称取记号笔笔芯中油墨0.200 0 g，加入乙酸乙酯至体积为5.0 mL，涡旋提取2 min，将提取液流经HLB固相萃取柱进行净化处理。经净化的流出液用乙酸乙酯定容至10.0 mL，经0.22 μm滤膜过滤，取滤液按仪器工作条件进行气相色谱-质谱法分析。选择HP-INNOWax毛细管色谱柱，在35~220℃之间按程序升温模式对8种挥发性苯系物（苯、甲苯、乙苯、对二甲苯、间二甲苯、异丙苯、邻二甲苯和苯乙烯）进行分离，并在电子轰击离子源（EI）和选择离子监测（SIM）模式下进行质谱测定。8种挥发性苯系物均在0.1~5.0 mg·L^-1内与其相应的峰面积呈线性关系，其检出限（3S/N）为0.06~0.18 mg·kg^-1。在阴性样品的基础上，在3个浓度水平上进行加标回收试验，测得8种化合物的回收率为79.8%~114%，测定值的相对标准偏差（n=5）为0.20~11%。应用此方法分析了116支记号笔中不同颜色的油墨样品，苯系物的检出率为76.9%，其质量分数为0.33~3.49×10⁴mg·kg^-1。

0.200 0 g of ink in the core of a marking pen was taken and extracted with 5.0 mL of ethylacetate for 2 min. The extract was purified by passing through HLB solid phase extraction column. Eluate together with the washings was collected, and its volume was made up to 10.0 mL with ethylacetate. After filtering through 0.22 μm filtering membrane, the filtrate was used as testing solution for determination of 8 volatile benzene homologues (i.e., benzene, toluene, ethylbenzene, p-xylene, m-xylene, iso-propyl-benzene, o-xylene and styrene) by GC-MS under the working condition of the instrument. HP-INNOWax capillary chromatographic column with programmed temperature elevation in the range from 35℃ to 220℃ was adopted for the separation of the 8 benzene homologues, and then determined by MS under the mode of EI and SIM. Linearity ranges of the standard curves of the 8 benzene homologues were found same in the range of 0.1-5.0 mg·L^-1. Detection limits (3S/N) found were in the range of 0.06-0.18 mg·kg^-1. On the base of blank samples, mixed standard solutions at 3 concentration levels were added and recovery test were performed. Recoveries of the 8 compounds were found in the range of 79.8%-114%. Values of RSDs (n=5) found were ranged from 0.20% to 11%. 116 marking pens with ink of various colors were analyzed by the present method, rate of detection of the 8 benzene homologs attained to a value of 76.9%, with their mass fractions in the range of 0.33-3.49×10⁴mg·kg^-1.