不同氯代毒杀芬的全二维气相色谱分离分析方法研究

Group Separation of Toxaphene by Comprehensive Two-Dimensional Gas Chromatography

建立了全二维气相色谱-电子捕获检测器法（GC×GC-μECD）分离分析不同氯代毒杀芬的新方法.通过实验优化,以非极性的DB-1MS为第1根色谱柱,以中等极性的BPX-50为第2根色谱柱对工业毒杀芬不同氯代化合物进行分离分析,获得良好的分离效果.采用基质曲线外标法进行定量分析,线性系数（r2）均大于0.99,不同氯代毒杀芬的检出限（S/N=3）为0.2～0.6 μg/L,相对标准偏差（RSD,n=7）为9％～20％,利用土壤为基质进行加标实验,不同氯代毒杀芬同类物的回收率为65％～105％.

A new method was developed for the group analysis of toxaphene mixtures using a compre- hensive two- dimensional gas chromatography coupled with micro electron -capture detector （GC × GC - μECD）. Different polarity and selectivity columns, including DB - XLB, DB - 1 MS and BP - 1, were used as first dimension and combined with columns of increasing polarity in the second di- mension, i.e. BPX - 50. An DB - 1 MS （20 m × 0. 25 mm× 0.25 μm） combination with BPX - 50 （2 m ×0. 1 mm × 0. 1 μm） yielded highly structured chromatograms and revealed a complex mixture of 923 compounds. GC × GC - μECD parameters, including temperature programs, carrier gas flow rate and modulation period were also optimized. Toxaphene congeners were well separated with the optimized methods. The peak areas of all congeners of different chlorinated toxaphene were calculat- ed. It is found that hepta-, octa- and nona-chlorinated compounds were the major components and contribute 85% of the total toxaphene mass. The matrix - matched external standard calibration curves were used for quantitative analysis. Linear range of this method were 10 -500 μg/L and limit of detection were 0. 2 - 0.6 μg/L of the different chlorinated toxaphene. The repeatability and repro- ducibility at a concentration of 10 μg/L evaluated with RSDs（ n = 7） of 9% -20% . It can be seen the use of comprehensive two - dimensional GC substantially improves the quality of toxaphene analy- sis compared to one - dimensional gas chromatography （ 1D - GC ） , hundreds congeners could be separated in toxaphene after a run which took less than 2 h. The results illustrate the potential of the GC × GC - μECD developed for the fast analysis of trace amount of complex compounds.