2-NPT) in ureaand fertilizers containing urea Method using high-performance liquid chromatograph (HPLC)English translation of DIN EN 16075:2012-01Dngemittel Bestimmung von N-(2-Nitrophenyl)P

3、hosphorsure-Triamid (2-NPT) in Harnstoff undharnstoffhaltigen Dngemitteln Verfahren mit Hochleistungs-Flssigchromatographie (HPLC)Englische bersetzung von DIN EN 16075:2012-01Engrais Dosage du N-(2-nitrophnyl) triamide phosphorique (2-NPT) dans lure et les engraiscontenant de lure Mthode par chromat

4、ographie liquide haute performance (HPLC)Traduction anglaise de DIN EN 16075:2012-01www.beuth.deDocument comprises pagesIn case of doubt, the German-language original shall be considered authoritative.12y01.12 DIN EN 16075:2012-01 2 A comma is used as the decimal marker. National foreword This stand

5、ard has been prepared by Technical Committee CEN/TC 260 “Fertilizers and liming materials” (Secretariat: DIN, Germany). The responsible German body involved in its preparation was the Normenausschuss Lebensmittel und landwirtschaftliche Produkte (Food and Agricultural Products Standards Committee),

6、Working Committee NA 057-03-02 AA Dngemittel. The DIN Standards corresponding to the International Standards referred to in this document are as follows: EN ISO 3696 DIN ISO 3696 ISO 5725-1 DIN ISO 5725-1 ISO 5725-2 DIN ISO 5725-2 National Annex NA (informative) Bibliography DIN ISO 3696, Water for

7、analytical laboratory use Specification and test methods DIN ISO 5725-1, Accuracy (trueness and precision) of measurement methods and results Part 1: General principles and definitions DIN ISO 5725-2, Accuracy (trueness and precision) of measurement methods and results Part 2: Basic method for the d

8、etermination of repeatability and reproducibility of a standard measurement method EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 16075 November 2011 ICS 65.080 English Version Fertilizers - Determination of N-(2-nitrophenyl)phosphoric triamide (2-NPT) in urea and fertilizers containing urea -

9、 Method using high-performance liquid chromatography (HPLC) Engrais - Dosage du N-(2-nitrophnyl) triamide phosphorique (2-NPT) dans lure et les engrais contenant de lure - Mthode par chromatographie liquide haute performance (HPLC) Dngemittel - Bestimmung von N-(2-Nitrophenyl)Phosphorsure-Triamid (2

10、-NPT) in Harnstoff und harnstoffhaltigen Dngemitteln - Verfahren mit Hochleistungs-Flssigchromatographie (HPLC) This European Standard was approved by CEN on 24 September 2011. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this Eu

11、ropean Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versi

12、ons (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria,

13、Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN

14、COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 16075:2011: EEN 16075:2011 (E) 2

15、Contents Page Foreword 31 Scope 42 Normative references 43 Terms and definitions .44 Principle 45 Reagents .46 Apparatus .47 Sampling and sample preparation .58 Procedure .58.1 Preparation of the test solution 58.2 Preparation of the test solution in the presence of paraffins as conditioning agents

16、58.3 Preparation of the calibration solutions 58.4 HPLC conditions 68.5 HPLC determination 69 Calculation and expression of the results 69.1 Calculation 69.2 Expression of results 710 Precision .710.1 Inter-laboratory test .710.2 Repeatability .710.3 Reproducibility .711 Test report 8Annex A (inform

17、ative) Statistical results of the inter-laboratory test 9Bibliography . 10DIN EN 16075:2012-01 EN 16075:2011 (E) 3 Foreword This document (EN 16075:2011) has been prepared by Technical Committee CEN/TC 260 “Fertilizers and liming materials”, the secretariat of which is held by DIN. This European Sta

18、ndard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by May 2012, and conflicting national standards shall be withdrawn at the latest by May 2012. Attention is drawn to the possibility that some of the elements of this do

19、cument may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. According to the CEN/CENELEC In

