冷冻研磨超声浸提分离-气相色谱-质谱法测定充油丁苯橡胶中8种多环芳烃的含量

GC-MS Determination of 8 Polycyclic Aromatic Hydrocarbons in Styrene Butadiene Rubber with Separation by Freeze-Grinding and Ultrasonic Extraction

为从充油丁苯橡胶样品中分离提取其中所含8种多环芳烃化合物(PAHs,包括苯并[a]蒽、艹屈、苯并[b]荧蒽、苯并[j]荧蒽、苯并[k]荧蒽、苯并[e]芘、苯并[a]芘及二苯并[a,h]蒽),采用了冷冻研磨、超声浸提法。试验选择了5件样品分别将其粉碎至约2mm3的颗粒,并取一定量的颗粒样品置于研磨仪中进行冷冻研磨至粉末状态。称取加工成粉末状的样品1.00g,加入正己烷-丙酮(1+1)混合溶液10mL,在40℃超声提取35min。将所得提取液氮吹浓缩至近干,用正己烷1mL溶解残渣,所得溶液经滤膜过滤,滤液供气相色谱-质谱分析。采用VB-17MS毛细管色谱柱,在90~300℃温度区间按程序升温模式进行分离。在质谱分析中,用电子轰击离子源和选择离子监测模式。测得8种PAHs的线性范围均在0.05~5.0mg·L-1之间,检出限(3S/N)在0.01~0.02mg·L-1之间。在样品溶液中加入混合标准溶液进行回收试验,测得回收率在84.5%~106%之间,并从测定值计算其相对标准偏差(n=6)在1.6%~4.9%之间。

Freeze-grinding and ultrasonic-extraction were applied to separate 8 polycyclic aromatic hydrocarbons(abbrev.as PAHs),including benzo-[a]-anthracene,chrysene,benzo-[b]-fluoranthene,benzo-[j]-fluoranthene,benzo-[k]fluoranthene,benzo-[e]-pyrene,benzo-[a]-pyrene and dibenzo-[a,h]-anthracene,from samples of styrene butadiene rubber.Five of the rubber samples were selected and cut into small particles sizing 2 mm3.A definite amount of the small sample particles was treated by freeze-grinding in a grinder to give samples in powdered form.1.00 g of the powdered sample was extracted ultrasonically with 10 mL of a mixture of n-hexane and acetone(1+1),at 40℃for 35 min.The extract was collected and evaporated to near dryness by N2-blowing.The residue was taken up with 1 mL of n-hexane,and the solution was filtered through a filtering membrane.The filtrate was used for analysis by GC-MS.GC separation was carried out on the VB-17 MS capillary chromatographic column with programed temperature elevation in the interval between 90-300℃.In MS determination,EI ionization source and SIM monitoring mode were adopted.Linearity ranges for the 8 PAHs were found same between 0.05-5.0 mg·L-1,with detection limits(3 S/N)ranged from 0.01 to 0.02 mg·L-1.Recovery was tested by addition of mixed standard solution of the 8 PAHs to sample solutions as matrixes,giving values of recovery in the range of 84.5%to 106%,and RSDs(n=6)found in the range of 1.6%to 4.9%.