气相色谱-质谱法测定渔业水质中8种除草剂的残留量

Determination of Eight Herbicides in Fishery Water by Gas Chromatography-Mass Spectrometry

本研究建立了测定渔业水质中氟乐灵、二甲戊灵、甲草胺、乙草胺、丁草胺、西玛津、莠去津、扑草净8种除草剂残留量的气相色谱-质谱法。样品用氯化钠调节盐度至20-30,二氯甲烷提取,无水硫酸钠除水,过弗罗里硅土固相萃取小柱净化,利用气相色谱-质谱法,以选择离子监测模式检测,外标法进行定量分析。采用基质匹配标准溶液校准法,8种除草剂在0.010-1.000μg/L范围内线性良好,R2均大于0.990;方法检出限以信噪比≥3估算,检出限分别为:氟乐灵0.022μg/L、西玛津0.031μg/L、莠去津0.028μg/L、乙草胺0.038μg/L、甲草胺0.041μg/L、扑草净0.035μg/L、二甲戊灵0.025μg/L、丁草胺0.020μg/L。选择0.05、0.5和2.0μg/L 3个不同浓度水平做加标回收,平均回收率为74.7%-97.7%,相对标准偏差在12.0%以内。方法检出限分别为:氟乐灵0.022μg/L、西玛津0.031μg/L、莠去津0.028μg/L、乙草胺0.038μg/L、甲草胺0.041μg/L、扑草净0.035μg/L、二甲戊灵0.025μg/L、丁草胺0.020μg/L,最低定量限均为0.05μg/L。该方法具有操作简便、准确性好、灵敏度高、重现性好等优点,可为渔业水质中这8种除草剂残留的监测提供技术支持。

To measure herbicides residues in fishery water,gas chromatography-mass spectrometry was developed to determine trifluralin,pendimethalin,alachlor,acetochlor,butachlor,simazine,atrazine,and prometryn.The samples were adjusted to salinity 20-30 with Na Cl,extracted by dichloromethane,and cleaned up with Florisil solid phase extraction（SPE） column.The analytes were detected by gas chromatography-mass spectrometry under the selected reaction monitoring mode and quantified by external standard method.The peak area was linear to the concentration of eight herbicides residues（0.010-1.000 μg/L）,and the correlation coefficients（R2） were all more than 0.990.According to S/N≥3,the detection limit of rifluralin,simazine,atrazine,acetochlor,alachlor,prometryn,pendimethalin,and butachlo were 0.022,0.031,0.028,0.038,0.041,0.035,0.025,and 0.020 μg/L,respectivly.The limit of quantification was 0.05 μg/L for all eight herbicides based on the actual samples spiked recoveries between 70% and 120%,S/N≥10,and the relative standard deviation≤15%.The average recovery of the eight herbicides fortified in different negative samples at 0.05,0.5,and 2.0 μg/L were in the range of 74.7%-97.7%,and the relative standard deviations were less than 12.00%.These results indicated that the method has the advantage of simplicity,sensitivity and repeatability,which could provide technical support for the detection of these eight herbicides residues in fishery water.