程序升温、程序升流双程序-气相色谱法测定工作场所空气中12种挥发性有机物

Determining 12 individual volatile organic compounds in workplace air by temperature and flow dual programed gas chromatography

  • 摘要:
    目的 建立同时测定工作场所空气中12种挥发性有机物含量的气相色谱检测方法。

    方法 目标物采用活性炭管同时吸附并用二硫化碳解吸。使用DB-FFAP毛细管柱,在程序升温单程序色谱分离的基础上,增加程序升流,双程序分离,提高色谱分离效率,使用氢火焰离子化检测器测定各目标物浓度。

    结果 活性炭管同时采集工作场所空气中甲基环己烷、乙酸乙酯、丁酮、苯、丙烯酸乙酯、甲基异丁(基甲)酮、甲苯、乙苯、(对)二甲苯、(邻)二甲苯、苯乙烯和环己酮12种挥发性有机物,采样效率在95.3%~99.4%之间。样品在4℃冰箱内可稳定保存5 d。精密度范围在0.30%~0.93%之间。在约6~560 μg/mL浓度范围,相关系数均大于0.999,检出限范围在0.012~0.058μg/mL之间,解吸效率在95.8%~103.3%之间,准确度范围在2.1%~4.6%之间。

    结论 该方法准确性好,灵敏度高。从单程序改为双程序分析后,由于色谱分离加快,分析效率提高了57%,适用于工作场所空气中12种挥发性有机物的同时测定。

     

    Abstract:
    Objective To establish a method for simultaneous determination of 12 individual volatile organic compounds in workplace air by gas chromatography.

    Methods The target compounds were adsorbed by activated carbon tube and desorbed by carbon disulfide. On the basis of programmed temperature single-program chromatographic separation, this study additionally adopted programed flow separation method by using DB-FFAP capillary column to improve chromatographic separation efficiency. Then, the individual compounds were measured with flame ionization detector.

    Results The sampling efficiencies of 12 volatile organic compounds including methyl cyclohexane, ethyl acetate, butanone, benzene, ethyl acrylate, methyl isobutyl ketone, toluene, ethylbenzene, para-xylene, ortho-xylene, styrene, and cyclohexanone in the workplace air simultaneously collected by activated carbon tubes were between 95.3% and 99.4%. The samples could be stored in the refrigerator at 4℃ for 5 days. The precisions ranged from 0.30%-0.93%. The correlation coefficients were greater than 0.999 provided the target chemicals were in the range from 7 μg/mL to 500 μg/mL, with the detection limits of 0.012-0.058 μg/mL, desorption efficiencies of 95.8%-103.3%, and accuracies of 2.1%-4.6%.

    Conclusion This method has a high accuracy and sensitivity. After changing from single program analysis to dual-program analysis, the analysis efficiency was increased by 57% due to the accelerated chromatographic separation, indicating that the method is applicable to simultaneous determination of 12 individual volatile organic compounds in the air of workplace.

     

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