全二维气相色谱-飞行时间质谱测定地下水中低环多环芳烃及其衍生物

Determination of Low-ring PAHs and Their Derivatives in Groundwater by GC × GC-TOF MS

建立了地下水中低环多环芳烃及其衍生物的全二维气相色谱-飞行时间质谱(GC×GC-TOF MS)检测方法。对比研究了液液萃取(LLE)和固相萃取(SPE)对地下水中低环多环芳烃及其衍生物的提取效率,优选液液萃取为前处理方法。在优化条件下,除1,2,3,4-四氢萘(r=0.987 2)和联苯(r=0.989 9)外,其它目标物在0.1~1 000μg/L范围内具有良好的线性关系,相关系数(r)均大于0.99。地下水的平均加标回收率为63.3%~111%,除喹啉的相对标准偏差(RSD,n=6)为24.9%外,其余目标物的RSD均小于9.5%,方法检出限在1.63~14.7 ng/L之间。该方法用于河北地区6个地下水样中低环多环芳烃及其衍生物的检测,4个样品有检出,最高浓度达353 ng/L。

A method was developed for the determination of low-ring polycyclic aromatic hydrocarbons （PAHs） and their derivatives in groundwater by liquid - liquid extraction （ LLE ） followed by comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry （ GC× GC - TOF MS ）. Compared with solid phase extraction （ SPE ）, liquid - liquid extraction （ LLE ） shows higher extraction recoveries for samples, thus LLE was selected as the sample pretreatment method. The optimized results showed that the method has a good linear range of 0. 1 - 1 000μg/L with the correlation coefficients （r） higher than 0.99 for most of the targets, except for 1, 2, 3, 4-tetrahydronaphthalene （r = 0. 987 2 ） and biphenyl （ r = 0. 989 9 ）. The spiked recoveries of the targets ranged from 63.3% to 111% with relative standard deviations less than 9.5% （RSD, n = 6）, except for quinoline（ RSD, 24.9% ）, and the detection limits ranged from 1.63 ng/L to 14. 7 ng/L. The method was applied in the determination of low-ring PAHs and their derivatives in real groundwater samples from Hebei province, and the pollutants in two - thirds of samples were detected with the maximum concentration of 353 ng/L.