DIN EN 16109-2012 Fertilizers - Determination of complexed micro-nutrient ions in fertilizers - Identification of lignosulfonates German version EN 16109 2011《肥料 肥料中复合微量营养离子的测定 木质素.pdf

1、January 2012 Translation by DIN-Sprachendienst.English price group 11No 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).IC

2、S 65.080!$y-“1861061www.din.deDDIN EN 16109Fertilizers Determination of complexed micro-nutrient ions in fertilizers Identification of lignosulfonatesEnglish translation of DIN EN 16109:2012-01Dngemittel Bestimmung der in Dngemitteln komplexgebundenen Spurennhrstoffionen Identifizierung von Ligninsu

3、lfonatenEnglische bersetzung von DIN EN 16109:2012-01Engrais Dosage des oligo-lments complexs dans les engrais Identification des lignosulfonatesTraduction anglaise de DIN EN 16109:2012-01www.beuth.deDocument comprises pagesIn case of doubt, the German-language original shall be considered authorita

4、tive.1901.12 DIN EN 16109:2012-01 2 A comma is used as the decimal marker. National foreword This standard has been prepared by Technical Committee CEN/TC 260 “Fertilizers and liming materials” (Secretariat: DIN, Germany) under the mandate . The responsible German body involved in its preparation wa

5、s the Normenausschuss Lebensmittel und land-wirtschaftliche Produkte (Food and Agricultural Products Standards Committee), 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 369

6、6 ISO 5725-2 DIN ISO 5725-2 National Annex NA (informative) Bibliography DIN ISO 3696, Water for analytical laboratory use Specification and test methods DIN ISO 5725-2, Accuracy (trueness and precision) of measurement methods and results Part 2: Basic method for the determination of repeatability a

7、nd reproducibility of a standard measurement method M/418EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 16109 November 2011 ICS 65.080 English Version Fertilizers - Determination of complexed micro-nutrient ions in fertilizers - Identification of lignosulfonates Engrais - Dosage des oligo-lmen

8、ts complexs dans les engrais - Identification des lignosulfonates Dngemittel - Bestimmung der in Dngemitteln komplexgebundenen Spurennhrstoffionen - Identifizierung von Ligninsulfonaten This European Standard was approved by CEN on 1 October 2011. CEN members are bound to comply with the CEN/CENELEC

9、 Internal Regulations which stipulate the conditions for giving this European 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 t

10、o any CEN member. This European Standard exists in three official versions (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 offici

11、al versions. CEN members are the national standards bodies of Austria, 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, Slova

12、kia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN 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

13、for CEN national Members. Ref. No. EN 16109:2011: EEN 16109:2011 (E) 2 Contents Page Foreword 31 Scope 42 Normative references 43 Terms and definitions .44 Sampling and sample preparation .45 Method A: Determination of phenolic hydroxyl content and 232,5 nm absorption for the identification of ligno

14、sulfonates 46 Method B: Determination of organic sulfur content for the identification of lignosulfonates 87 Expression of the results . 118 Precision 129 Test report . 13Annex A (informative) Statistical results of the inter-laboratory test . 14A.1 General . 14A.2 Test Samples . 14A.3 Inter-laborat

15、ory test procedure . 14A.4 Results and statistical interpretation 14Bibliography . 17DIN EN 16109:2012-01 EN 16109:2011 (E) 3 Foreword This document (EN 16109:2011) has been prepared by Technical Committee CEN/TC 260 “Fertilizers and liming materials”, the secretariat of which is held by DIN. This E

16、uropean Standard 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. This document has been prepared under a mandate given to CEN by

17、 the European Commission and the European Free Trade Association. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN

18、/CENELEC Internal 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, Lit

19、huania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. DIN EN 16109:2012-01 EN 16109:2011 (E) 4 1 Scope This document specifies two complementary methods (method A and method B) that allow lignosulfonates to b

20、e indentified as soluble complexing agents in fertilizers. NOTE Lignosulfonate, as a complexing agent, is a natural polymer produced as a by-product of the sulfite method for manufacturing paper from wood pulp in the paper industry. As a natural polymer, it presents a poorly defined and variable che

