优化GC检测2,4,6-三氯苯甲醚的萃取条件

Optimization of extraction conditions of 2,4,6-trichloroanisole determination by gas chromatography

2,4,6-三氯苯甲醚（TCA）的萃取条件直接影响气相色谱技术分析检测结果的准确性。最佳萃取条件为：萃取头涂层聚二甲基硅氧烷-二乙烯基苯（PDMS/DVB）,萃取液体积10m L,平衡时间20min,萃取时间35min,氯化钠含量为30%,萃取温度30℃,搅拌转速40r/s。联合气相色谱电子捕获技术（GC-ECD）和气相色谱质谱联用技术（GC-MS）验证该结果,显示：线性相关系数R2分别为0.9974和0.9998;相对标准偏差RSD分别为1.26%～3.85%和0.89%～3.00%;回收率：60%～72.50%和86%～101%;最低检出限LOD：0.30×10^-12g/L和1.00×10^-11g/L;定量限LOQ：1.10×10^-12g/L和0.20×10^-9g/L。两种仪器均满足检测要求,GC-ECD灵敏度更高,GC-MS定量更精准。

The accuracy of determination results of 2,4,6-trichloroanisole（TCA） was influenced directly by the extraction conditions of TCA when gas chromatographic technique was used. Extraction conditions of headspace solid phase microextraction TCA were optimized by the single factor experiment and orthogonal experiment in this research. The optimum conditions were obtained as follows= polydimethylsitoxane- divinylbenzene （PDMS/DVB） as the extraction fiber,volume of extraction liquid 10mL, equilibrium time 20min, extraction time 35rain,sodium chloride concentration 30% ,extraction temperature 30 ℃ and magnetic stirring 40r/s. To verify the obtained optimum conditions,TCA was detected with gas chromatography with electroncapture detection（GC-ECD） and gas chromatography with mass spectrometric detection（GC-MS）. The result showed that correlation coefficient（FF） were 0.9974 and 0.9998 respectively. The precision（RSD） were 1.26%N3.85% and 0.89%--3.0% Recovery ranged from 60% to 72.5% and 86% to 101%. The limit of detection（LOD） were 0.30×10^-12g/L and 1.00×10^-11g/L. The limit of quantification（LOQ） were 1,10×10^-12g/L and 0.20×10^-9g/L. Both of methods could satisfy the requirements of analysis. The sensitivity of the GC-ECD was higher,nonetheless,the quantification of GC-MS was more accurate.