20、ternal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Lux

21、embourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. DIN EN 16075:2012-01 EN 16075:2011 (E) 4 1 Scope This European Standard specifies a method for the determination of N-(2-nitrophenyl)phosphoric triamide (2-NPT) in u

22、rea or in fertilizers containing urea using high-performance liquid chromatography (HPLC). 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest editio

23、n of the referenced document (including any amendments) applies. EN 1482-2, Fertilizers and liming materials Sampling and sample preparation Part 2: Sample preparation EN 12944-1:1999, Fertilizers and liming materials and soil improvers Vocabulary Part 1: General terms EN 12944-2:1999, Fertilizers a

24、nd liming materials and soil improvers Vocabulary Part 2: Terms relating to fertilizers EN ISO 3696:1995, Water for analytical laboratory use Specification and test methods (ISO 3696:1987) 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 12944-1:1999 a

25、nd EN 12944-2:1999 apply. 4 Principle The sample of fertilizer is dissolved in water or extracted with water. 2-NPT is determined using reversed phase high-performance liquid chromatography with an UV detector. 5 Reagents Use only reagents of recognized analytical grade and distilled or demineralise

26、d water (conductivity less than 0,5 mS/m, according to EN ISO 3696:1995, grade 3). 5.1 2 N-(2-nitrophenyl)phosphoric triamide, of known purity. 5.2 Standard solution of 2-NPT, = 1 g/l. Weigh 1 /R g of 2-NPT, where R is the purity of 2-NPT, to the nearest 0,1 mg into a 1 000 ml measuring flask. Disso

27、lve with water, make up to the mark with water and mix well. This solution is stable for about 4 weeks. 5.3 Methanol. 5.4 n-hexane. 6 Apparatus 6.1 Analytical balance, measuring accuracy 0,1 mg or better. DIN EN 16075:2012-01 EN 16075:2011 (E) 5 6.2 Ultrasonic bath. 6.3 Syringe filter, for aqueous s

28、olutions; pore size 0,45 m. 6.4 HPLC device. 6.5 Sampling issuing system. 6.6 UV detector. 6.7 Reversed phase HPLC column1). 6.8 Laboratory glassware. 7 Sampling and sample preparation Sampling is not part of the method specified in this document. A recommended sampling method is given in EN 1482-1.

29、 Sample preparation shall be carried out in accordance with EN 1482-2. 8 Procedure 8.1 Preparation of the test solution Weigh approximately 5 g of the sample (m) into a 100 ml volumetric flask to the nearest 0,1 mg, add approximately 70 ml of water, dissolve in the ultrasonic bath (6.2) and make up

30、to the mark with water. Filtrate this solution straight into a vial through a syringe filter (6.3) to remove any conditioning agents. This solution is used for the determination. NOTE If paraffin is used as conditioning agent, see 8.2. 8.2 Preparation of the test solution in the presence of paraffin

31、s as conditioning agents Weigh approximately 5 g of the sample (m) into a 100 ml measuring flask to the nearest 0,1 mg, add approximately 70 ml of water, dissolve in the ultrasonic bath (6.2) and fill up to the mark with water. Add 2 ml of n-hexane (5.4) to this solution, shake thoroughly and fill t

32、he solution into a separation funnel. The n-hexane with the dissolved paraffin lies above the aqueous phase with the active substance. Filtrate the aqueous phase straight into a vial through a syringe filter (6.3). 8.3 Preparation of the calibration solutions To obtain the calibration curve, prepare

33、 the following dilution series according to Table 1 from the 2-NPT standard solution (5.2) (each in a 100 ml measuring flask): 1) Synergi Fusion-RP80 4 m, 250 mm 4,6 mm or equivalent. This is an example of a suitable product available commercially. This information is given for the convenience of us

34、ers of this document and does not constitute an endorsement by CEN of this product. DIN EN 16075:2012-01 EN 16075:2011 (E) 6 Table 1 Preparation of the dilution series Mass concentration of 2-NPTmg/l Volume of standard solution (5.2) l 0,5 50 1,0 1005,0 500 10,0 1 00020,0 2 000 The calibration solut