21、mical structure. It is an intricate mixture of small- to moderate-sized polymeric compounds with sulfonate groups attached to the molecule, and diverse complexing capacity. The methods are applicable to EC fertilizers covered by Regulation (EC) No 2003/2003 1. 2 Normative references The following re

22、ferenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 1482-2, Fertilizers and liming materials Sampling and sample p

23、reparation 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 and liming materials and soil improvers Vocabulary Part 2: Terms relating to fertilizers EN ISO 3696, Water for analytical laborato

24、ry 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 and EN 12944-2:1999 apply. 4 Sampling and sample preparation Sampling is not part of the method specified in this document. A recommende

25、d sampling method is given in EN 1482-1. Sample preparation shall be carried out in accordance with EN 1482-2. 5 Method A: Determination of phenolic hydroxyl content and 232,5 nm absorption for the identification of lignosulfonates 5.1 Principle The method for the determination of the phenolic hydro

26、xyl content is based on the ultraviolet absorption of phenols in alkaline solution (phenolate). The absorbance of an alkaline solution of the sample is measured directly against an acid solution of the same sample. The phenolic hydroxyl content of the sample is calculated from the molar extinction c

27、oefficient maximum of the resulting curve and the molar extinction coefficient of reference compounds determined in the same way. DIN EN 16109:2012-01 EN 16109:2011 (E) 5 The determination of the absorption at 232,5 nm is normally considered the method for the quantification of lignosulfonates, prov

28、iding that no other ultraviolet absorbing organic compounds are present. NOTE For additional information see 3 and 4. 5.2 Apparatus Usual laboratory equipment, glassware, and in particular the following: 5.2.1 Magnetic stirrer. 5.2.2 Balance, capable of weighing to an accuracy of 1 mg. 5.2.3 Filter

29、paper for qualitative analysis, pore size 15 m to 20 m.1 5.2.4 pH-meter, equipped with a glass electrode. 5.2.5 UV-Vis spectrophotometer, equipped with 1 cm quartz cells. 5.3 Reagents 5.3.1 General a) reagents shall be of recognized analytical grade; b) water used for the preparation of sample solut

30、ions shall conform to EN ISO 3696, grade 2 and free of organic contaminants. 5.3.2 Hydrochloric acid solution, c(HCl)= 6 mol/l. 5.3.3 Sodium hydroxide solution, c(NaOH)= 0,1 mol/l. 5.3.4 Analytical grade fine mesh strong cation exchange resin 2Styrene/DVB type, 8 % crosslinked. Hydrogen form. Functi

31、onal group: sulphonic acid. Nominal exchange capacity: 1,7 mmolc/ml. Mesh: 50 to 100. 5.4 Procedure 5.4.1 Preparation of stock solution Weigh, to the nearest 1 mg, 0,15 g to 0,20 g of the sample in a 100 ml beaker. Add 4 g of cation exchange resin (5.3.4) and about 20 ml to 25 ml of water. Allow the

32、 ion-exchange process to take place for 20 min, ensuring proper mixing by means of a magnetic stirrer. 1) Albet 412 filter paper or equivalent is an example of suitable product commercially available. This information is given for the convenience of users of this European Standard and does not const

33、itute an endorsement by CEN of this product. 2) Biorad AG 50 W-X8 (50-100) Cat. No. 142-1431 is an example of suitable product commercially available. This information is given for the convenience of users of this European Standard and does not constitute an endorsement by CEN of this product. DIN E

34、N 16109:2012-01 EN 16109:2011 (E) 6 Filter (5.2.3) into a 250 ml volumetric flask to remove the resin and thoroughly wash the filter. Dilute to the mark with water (stock solution). 5.4.2 Solution A (acid) Take an aliquot (40 5 ml) of the stock solution into a 100 ml beaker and adjust pH between 2,0

35、 and 2,2 with few drops of hydrochloric acid solution (5.3.2). Pipette 5 ml of the pH-adjusted solution into a 50 ml volumetric flask and dilute to the mark. Final concentration 0,06 g/l to 0,08 g/l. 5.4.3 Solution B (basic) Pipette 5 ml of the stock solution into a 50 ml volumetric flask. Add 10 ml

