胶束电动毛细管色谱法测定海底表层沉积物中的苯系化合物

摘要

用胶束电动毛细管色谱法对海底表层沉积物中的苯系化合物进行了分析测定。采用57cm×50μm毛细管柱，以50mmol/L十二烷基硫酸钠-2.0mmol/L四硼酸钠溶液（pH9.16）作为操作缓冲溶液，并加入φ=20%的甲醇作为有机改性剂，电压25kV，检测波长200nm，15min内苯、甲苯、乙苯和二甲苯可获得良好的分离。用峰面积定量，线性范围为2～100mg/L，最小检测浓度分别为0.75mg/L苯，0.45mg/L甲苯，0.39mg/L乙苯，0.1mg/L邻-二甲苯，0.31mg/L对-二甲苯。将该法用来分析石油勘探远景区域海底表层沉积物中的苯系化合物，检测浓度范围为(0.0x～0.x)μg/g。%A method was developed using micellar electrokinetic capillary chromatography (MECC) to analyze and determine the content of the benzene homologue compounds in marine shallow sediment samples. A fused silica capillary of 57cm×50μm (50cm to detector) was used. Running buffer was 2.0 mmol/L aqueous tetraborate solution containing 50mmol/L sodium dodecyl sulfate (pH 9.16) and 20% methanol as an organic modifier. The voltage used was 25 kV. Detection wavelength was 200nm.Benzene, toluene, ethylbenzene and xylene were separated well within 15min.Peak area was measared for quantitative analysis. The calibration curves were linear over 2～100mg/L. The minimum detectable concentrations were 0.75mg/L for benzene, 0.45mg/L for toluene, 0.39mg/L for ethylbenzene, 0.1mg/L for o-xylene and 0.31mg/L for p-xylene. Benzene homologue compounds in marine shallow sediment samples, which deposit in the prospect area of oil exploration, were analyzed using proposed method. The detection ranges obtained for these compounds were (0.0x～0.x)μg/g.