Rapid simultaneous determination of herbicides in human serum by UPLC-ESI-MS
A simple, rapid and reliable method was developed for multi-class and multi-residue analysis of herbicides in human serum by ultra-performance, liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS). Serum sample preparation was carried out by one-step protein precipitation and analytes extraction using acetonitrile. After centrifugation, an aliquot of 5 μL of supernatant was injected into a C18 column for the separation of 22 kinds of triazine and phenylurea herbicides using gradient program with water–acetonitrile as the mobile phase and the separation of 29 kinds of herbicides using gradient program with 5 mM ammonium acetate aqueous solution containing 0.1% v/v formic acid–acetonitrile as the mobile phase. An excellent linearity of most herbicides was observed from 0.1 μg L−1 up to 10.0 μg L−1. The limits of detection (LODs) in serum ranged from 0.03 to 6.00 μg L−1, and the limits of quantification (LOQs) ranged from 0.10 to 18.0 μg L−1. Intra- and inter-day precisions at three spiked levels were satisfactory for the 51 herbicides with the RSD of 1.02–10.0% and 1.09–12.0%, respectively. Extraction recoveries of 51 herbicides were satisfactory and ranged from 63.6% to 109% at the three spiked levels with RSDs of 1.06% to 12.0%. This UPLC-ESI-MS method is simple, accurate, and useful for multi-class multi-residue determination of herbicides and benefits clinical analysis and diagnosis.