工业污水中挥发性有机物的顶空固相微萃取-气相色谱测定法

Determination of volatile organic compounds in industrial wastewater by headspace solid phase microextraction coupled with gas chromatography

目的建立顶空固相微萃取-气相色谱法（SPME-GC）同时测定工业污水中苯系物、氯苯类挥发性有机物的方法。方法移取10 ml水样于15 ml样品瓶中,加入2.0 g Na Cl,在40℃平衡30 min,用聚二甲基硅氧烷（PDMS,100μm）的萃取头顶空萃取30 min后,于250℃解吸3 min。用配有HP-FFAP毛细管柱（30 m×0.32 mm,0.25μm）的7890A气相色谱仪进行分离测定。结果在4.24~8 800μg/L的线性范围内,所得12种苯系物和氯苯类挥发性有机物的回归方程均呈较好的线性关系（r〉0.995）。该方法的检出限为0.39~5.0μg/L,回收率在71.8%~89.6%之间,日内RSD在2.0%~5.8%之间,日间RSD在2.3%~5.9%之间。结论该方法快速、简单、检出限低、准确度高、精密度好,适合于污水中12种挥发性有机物的痕量分析检测。

Objective To establish a method for the determination of the homologous series of benzene and chlorobenzenes volatile organic compounds in industrial wastewater by headspace solid-phase microextraction coupled with gas chromatography. Methods The experiment conditions for HS-SPME-GC were confirmed as follows： 10 ml water and 2.0 g sodium chloride（Na Cl） were added in 15 ml headspace bottle and the equilibrium time was 30 min at 40 ℃, the extraction was conducted with 100 μm PDMS fiber about 30 min; The desorbing time for the SPME was 5 min at 250 ℃. The target compounds were detected by 7890 A gas chromatography equipped with HP-FFAP capillary column（30 m×0.32 mm,0.25 μm）.Results The correlation coefficients were higher than 0.995 in the range of 4.24-8 800 μg/L for the 12 kinds of volatile organic compounds,and the limits of detection were 0.39-5.0 μg/L,the average recoveries were in the range of 71.8%-89.6%.Intra-day precisions were 2.0%-5.8%, and the inter-day precisions were achieved with 2.3%-5.9%. Conclusion The method is rapid,simple,showes low detection limit,high accuracy, good precision and is applicable to the determination of 12 kinds of trace volatile organic compounds in industrial wastewater.