36、 of sodium hydroxide solution (5.3.3) to adjust pH over 11,0. Dilute to the mark. Final concentration 0,06 g/l to 0,08 g/l. Check that the pH of the solution is over 11,0, if not prepare solution B adding more sodium hydroxide. 5.4.4 Solution C Pipette 10 ml of the stock solution into a 100 ml beake

37、r and fill with water to 60 5 ml. Adjust the pH of the solution between 4,0 and 5,0 with the sodium hydroxide solution (5.3.3). Transfer quantitatively into a 100 ml volumetric flask, dilute to the mark with water and homogenize. See 5.4.6. 5.4.5 Measurement of phenolic hydroxyl content Fill both ce

38、lls in the UV spectrophotometer with water. Enter background correction. Scan from 340 nm to 220 nm to check baseline. Fill the sample cell with solution B (5.4.3), and the reference cell with solution A (5.4.2). Scan from 340 nm to 220 nm. Rinse cells with water. 5.4.6 Measurement of 232,5 nm absor

39、ption Fill the sample cell with solution C (5.4.4), and the reference cell with water and record absorbance at 232,5 nm. The absorbance of the final solution should be between 0,2 and 0,8 to minimize deviations from Beers Law instrumental error. If necessary, the volume to be taken from stock soluti

40、on (5.4.1) to prepare solution C (5.4.4) should be adapted. 5.5 Calculation 5.5.1 Phenolic hydroxyl content Plot the spectrum in terms of absorbance. Record wavelength and absorbance for the maximum peak at 240 nm to 260 nm and for the minimum on either the right or the left side of the maximum. Sub

41、tract minimum absorbance from the maximum height (Absmax) (see Figure 1). DIN EN 16109:2012-01 EN 16109:2011 (E) 7 Figure 1 Example of the spectrum of solution B against A for the determination of phenolic hydroxyl content of a lignosulfonate showing the maximum and the minimum (in this case at the

42、left side) absorbances Calculate the phenolic hydroxyl content, wph, of the sample, expressed as mass fraction in percent using the Absmaxvalue of the sample and an average maxvalue for reference compounds (8 867,5 lmol-1cm-1) by the following formula: 1000100117 =maxmaxphdmAbsw (1) 525050 =d (2) wh

43、ere m is the mass of the test portion in grams; d is the dilution factor included in 5.4.1, 5.4.2. and 5.4.3, in millilitres; Absmaxis the value obtained subtracting the minimum from the maximum absorbance; 17 is the number of OH mol molOHgOH17; maxis the average molar extraction coefficient for ref

44、erence compounds (8 867,5 lmol-1cm-1). 5.5.2 232,5 nm absorption as lignosulfonic acid content Calculate the 232,5 nm absorption as lignosulfonic acid content, wla, of the sample, expressed as mass fraction in percent, by the following formula: 105,232la=fmdAw (3) DIN EN 16109:2012-01 EN 16109:2011

45、(E) 8 Vd250100 = (4) where A232,5is the absorbance recorded at 232,5 nm (5.4.6); m is the mass of the test portion in grams; d is the dilution factor in millilitres considering dilutions in 5.4.1 and 5.4.4; f is the absorptivity of the lignosulfonic acid in l/g cm, f = 36,5; V is the volume in milli

46、litres used to prepare solution 5.4.4. 6 Method B: Determination of organic sulfur content for the identification of lignosulfonates 6.1 Principle Sulfur bound to the lignin backbone in lignosulfonate samples is commonly termed organic sulfur while the remaining sulfur is conveniently described as i

47、norganic sulfur (free sulfur, bisulfite addition compounds, sulfates, sulfites, sulfides, thiosulfates and tetrathionates). The method is based on the oxidation of inorganic sulfur to sulfate with alkaline iodine and its determination as barium sulfate. The remaining compounds are oxidized with a ni

48、tric-perchloric acid mixture to destroy organic matter and convert the sulfonated sulfur to sulfate, which is then determined as barium sulfate. NOTE For additional information see 5. 6.2 Apparatus Usual laboratory equipment, glassware, and in particular the following: 6.2.1 Magnetic stirrer. 6.2.2 Balance, capable of weighing to an accuracy of 0,1 mg. 6.2.3 Filter paper for qualitative analysis, pore size 15 m to 20 m.36.2.