TD-GC/MS法研究气、液相标准物质对环境空气中苯系物含量测定的差异影响

Difference Effect of Gas or Liquid Phase Standard Reference Material on the Determination of Monoaromatic Hydrocarbons in Ambient Air using TD-GC/MS Method

使用热脱附-气相色谱/质谱法(TD-GC/MS),探究了气、液相标准物质对气体样品中苯系物测定的差异影响。分别绘制了7种苯系物气、液相标准物质的校准曲线,发现液相标物中各苯系物的响应明显高于气相标物。通过一系列猜想的提出及穿透实验、二次解析、甲醇试验等的试验验证,认为甲醇大量电离形成的高能量氛围,提高了苯系物的电离能力,使得液相标物响应增大。因此,气相标准物质比液相标准物质更适合环境空气等气体样品中苯系物的定量检测。最后还通过精密度实验进一步验证了气相标准物质方法的可靠性,并给出了最优样品采集速率为100 mL/min。

TD-GC/MS was used to explore the differential influence of gas or liquid phase standard reference material(SRM) on the determination of monoaromatic hydrocarbons in gas samples.The calibration curves of gas and liquid phase SRMs for 7 kinds of monoaromatic hydrocarbons were drawn,and the response of liquid phase SRM was significantly higher than that of the gas phase SRM.Through a series of conjectures and experimental verifications such as penetration teat,re-desorption teat,methanol test,etc.,it was believed that the high-energy atmosphere formed by the massive ionization of methanol improves the ionization ability of monoaromatic hydrocarbons and increases the response of the liquid phase target.Therefore,gas phase SRM was more suitable for the quantitative detection of monoaromatic hydrocarbons in gas samples such as ambient air than liquid phase SRM.Lastly,the reliability of the gas phase SRM method was further verified by precision experiments,and the optimal sample collection rate 100 mL/min was given.