【摘要】 建立了高效液相色谱/质谱法(HPLC-MS)同时检测土壤中10种磺酰脲类除草剂多残留量的方法。样品在磷酸缓冲液(pH值7.8):甲醇(8∶2,V/V)中经超声波萃取,提取液直接经固相萃取小柱净化,采用HPLC-ESI(+)-MS进行定性定量分析。比较了C leanert C18,C leannertHXN和Oasis HLB 3种SPE商品柱的净化效果,结果表明C leanert C18和C leannertHXN柱的净化效果和回收率均较好。10种磺酰脲类农药的液相色谱分离在乙腈-甲醇-水(0.2%冰醋酸)梯度洗脱下完成,10个化合物的保留时间在10~16 m in。10种磺酰脲类除草剂在0.1~10.0 mg/L范围内线性良好,相关系数均在0.9964~0.9989之间;相对标准偏差在0.99%~4.26%之间。在0.01~1.0 mg/kg添加水平范围内,平均添加回收率在80.2%~104.5%之间(除苯磺隆)。本方法中10种磺酰脲类除草剂在土壤中的检出限为0.6~3.5μg/kg之间。更多还原

【Abstract】 A multi-residue method has been developed for the confirmation and quantitation of ten sulfonlylurea herbicides including nicosulfuron,thifensulfuron-methyl,metsulfuron-methyl,sulfometuron-methyl,chlorsulfuron,ethametsulfuron-methyl,tribenuron,bensulfuron-methyl,pyrazosulfuron-ethyl and chlorimuron-ethyl in soil.Samples were extracted from soil with methanol-phosphate buffer（2∶8,V/V）（pH 7.8） under ultrasonic bath.Then the extracts were brought to pH 2.5 with 85% H₃PO₄ and passed under vacuum through a solid-phase cartridge.Different types of sorbents were evaluated: silla-based Cleanert C₁₈ and two polymeric sorbents,namely Oasis HLB and Cleanert HXN.The best results were obtained with Cleanert C₁₈,and was performed by high performance liquid chromatography（HPLC）-electrospray mass spectrometry（LC-ESI-MS） instrumentation equipped with ion trap mass filter.The HPLC column used was a 4.6 mm×250 mm XDB C₁₈ column,5 μm particle size.The mobile phase was acetonitrile-methanol-0.2% acetic acid.The elution gradient was as follows: the mobile phase started with 10% of acetonitrile and 10% methanol,which was increased linearly to 45% in 14 min,to 48% in the next（2 min） and then returned to initial conditions in（2 min）.The column was equilibrated for 5 min.The column temperature was kept at 30℃ and flow rate was 1.0 mL/min.The retention times of 10 herbicides were between（10-16） min.The ten sulfonylurea compounds above mentioned were measured in fortified soil at（0.01-1.0） mg/kg levels.Average recoveries were in the range of（80.2%-104.5%） with relative standard deviations（RSDs） of（0.02%-14.9%）. The limit of detection（LOD） was 0.6-3.5 μg/kg.更多还原