超高效液相色谱-串联质谱法测定环境样品中溴嘧氯草醚残留及其在土壤中降解特性的研究

建立了超高效液相色谱-串联质谱法(UPLC-MS/MS)测定土壤、沉积物和水中溴嘧氯草醚残留量的方法,研究了溴嘧氯草醚在3种不同类型土壤中的降解特性.样品经乙腈提取后,以C18固相萃取柱净化,采用梯度洗脱程序、BEH C18色谱分离柱、应用UPLC-MS/MS多反应监测模式测定溴嘧氯草醚.对0.005、0.05和2.0 mg/kg添加浓度样品进行回收实验,溴嘧氯草醚在土壤、沉积物和水中的平均回收率为87%~106%,变异系数为2.8%~8.0%.溴嘧氯草醚在0.5~20μg/L浓度范围内相关系数R2>0.9999,溴嘧氯草醚在土壤(沉积物)和水中的定量限分别为0.2μg/kg和0.2μg/L.应用建立的溴嘧氯草醚残留分析方法检测了土壤降解样品,结果表明,溴嘧氯草醚在3种不同土壤中好氧降解的半衰期为1.72~28.2 d,厌氧降解的半衰期为2.93~31.4 d;在同一种土壤样品中,好氧条件下溴嘧氯草醚降解快于厌氧条件;土壤中溴嘧氯草醚降解的快慢与土壤的pH值、阳离子交换量和土壤质地有关.

Residue Analysis of SIOC0426 in Environmental Samples and Its Degradation in Soil

An analytical method based on ultra performance liquid chromatography-tandem mass spectrometry was developed for the determination of SIOC0426 residues in environment samples ( soil, sediment and water) . The fate of SIOC0426 in three kinds of soils was also evaluated. The target compound was extracted with acetonitrile, cleaned up by C18 cartridge, and analyzed by gradient ultra performance liquid chromatography-tandem mass spectrometry with electrospray ionization under positive mode ( ESI+) using a UPLC BEH C18 column. The method was validated using fortified soil, sediment and water. Mean recoveries of SIOC0426 at three spiked levels ( 0 . 005 , 0 . 05 and 2 . 0 mg/kg ) ranged from 87% to 106% with relative standard deviations of 2. 8%-8. 0%. Limits of quantification ( LOQs) of SIOC0426 in soil ( sediment) and water were 0. 2 μg/kg and 0. 2 μg/L, respectively. Linear calibration functions with correlation coefficients R2>0. 9999 were obtained in the concentration range of 0. 5-20 μg/L. This method was applied to the analysis of SIOC0426 residues in soil degradation samples. The results showed that the half-life of SIOC0426 ranged from 1. 72 days to 28. 2 days in three kinds of soils under aerobiotic conditions. While, the half-life of SIOC0426 ranged from 2. 93 days to 31. 4 days in three kinds of soils under anaerobic conditions. The degradation speed of SIOC0426 under aerobiotic conditions was faster than that under anaerobic conditions in the same soil. And the degradation speed of SIOC0426 in soils may be connected with the pH value of soils, cation exchange capacity and soil texture.