DIN EN 16162:2012-06

DIN EN 16162 specifies a method for the determination of decoquinate. This high-performance liquid chromatographic (HPLC) method with fluorescence detection is applicable to the quantification of decoquinate content in complete and complementary compound feeds, medicated feeds, semi-liquid feeds, premixtures and feed additives. The method was fully validated from LOQ to 60 000 mg/kg on different matrices during an international collaborative study, especially on complete compound feeds for poultry, at trace contamination level of 3 mg/kg and at European authorized level of 20 mg/kg to 40 mg/kg. The limit of detection is between 0,1 mg/kg and 0,3 mg/kg and the limit of quantification is around 0,5 mg/kg. These limits were validated during the collaborative study from results on the blank feed. Lower limits of detection or quantification could be reached but a single laboratory validation is then requested. Decoquinate is extracted from samples with a solution of 1 % calcium chloride in methanol using mechanical shaking or stirring for 60 min. After centrifugation or filtration, an aliquot is, if necessary, diluted with the extraction solvent and analysed by reversed phase HPLC with fluorescence detection. Positive trace level samples should be confirmed by HPLC analysis using an alternate excitation wavelength. The European Standard has been prepared by CEN/TC 327 "Animal feeding stuffs - Methods of sampling and analysis", the secretariat of which is held by NEN (Netherlands). The collaboration of DIN for the field of responsibility of CEN/TC 327 is performed through the national mirror committee, Working Committee NA 057-03-03 AA "Futtermittel" ("Animal feeding stuffs") at NAL.