BS EN 16962:2018 pdf download

BS EN 16962:2018 pdf download.Fertilizers – Extraction of water soluble micro- nutrients in fertilizers and removal of organic compounds from fertilizer extracts
1 Scope
This European Standard specifies a method for the extraction of water soluble forms of boron, cobalt,copper, iron, manganese, molybdenum and zinc from mineral fertilizers containing one or more micro- nutrients and the procedure for removal of organic compounds from the water extracts.
The extracts can be analysed according to EN 16963, EN 16965, prEN 17041, prEN 17042, prEN 17043 and CEN/TS 17060.
2 Normative references
The following documents in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN 12944-1, Fertilizers and liming materials and soil improvers一Vocabulary 一Part 1: General terms
EN 12944-2, Fertilizers and liming materials and soil improvers一Vocabulary 一Part 2: Terms relating to fertilizers
EN 16963, Fertilizers 一Determination of boron, cobalt, copper, iron, manganese, molybdenum and zinc using ICP-AES
EN 16965, Fertilizers一Determination of cobalt, copper, iron, manganese and zinc using flame atomic absorption spectrometry (FAAS)
prEN 17043, Fertilizers – – Determination of molybdenum in concentrations≤10 % using spectrometry of a complex with ammonium thiocyanate
EN ISO 3696, Water for analytical laboratory use一Specification and test methods (ISO 3696)
8.2 Extraction
Close the vessel tightly and shake vigorously by hand to disperse the sample. Then place the vessel on the shaker [7.1) and shake for 60 min. The intensity of shaking shall be adjusted to prevent any settling of the sample during the extraction. The temperature of the extraction solution shall be kept at (20土2] °C during the whole extraction time. Filter the extract if necessary immediately after the extraction into a plastic vessel. Use ash-free filter paper of recognized and tested quality [7.4) and discard the first portion of the filtrate (approximately 20 ml). Pipette 20 ml of the extract into a 25 ml volumetric flask, add 2,5 ml of diluted nitric acid solution [6.2.1], fill to the mark with water (6.1) and mix well. The final concentration of nitric acid is 0,5 mol/l. Account shall be taken of this dilution when taking aliquot portions and calculating the percentage of micro-nutrient in the sample. Prepare a blank test solution following the same procedure as for samples. Acidification of the water extract with nitric acid is not suitable for spectrophotometric determination of molybdenum according to prEN 17043. In this case hydrochloric acid (6.4) shall be added; the final concentration of hydrochloric acid is 0,5 mol/l. Acidification with hydrochloric acid shall be used also if precipitation of Fe([II] is observed after the addition of nitric acid. If boron is not to be determined standard glassware may be used. If the measurement is not carried out immediately the acidified extracts may be stored in tightly closed plastic vessels for up to 15 days.