气相色谱法测定环境水体中总石油烃  

Determination of Total Petroleum Hydrocarbons in Environmental Water by GC

作　　者：王述伟[1] 韩文静 李红莉[1] 张凤菊[1] 

机构地区：[1]山东省环境监测中心站,济南250101 [2]山东省环境保护宣传教育中心,济南250012

出　　处：《理化检验（化学分册）》2018年第3期297-302,共6页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

摘　　要：用气相色谱法测定环境水体中挥发性石油烃(VPHC)时,采集水样40mL,调节其酸度至pH<2.0,冷却至4℃后直接上机,用吹扫捕集进样。测定可萃取石油烃(EPHC),则采集水样后取500mL,用二氯甲烷萃取2次,每次用二氯甲烷15mL。合并萃取液,吹氮浓缩至1.0mL以下,用二氯甲烷定容至1.0mL,上机分析。以上两项分析均采用DB-5毛细管色谱柱分离和以火焰离子检测器(FID)测定。在上述两项测定中分别用石油标准溶液和柴油标准品制备标准溶液。测定VPHC时以保留时间在3.439~15.418min之间的C_6H_(14)至C_(10)H_(22)所有色谱峰总面积为纵坐标,以质量浓度为横坐标绘制标准曲线。测定EPHC,则以保留时间在9.027~40.479min之间的C_(10)H_(28)至C_(28)H_(58)所有色谱峰总面积对其相对质量浓度绘制标准曲线。测得的线性范围为:VPHC 0.018~0.25mg·L^(-1)和0.13~2.5mg·L^(-1);EPHC 23.7~474mg·L^(-1),两者的检出限依次为0.003,0.024 mg·L^(-1)。精密度与加标回收试验结果为:相对标准偏差(n=6)均不大于10%,回收率在89.0%~103%之间。For GC-determination of volatile petroleum hydrocarbons （VPHC） in environmental water, 40 mL of the water sample, after adjusting its acidity to pH〈2.0 and cooling to 4℃, was used directly for GC analysis, and the purging and trapping technique for sample introduction was adopted. In the GC-determination of extractable petroleum hydrocarbons （EPHC）, 500 mL of the water sample, was extracted twice with 15 mL of CH2Cl2 in each extraction. The extracts were combined and evaporated to less than 1.0 mL by N2-blowing. CH2Cl2 was added to make its volume to 1.0 mL and it was used for GC-analysis. DB-5 capillary chromatographic column was used for GC-separation of both the VPHC and EPHC, and the FID was used for determination in both cases. The gasoline standard solution and diesel standard sample were used as primary standards in the above 2 analytical items respectively. In preparation of standard curves, values of total peak areas of the chromatographic peaks of compounds of C6H14 to C10H22 appeared in the retention time interval of 3.439 to 15.418 min （for VPHC）, and of the chromatographic peaks of compounds of C10H28 to C28H58 appeared in the retention time interval of 9.027 to 40.479 min （for EPHC） were taken as the ordinate and values of their mass concentrations were taken as the abscissa. The linearity ranges found were between 0.018 to 0.25 mg·L^-1 and 0.13 to 2.5 mg·L^-1 for VPHC and between 23.7 to 474 mg·L^-1 for EPHC, with detection limits of 0.003 mg·L^-1 and 0.024 mg·L^-1 for the 2 items respectively. Tests for precision and recovery by standard addition method were performed, giving results of RSDs （n=6） all ≤ 10%, and recovery in the range of 89.0% to 103%.

关 键 词：吹扫捕集 液液萃取 气相色谱法 总石油烃 环境水体 

分 类 号：O657.7[理学—分析化学]