气相色谱-质谱法研究敌百虫在气相色谱分析过程中产生的分解产物

Study on Decomposed Products of Trichlorfon in Process of Gas Chromatographic Analysis by Mass Spectrometry

利用气相色谱-质谱联用技术对敌百虫在气相色谱分析过程中产生的分解产物进行定性研究。通过质谱解析鉴定出敌百虫的分解产物有三氯乙醛、磷酸二甲酯和敌敌畏。研究了气相色谱条件如进样口温度、柱温升温速率、进样方式对敌百虫分解产物的影响。实验结果表明:这3种因素对敌百虫的稳定性均有不同程度的影响,其中进样口温度是导致敌百虫分解的主要因素,进样口温度越高,敌百虫的分解量就越大。

The decomposed products of trichlorfon in gas chromatographic analysis were identified by mass spectrometry （MS）. After MS interpretation, three decomposed products, trichloroacetaldehyde, dimethyl phosphite and dichlorvos were identified. The effects of gas chromatographic conditions on decomposed products of trichlorfon, e.g. injection temperature, injection mode and oven ramp, were studied. The experiments showed that all of the factors have effects on decomposed products of trichlorfon, however, the injection temperature is the key factor to cause trichlorfon being decomposed. The higher the injection temperature is, the bigger the amount of trichlorfon being decomposed. When the injection temperature was raised from 150 ℃ to 250 ℃, the remaining trichlorfon fell from 86% to 20%. Therefore, on-cold column injection mode gas chromatography or high performance liquid chromatography was recommended for exact quantification of trace trichlorfon.