Simultaneous Determination of Residues of Five Banned Amides in Leather and Leather Products by Gas Chromatography-Tandem Mass Spectrometry Combined with Microwave-assisted Extraction

An effective method was established for the simultaneous determination of residues of five banned amides in leather and leather products. Residual banned amides in leather and leather products were microwave-assistedly extracted using methanol as extraction solvent. The extract was then purified with solid-phase extraction( SPE) column,followed by the analysis of gas chromatography-tandem mass spectrometry( GC- MS/MS). The concentration of each analyte was calibrated by the external standard method. The limits of quantitation( LOQ,S/N = 10) were 20,10,1,20,3μg /kg for formamide,N-methylformamide,N,N-dimethylformamide,N-methylacetamide and N,N-dimethylacetamide,respectively. The average recoveries varied from 81. 4% to 86. 9% at three spiked concentration levels,with relative standard deviations( RSD) of 4. 5%- 8. 7%. The proposed method was simple,rapid,accurate and sensitive,and the limits of quantitation( LOQ) were much less than the limited requirement for regulation concerning registration,evaluation,authorization and restriction of chemicals( REACH). The method could satisfy completely the demand of determination of residual banned amides in leather and leather products.