加速溶剂萃取-凝胶渗透色谱-气相色谱-质谱法同时测定水产品中短链及中链氯化石蜡

Simultaneous determination of short and medium chain chlorinated paraffins in aquatic products by accelerated solvent extraction-gel permeation chromatography-gas chromatography mass spectrometry

目的建立加速溶剂萃取-凝胶渗透色谱-气相色谱-电子捕获负化学源-低分辨质谱法同时测定水产品中短链氯化石蜡(short chain chlorinated paraffins,SCCPs)和中链氯化石蜡(medium chain chlorinated paraffins,MCCPs)的分析方法。方法水产品样品经冷冻干燥后,加入适量硅藻土混合并研磨均匀,以二氯甲烷/正己烷(1:1,V:V)对目标物进行萃取(100℃、1500 psi),收集凝胶渗透色谱仪9~21 min馏出液,浓缩定容后上机。结果采用气相色谱-电子捕获负化学源-低分辨质谱法测定水产品中SCCPs和MCCPs,方法检出限分别为16.2ng/g(n=7)和17.9ng/g(n=7),低(50ng/g)、中(100ng/g)、高(500ng/g)3个水平的加标回收率为80.8%~95.2%,相对标准偏差为4.53%~8.48%。采用该方法对采集的不同水产品样品进行分析,样品中SCCPs和MCCPs检出率为69.7%和63.6%,检出含量分别为24.7~2632.0ng/gdw和3.88~360.00ng/gdw。SCCPs和MCCPs在不同水产品中的分布模式相似,碳原子同族体SCCPs以C_(10)和C_(11)为主,MCCPs以C_(14)和C_(15)为主,氯原子同族体以Cl_(5)~Cl_(7)为主。结论本研究建立的方法灵敏度高、重现性好且自动化程度高,可有效提升检测效率,适用于水产品中短链和中链氯化石蜡的检测。

Objective To establish an analytical method for the simultaneous determination of short chain chlorinated paraffins(SCCPs)and medium chain chlorinated paraffins(MCCPs)in aquatic products by accelerated solvent extraction-gel permeation chromatography-gas chromatography-electron capture negative ion-low resolution mass spectrometry.Methods The aquatic product samples were freeze-dried,and then appropriate amount of diatomaceous earth was added into them for mixing,and then the targets were extracted by dichloromethane/n-hexane(1:1,V:V)at 100℃and 1500 psi,and then the gel permeation chromatograph fractions were collected for 9-21 min,and then concentrated and fixed on the machine.Results The limits of detection of SCCPs and MCCPs in aquatic products by gas chromatography-electron capture negative chemical source-low resolution mass spectrometry were 16.2 ng/g(n=7)and 17.9 ng/g(n=7),respectively,and the spiked recoveries of the 3 levels,i.e.,low(50 ng/g),medium(100 ng/g),and high(500 ng/g),were in the range of 80.8%-95.2%,and the relative standard deviations ranged from 4.53%to 8.48%.Different aquatic samples collected were analysed by this method,and the detection rates of SCCPs and MCCPs in the samples were 69.7%and 63.6%,with the detection levels ranging from 24.7 to 2632.0 ng/g dw and from 3.88 to 360.00 ng/g dw,respectively.The distribution patterns of SCCPs and MCCPs in different aquatic products were similar,with the carbon homologues SCCPs dominated by C_(10)and C_(11),MCCPs dominated by C_(14)and C_(15),and the chloride homologues dominated by Cl_(5)-Cl_(7).Conclusion The method established in this study has high sensitivity,good reproducibility and high degree of automation,which can effectively improve the detection efficiency,and is suitable for the detection of SCCPs and MCCPs in aquatic products.