QuEChERS-液相色谱-串联质谱法测定稻田中土壤及水稻中抗生素的残留量

Determination of antibiotic residues in soil and rice of the simulated paddy field by QUECHERS-LC-MS/MS

采用QuEChERS-LC-MS/MS法建立了稻田模拟系统中残留的4种目标抗生素的检测方法。样品经5%甲酸-乙腈提取,用内标法进行定量。结果表明,4种目标抗生素在0.10~100μg·L^(−1)内具有良好的线性关系(R 2>0.998)。OFX、SMZ、ROX和TET的检出限分别为0.10、0.10、0.05、0.20μg·L^(−1)。4种目标物质在稻田水、稻米、水稻植株(地上部分和地下部分)和稻田土壤中的回收率分别为82.8%~166.1%、78.1%~103.5%、94.5%~97.8%、67.7%~100.2%、86.7%~93.9%,相对标准偏差分别为0.3%~8.3%、1.4%~3.8%、1.1%~6.8%和1.1%~2.4%。通过建立稻田模拟系统,长期用含相应质量浓度抗生素的污水灌溉,对稻田模拟系统中抗生素的残留进行了检测。检测结果表明,SMT和ROX在各基质中均有检出,检出质量浓度为0~250.908μg·kg^(−1)。OFX和TET在稻米样品中未检出,但在其余基质中均有检出,检出质量浓度为0~272.354μg·kg^(−1)。

A method was developed for the determination of four target antibiotics residual in the rice field simulation system by liquid chromatography-tandem mass spectrometry(LC-MS/MS)coupled with QuEChERS.By optimizing the pretreatment conditions,5%formic acid-acetonitrile was used to extract the antibiotics in each matrix,and the internal standard method was used to quantization detection.The results show that the four target antibiotics had a good linear relationship in the range of 0.1—100μg·L^(−1)(R 2>0.998).The limits of detection(LOD)of ofloxacin(OFX),sulfamethoxazole(SMZ),roxithromycin(ROX)and tetracycline(TET)were 0.10,0.10,0.05 and 0.20μg·L^(−1),respectively.The average recoveries of the four target compounds in paddy water,rice flour,rice plants(aboveground and underground parts)and paddy soil were 82.8%—166.1%,78.1%—103.5%,94.5%—97.8%,67.7%—100.2%,86.7%—93.9%,respectively,with relative standard deviations(RSD,n=6)of 0.3%—8.3%,1.4%—13.8%,1.1%—6.8%and 1.1%—2.4%,respectively.A paddy field simulation system was established and irrigated for a long-term by the simulated wastewater containing antibiotics with the corresponding mass concentration.The antibiotic residues in the paddy field simulation system were detected.SMT and ROX were detected in each matrix,and the detected mass concentration was 0-250.908μg·L^(−1).OFX and TET were not detected in rice flour,but were detected in all other matrices,and the detected mass concentration was 0-272.354μg·L^(−1).