DIN Standards Committee Food and Agricultural Products
DIN EN 16318
Fertilizers - Determination of trace elements - Determination of chromium (VI) by photometry (method A) and by ion chromatography with spectrophotometric detection (method B); German version EN 16318:2013
Düngemittel - Bestimmung von Elementspuren - Bestimmung von Chrom (VI) mit Photometrie (Verfahren A) und mit Ionenchromatographie mit spektrometrischer Detektion (Verfahren B); Deutsche Fassung EN 16318:2013
Overview
In addition to nutrients and organic matter, heavy metals and organic pollutants may also enter the soil. In order to keep the risks as low as possible, the requirements for product quality and product safety of fertilizers have considerably increased. In the future, the requirements and official controls of fertilizers will focus on controlling heavy metal contents (risk aspect) not only on the national level but also within the European market and, as a result, make an important contribution to the environmental and consumer protection. Validated analytical techniques are the basis of comparable controls. The European Standards EN 16318 and EN 16319 have been prepared within the framework of Mandate M/418 given to CEN by the European Commission and the European Free Trade Association. EN 16318 contains two methods for the determination of the content of soluble chromium (VI) (chromate) in fertilizers. Method A specifies the determination of chromate after extraction with water by photometry. This method can be used to determine chromium(VI)-mass fractions in solids higher than 1 mg/kg. Method B specifies the determination of chromate by alkaline digestion and ion chromatography with spectrophotometric detection. This method can be used to determine chromium(VI)-mass fractions in solids higher than 0,1 mg/kg. In case of reducing or oxidizing fertilizer matrix, no valid chromium(VI) content can be reported. As a result, no chromium(VI) could be detected during various inter-laboratory tests using different samples. Therefore, CEN/TC 260 decided to include the statistical data from an inter-laboratory test performed by the expert group "Fertilizers" of the Verband landwirtschaftlicher Untersuchungs- und Forschungsanstalten (VDLUFA) (Association of German Agricultural Investigation and Research Institutions) in informative Annex A. Simultaneously, further analyses using method B with spiked samples were performed, the results of which were included in informative Annex B. EN 16319 contains a method for the determination of the content of cadmium, chromium, nickel and lead in fertilizers and liming materials using inductively coupled plasma-atomic emission spectrometry (ICP-AES) after aqua regia dissolution. Limits of quantification are dependent on the sample matrix as well as on the instrument, but can roughly be expected to be 0,3 mg/kg for Cd and 1 mg/kg for Cr, Ni and Pb. The method has been validated during inter-laboratory tests at European level, with the participation of 19 laboratories. The statistical results are stated in informative Annex A. Following the requirements of Mandate M/418, the methods have been published as Technical Specifications for the time being. After the relevant resolution of CEN/TC 260 the Technical Specifications have been adopted as European Standards within the framework of the Unique Acceptance Procedure (UAP). The documents have been prepared in CEN/TC 260 "Fertilizers and liming materials" (secretariat: DIN, Germany) with intensive German collaboration, in particular with technical assistance of the VDLUFA. National mirroring took place at Working Committee NA 057-03-02 AA "Düngemittel" ("Fertilizers") of the NAL.
