以单壁碳纳米管为涂层的固相微萃取纤维在水中苯氧基羧酸类除草剂测定中的应用

Determination of Phenoxy-acid Herbicides in Water with Solid Phase Microextraction Fiber Coated with Single-walled Carbon Nanotubes

采用以单壁碳纳米管（SWCNTs）为涂层的固相微萃取（SPME）纤维,通过衍生化-SPME-GC-ECD方法,研究了不同实验条件对SWCNTs纤维萃取效率的影响,考察了SWCNTs纤维的使用寿命及涂层的化学稳定性,建立了水中5种苯氧基羧酸类除草剂的测定方法.结果表明,SWCNTs纤维可耐受的pH=1,使用寿命可达160次,说明SWCNTs纤维具有良好的化学稳定性.方法的线性范围为0.5～ 50.0μg/L（麦草畏、2,4,5-三氯苯氧丙酸和2,4,5-三氯苯氧乙酸）,1.0 ～100.0μg/L（2,4-二氯苯氧乙酸）和5.0～500.0 μg/L（2,4-二氯苯氧丁酸）;LOD为0.03 ～0.25 μg/L,LOQ为0.08～0.84 μg/L.

By using solid phase microextraction （SPME） fiber coated with single-walled carbon nanotubes, an analytical method based on derivatization-SPME-GC-ECD method was established for the determination of 5 phenoxy-acid herbicides in water. The extraction parameters of the method were optimized, and the chemical stability of the SWCNTs fiber was investigated. The results showed that due to the inert nature of graphite, the SWCNTs fiber could be used at pH as low as 1 and the extraction efficiency of the fiber would not decline significantly after 160 extractions, showing excellent chemical stability. The linear range of the established method was 0.5-50.0 μg/L for Dicamba, （＋） -2-（2 ,d ,5-trichlorophenoxy） propionic acid （2,4,5-TP） and trichlorophenoxy acetic acie （ 2,4,5-T）, 1.0-100.0 μg/L for 2,4-dichloraphenoxy acetic acid （2,4-D）, and 5.0-500.0 μg/L for 4-（2,4-dichlorophenoxy）bytyric acid （2,4-DB）. The LODs and LOQs were 0.03- 0.25 μg/L and 0.08-0.84 μg/L, respectively.