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目的探索建立热解吸-气相色谱法测定工作场所空气中芳香烃类化合物后的留样复测方法。方法从工作场所采集的空气样品经热解吸-气相色谱法检测后,剩余的解吸气体按照第1次采样时的方向,在10 ml/min的低流量条件下重新模拟采样吸附到原来的吸附炭管中,然后采用与第1次测定时同样的实验方法和条件进行第2次解吸测定。结果在选定的实验条件下,各芳香烃化合物第2次的解吸效率接近第1次的解吸效率;当留样比例超过50%时,第2次测定的结果与第1次测定的结果差异无统计学意义,在一定的时间内二次解吸效率测定结果的相对标准偏差(RSD)均<7%(n=6)。结论本法简单、快捷,不增加任何耗材,适用于工作场所空气中多种芳香烃类化合物测定后的留样复测。
Objective To establish a method for the determination of residual samples after the determination of aromatic hydrocarbons in the air by thermal desorption-gas chromatography. Methods After the air samples collected from the workplace were detected by thermal desorption-gas chromatography, the remaining desorbed gas was resampled to the original adsorbent at the low flow rate of 10 ml / min according to the direction of the first sampling Carbon tube, and then using the same test method and conditions of the first measurement for the second desorption measurement. Results Under the selected experimental conditions, the second desorption efficiency of each aromatic hydrocarbon compound was close to the first desorption efficiency. When the sample retention ratio exceeded 50%, the result of the second measurement was different from the result of the first measurement There was no statistical significance. The relative standard deviations (RSDs) of secondary desorption efficiency were all less than 7% (n = 6) in a certain period of time. Conclusion This method is simple, fast and does not add any consumables. It is suitable for the re-measurement of samples after the determination of aromatics in the air in the workplace.