液相色谱串联质谱联用法检验TNT

Determination of TNT by High-performance Liquid ChromatographyTandem Mass Spectrometry

目的建立液相色谱串联质谱联用仪检验浮土中TNT的方法。方法本文以乙腈作为溶剂提取浮土中的TNT;用Waters Xbrige C18液相色谱柱(5μm,100 mm×2.1 mm),流动相为甲醇?水=65?35进行样品分离;在APCI源负离子模式下,以m/z226.9/209.9作为定量离子对、m/z226.9/197.0作为定性离子对,用三重四级杆串联质谱进行多反应监测(MRM)分析。结果在ESI源下,TNT的电离效率相对APCI源较低,浮土中TNT的定量限为1ng/g。该方法检测TNT的线性范围为0.05~100 ng/g,相关系数为0.9991,定量下限为0.05 ng/g,加标回收率为88.5%~96.1%,浮土样品采用乙腈提取的基质效应为93.7%。结论本方法操作简单、提取方便,有效避免了尘土复杂基质的干扰,结果准确可靠,灵敏度高,满足对爆炸残留物中TNT的检测要求。

Objective To establish a HPLC-MS/MS method was to for detecting TNT in surface soil. Method The liquidliquid extraction method was used to extract the analytes. The extraction solvents and mobile phase were optimized, together with both the atmospheric-pressure chemical ionization （APCI） interface and electrospray ionization （ESI） interface for quantitative analysis. The determination was performed by triple quadrupole mass spectrometry operated with a negative APCI interface in the multiple reaction monitoring （MRM） mode. The mass-to-charge ratio （re^z） of 226.9/209.9 was found as the quantification ion pair and m/z 226.9/197.0 as the confirmation ion pair. Acetonitrile was selected as the extraction solvent. The separation was performed on a Waters Xbrige C^8 column （5 ~tm,100 minx2.1 ram） run with the mixture of methanol and water （65：35） as the mobile phase. Results The ionization efficiency in ESI mode was lower than that in APCI mode. The limit of detection was 0.05ng/g in ESI mode for TNT in surface soil, and the limit of quantitation was 0.05 ng/g. High recovery （88.5 % - 96.1%） was achieved. Good linearity （R=0.9991） was obtained at the concentration among 0.05-100 ng/g. Matrix effect was 93.7 % of liquid-liquid extraction with acetonitrile. Conclusion This method is simple, accurate and sensitive, able to be used for trace TNT detection in explosive residues.