焦化废水中痕量苯并(a)芘的固相萃取和GC-MS检测方法

基于固相萃取(SPE)和气相色谱/质谱联用技术(GC-MS),建立了一种焦化废水中痕量苯并(a)芘(BaP)的定量分析方法。BaP水样添加甲醇改性后经SPE富集净化、二氯甲烷洗脱、氮吹浓缩、二氯甲烷或乙腈定容后采用GC-MS进行定量分析。结果表明:在优化的样品前处理和分析条件下,BaP标准曲线的线性相关系数R2>0.99,方法回收率为79.6%~85.5%,方法检出限和定量限分别为4.33 ng/L和14.45 ng/L。该方法应用于内蒙古某焦化厂二级生化出水加标样品中BaP的测定,得到BaP的回收率为83.3%~89.3%,表明其灵敏度高、选择性好,适用于焦化废水中痕量BaP的定量检测。

A DETECTION METHOD FOR TRACE BENZO (a) PYRENE IN COKING WASTEWATER BY SOLID-PHASE EXTRACTION AND GC-MS ANALYSIS

Based on solid phase extraction (SPE) and gas chromatography/mass spectrometry (GC-MS),the study herein established a quantitative analysis method for trace benzo (a) pyrene (BaP) in coking wastewater.The BaP-containing water samples were enriched and purified by SPE after being modified by methanol,then eluted by dichloromethane,concentrated by nitrogen blowing,and quantified by GC-MS after constant volume of dichloromethane or acetonitrile.The results showed that,after the optimization of sample pretreatment and under the analysis conditions,the linear correlation coefficient (R2) of BaP standard curve was greater than 0.99,the recovery rate was in the range of 79.6%~85.5%,the detection limit and quantitative limit were 4.33 ng/L and 14.45 ng/L,respectively.This method was then applied to the determination of BaP in the secondary effluent of a coking plant in Inner Mongolia.The recoveries of spiked BaP samples were in the range of 83.3%~89.3%,indicating that this method presented high sensitivity and good selectivity.It is suitable for the quantitative determination of trace BaP in coking wastewater.