气相色谱-质谱法同时测定三文鱼中12种多氯联苯含量

摘要

目的：建立气相色谱-质谱法(gas chromatography-mass spectrometry, GC-MS)同时测定三文鱼中12种多氯联苯的方法。方法样品经石油醚提取后,用浓硫酸和层析柱进行净化,正己烷洗脱。得到的提取物经DB-5MS色谱柱(30 m×250μm,0.25μm)分离,载气为氦气,流速为1.5 mL/min,温度为270℃。然后采用电子轰击离子源进行质谱测定,全扫描方式采集数据。结果12种多氯联苯在10.0~1000μg/L浓度范围内呈良好的线性关系,相关系数r＞0.9989,方法检出限为0.3~1.2μg/kg,3个不同加标水平下PCBs的平均回收率为85.5%~99.6%,日内相对标准偏差在3.56%~8.12%范围内。结论该方法灵敏度高、准确度和精密度良好,适用于三文鱼中12种PCBs含量的快速检测。%Objective Toestablish a method for simultaneous determination of 12 kinds of polychlorinated biphenyls (PCBs) in salmon by gas chromatography-mass spectrometry (GC-MS).MethodsThesalmon samples were extracted with petroleum ether, then purified by concentrated sulfuric acid and chromatographic column, followed by elution with n-hexane. After being separated by DB-5MS chromatographic column (30 m×250μm, 0.25μm) with helium as carrier gas, the flow rate of 1.5 mL/min, and the temperature of 270℃, the extractive was detected by mass spectrometry with electron impact ion source. The data were collected by full scan mode.Results The calibration curves of 12 kinds of PCBs showed good linearities when the concentrations range from 10.0μg/L to 1000μg/L, and the correlation coefficients (r) were all larger than 0.9989. The limits of detection (LODs) of the method were 0.3μg/kg to 1.2μg/kg, the average recoveries of PCBs at 3 different standard addition levels were 85.5% to 99.6%, and the intra-day relative standard deviations (RSDs) were 3.56% to 8.12%.ConclusionThis method is sensitive, accurate and repeatable, which is suitable for the rapid determination of 12 kin ds of PCBs in salmon.