自动索氏抽提-凝胶渗透色谱(GPC)-气相色谱/质谱法测定沉积物中多环芳烃和有机氯农药

Determination of PAHs and OCPs in sediments by gas chromatography/mass spectrometry with automatic soxhlet extraction and GPC

采用自动索氏抽提-凝胶渗透色谱(GPC)-气相色谱/质谱技术,建立了沉积物中多环芳烃和有机氯农药的检测方法.通过对自动索氏抽提提取条件、凝胶渗透色谱净化条件进行优化.以丙酮∶正己烷(V∶V=1∶1)作为提取溶剂,提取温度160℃,用乙酸乙酯∶环己烷(V∶V=1∶1)定容至40 mL,转移上GPC.GPC在线浓缩系统真空腔真空度为180 mbar/190 mbar,以乙酸乙酯∶环己烷(V∶V=1∶1)为流动相,流速为5 mL·min-1,并采用气相色谱-质谱法定性和定量分析.在优化条件下,16种多环芳烃和19种有机氯农药在10—1000μg·L-1范围内具有良好的线性关系(R2>0.99),检出限(S/N=3)为0.008—0.353μg·kg-1.加标水平为10、50、100μg·kg-1时,平均加标回收率分别为77.6%—106.1%、79.9%—108.7%和80.6%—107.8%,相对标准偏差(RSDs,n=5)均小于10%.

A method for determination of trace amount of PAHs and OCPs in sediments by gas chromato-graphy/mass spectrometry with automatic Soxhlet extraction combined GPC was developed. The procedures of extraction and purification, as well as chromatographic and mass spectrometric parameters, were optimized. The samples were extracted by Soxhlet extraction with acetone： hexane （ V： V = 1 ： 1 ） at 160 ~C, and with cyclohexane ： ethyl acetate （ V： V = 1 ： 1 ） the capacity to 40 mL after injecting into GPC column with cyclohexane ： ethyl acetate （ V： V = 1 ： 1 ） as the mobile phase at a flow rate of 5 mL. min-1 and GPC vacuum was 180 mbar/190 mbar. The fraction among 1020--3260 s was collected for subsequent analysis. The analysis of target compounds was performed by gas chromatography-mass spectrometry （GC-MS）. Under the optimized conditions, the calibration curves of 16 PAHs and 19 OCPs were linear in the range of 10---10（30μg.L -1 with correlation coefficients （R2 〉 0.99 ） and limits of detection of 0. 008-0. 353 μg. kg- 1. The average spiked recoveries for the samples products at the spiked levels of 10, 50 and 100 μg.kg-1 were in the range of 77. 6%--106.1% ,79.9%--108.7% and 80.6%--107.8%,respectively,and relative standard deviations （ RSD, n = 5 ） less automatic, rapid, accurate, sensitive and reliable, persistent organic pollutants（POPs） in sediments.