35、ions shall be prepared daily. 8.4 HPLC conditions Column temperature: room temperature Elution agent: water/methanol mixture 50+50 (volume fraction) Flow rate: 0,5 ml/min Injection volume: 20 l Wavelength : 214 nm The elution agent shall be degassed, e.g. in the ultrasonic bath (6.2). 8.5 HPLC deter

36、mination To determine the calibration curve, inject an amount of 20 l of each calibration solution (see 8.3) three times. The calibration curve can be used to for the content determination if the correlation coefficient 0,99. NOTE The correlation coefficient is calculated in accordance with the meth

37、od of smallest squares. Inject 20 l of the test solution two times in succession. The results of these injections shall be within the calibration curve. Otherwise the test solution (8.1 or 8.2) has to be diluted. 9 Calculation and expression of the results 9.1 Calculation Carry out the evaluation on

38、 the basis of the calibration curve over the peak areas. Calculate the mass fraction of 2-NPT, w2-NPT, in percent according to Equation (1): maVbAw=100pkNPT)(2(1) DIN EN 16075:2012-01 EN 16075:2011 (E) 7 where Apkis the peak area; b is the ordinate section of the calibration curve; a is the slope of

39、 the calibration curve; V is the injected volume, in litre; m is the mass of the test portion, in milligrams, prepared according to 8.1 or 8.2. After sample preparation according to 8.1 or 8.2 and in the case that the calculation of the content of 2-NPT in milligrams per litre (following the calibra

40、tion solutions given in Table 1) will be performed automatically by the software of the chromatographic system, calculate the 2-NPT content, w2-NPT, in percent according to Equation (2). 500NPT2Aw =(2) where A is the content of 2-NPT in milligrams per litre; 500 is the factor for the conversion of t

41、he mass concentration milligrams per litre in percent 2-NPT. 9.2 Expression of results Calculate the arithmetic mean from both values obtained. Indicate the result to the nearest 0,001 %. 10 Precision 10.1 Inter-laboratory test An inter-laboratory test has been carried out in 2009 with 11 participat

42、ing laboratories and 3 different samples of fertilizers. This test yielded the data given in Annex A. Repeatability and reproducibility were calculated according to ISO 5725-1 and ISO 5725-2. The values derived from this inter-laboratory test may not be applicable to concentration ranges and matrice

43、s other than those given in Annex A. 10.2 Repeatability The absolute difference between two independent single test results, obtained with the same method on identical test material in the same laboratory by the same operator using the same equipment within a short interval of time, will in not more

44、 than 5 % of the cases exceed the values of r given in Table 2. 10.3 Reproducibility The absolute difference between two single test results, obtained with the same method on identical test material in different laboratories by different operators using different equipment, will in not more than 5 %

45、 of the cases exceed the values of R given in Table 2. DIN EN 16075:2012-01 EN 16075:2011 (E) 8 Table 2 Mean values, repeatability and reproducibility limits Sample x mg/kg r mg/kg R mg/kg Urea 1 238,62 21,63 40,10 Urea 2 462,59 39,99 65,01 Urea 3 695,38 38,11 89,91 11 Test report The test report sh

46、all contain at least the following information: a) all information necessary for the complete identification of the sample; b) the test method used with reference to this document; c) the test results obtained; d) date of sampling and sampling procedure (if known); e) date when the analysis was fini

47、shed; f) whether the requirement of the repeatability limit has been fulfilled; g) all operating details not specified in this document, or regarded as optional, together with details of any incidents occurred when performing the method, which may have influenced the test result(s). DIN EN 16075:201

48、2-01 EN 16075:2011 (E) 9 Annex A (informative) Statistical results of the inter-laboratory test The precision of the method has been determined in the year 2009 in an inter-laboratory test with 11 laboratories participating and carried out on 3 samples of fertilizer. The statistical results are given in Table A.1. Table A.1 Statistical results of the inter-laboratory test Parameter Urea 1 Urea