同位素稀释结合气相色谱-串联二级质谱法测定PM2.5中12种硝基多环芳烃

Determination of 12 nitro-polycyclic aromatic hydrocarbons in PM2.5 by isotope dilution combined with gas chromatography-stage 2 tandem mass

目的采用同位素稀释结合气相色谱-串联二级质谱技术,建立空气PM2.5中12种硝基多环芳烃检测方法。方法空气PM2.5经石英滤纸采集,剪碎后放入烧杯,加50μl同位素内标溶液,待测物分别用60 ml二氯甲烷超声提取2次,再用40 ml丙酮超声提取1次,合并提取液,提取液经旋转蒸发仪浓缩至1.0 ml;经中性硅胶柱净化,收集洗脱液再浓缩至1.0 ml,用气相色谱-串联二级质谱法测定。结果2-硝基联苯、2-硝基芴检出限均为2 ng/ml,最低检出浓度为1 pg/m^(3);5-硝基苊、3-硝基蒽的检出限均为2 ng/ml,最低检出浓度为2 pg/m^(3),其他化合物的检出限均为5 ng/ml,最低检出浓度为5 pg/m^(3)(采样体积均以1500 m^(3)计)。12种硝基多环芳烃的加标回收率为73.4%~119.6%,相对标准偏差(RSD)为1.4%~18.2%。结论该方法适用于PM2.5中12种硝基多环芳烃的测定。

Objective To establish a method for the determination of three nitro-polycyclic aromatic hydrocarbons by Isotope dilution combined with gas chromatography-tandem mass in PM2.5.Methods PM2.5 was collected by quartz filter paper,which was cut into pieces,put into a beaker,and added with 50μl isotope internal standard solution.The samples to be tested were ultrasonically extracted twice with 60 ml methylene chloride,and once with 40 ml acetone.The extracts were combined,and the extracts were concentrated to 1.0 ml by rotary evaporation instrument.After purification by neutral silica gel column,the eluent was collected and then concentrated to 1.0 ml.The eluent was determined by gas chromatography coupled with tandem secondary mass spectrometry.Results The detection limits of 2-nitrobiphenyl and 2-nitrofluorene were both2 ng/ml,the minimum detected concentration was 1 pg/m^(3).The detection limits of 5-nitroacenaphthene and 3-nitrophenanthrene were 2 ng/ml,and the minimum detected concentrations were 2 pg/m^(3).The detection limits of the other substance were5 ng/ml,the minimum detected concentrations were 5 pg/m^(3)(1500 m^(3)).The recoveries of nitro-polycyclic aromatic hydrocarbons were within 73.4%-119.6%,and the relative standard deviations(RSDs)were within 1.4%-18.2%.Conclusion The method is suitable for the determination of nitro-polycyclic aromatic hydrocarbons in PM2.5.