大体积搅拌棒吸附萃取技术与热脱附-气相色谱-质谱法测定地表水中多环芳烃

Determination of polycyclic aromatic hydrocarbons in surface water using large volume stir bar sorptive extraction coupled with thermal desorption-gas chromatography-mass spectrometry

基于搅拌棒吸附萃取(SBSE)技术建立了气相色谱-质谱测定地表水中16种多环芳烃(PAHs)的分析方法。该法采用多搅拌吸附棒同时富集,依次热脱附冷聚焦后进样的方式有效解决了搅拌棒吸附时间长、富集水样体积小等问题。优化后的结果表明,在0.2~10 ng/L范围内(萘为0.5~10 ng/L范围),16种PAHs的线性关系良好,相关系数(r)均>0.99,方法检出限(MDL)为0.03~0.20 ng/L(萘为0.50 ng/L)。用该方法对钱塘江流域地表水进行测定,共检测出11种PAHs,含量为0.13~1.57 ng/L,不同添加水平下的加标回收率为75.6%~108.9%。该法可应用于地表水样品中该类物质的超痕量检测。

A fast and sensitive analytical method for the ultra trace determination of 16 kinds of polycyclic aromatic hydrocarbons (PAHs) in surface water based on stir bar sorptive extraction (SBSE) coupled with gas chromatography. mass spectrometry was established. Multiple stir bars simultaneous enrichment with sequential cryofocusing and merged injection technique was used to effectively solve the problem of long adsorption time and small sample volume with SBSE. The conditions of thermal desorption time, cryofocusing temperature of cooled injection system (CIS), CIS desorption time and extraction time were investigated. Under the optimized conditions, the results showed that the linear range was between 0.2 ng/L and 10 ng/L (naph-thalene, 0.5-10 ng/L), and the method detection limits (MDLs) of the 16 PAHs ranged from 0.03 ng/L to 0.20 ng/L (naphthalene, 0.50 ng/L). The 11 PAHs were determined in the Qian. tang River surface water samples, and the contents were between 0.13 ng/L and 1.57 ng/L. The recoveries of the 16 PAHs spiked in surface water samples at different levels were between 75.6% and 108.9%. The method can be efficiently applied to the determination of PAHs.