Determination of triazole fungicide and triazine herbicide residues in Chinese herbs by ultra-performance liquid chromatography-tandem mass spectrometry

Abstract

A method using QuEChERS clean-up followed by UPLC-MS/MS has been established for the quantitative determination of the residues of 10 triazole fungicides and 18 triazine herbicides in Chinese herbs including Radix Glycyrrhizae, Radix Panacis Quinquefolii, Salvia miltiorrhiza, Radix Notoginseng and Panax ginseng C. The pesticide residues were extracted from the samples by acetonitrile containing 1% (v/v) acetic acid, cleaned-up with primary secondary amine (PSA) and then analyzed using UPLC-MS/MS in multiple reaction monitoring (MRM) mode with positive electrospray ionization. The analytical column was Shim-pack XR-ODS II (75 mm x 2.0 mm) and the mobile phases were water containing 0.05% (v/v) formic acid and acetonitrile in gradient elution. The limits of quantification (S/N > or = 10) of the 28 pesticides were 0. 20 - 5.52 micro g/kg and the limits of detection ( S/N > or = 3 ) were 0.10 - 2.57 micro g/kg. All of the pesticides had good linear responses with r > or =0.999 and the average recoveries of the pesticides spiked in the Chinese herbs ranged from 70.6% - 125.7% with the RSDs of 0.7% - 14.2%. The results demonstrated that the method is simple, fast and sensitive to meet the requirements for the triazole fungicide and triazine herbicide residues and can be used for the analysis of the 28 pesticides in the above five Chinese herbs.