Research For Rapid Determination Of Trichloroethylene, Vinyl Chloride, Methyl Mercaptan In The Atmospheres

In response to the emergencies of chemical poisoning incidents caused by the volatile organic compounds, a quick and accurate detection method was needed to determine the types of poison and harmful levels. In order to deal with the accident and treat the patients timely and effectively, we have developed a field detection method of qualitative and quantitative determination of three kinds of volatile organic compounds. Present detection methods of the three harmful factors were detection tubes, electrochemical sensors, portable gas chromatography, and laboratory tests, which would be restrictions on the field determination of chemical poisoning. A portable gas chromatography mass spectrometry (GC-MS) was used to develop the methods. The survey mode was applied for rapid qualitative test by the rapid mass scanning. The accurate quantification of the target compounds was via the standard curve.Objective The portable gas chromatography-mass spectrometry(GC/MS) methods were developed for field determination of TCE. vinyl chloride, and methyl mercaptan.Methods Static gas distribution act and field experimental methods were used to optimize the determination parameters of the portable GC-MS. The target compounds were qualitatively detected by the NIST library search. According to the ratio of the concentration is in direct proportion to the ratio of the peak area of the analytes and internal standard (Bromopentafluorobenzene). the calibration curve was established by the calibration function of the portable GC-MS. And the precision, accuracy. LOQ and so on were assessed. Results Experimental results show that TCE in the range of 14.5-145.7 mg/m3 with good linear response. The correlation coefficient (r2) averaged 0.997.The LOD and LOQ of the method were 0.091 mg/m3 and 0.305mg/m3.The recovery ranged 94.17%-103.13%. Compared with the lab method, the result was no significantly different (p>0.05). Vinyl chloride concentration has good linear response in the range of 5.12-40.99 mg/m3. The correlation coefficient (r2) averaged 0.996. The LOD and LOQ were 0.1844mg/m3 and 0.6146mg/m3. The recovery ranged 75.46%-97.83%. Compared with the lab method, the result was no significantly different (p>0.05). Methyl mercaptan concentration has good linear response in the range of 0.16-33.00 mg/m3.The correlation coefficient (r2) averaged 0.994. The LOD and LOQ were 0.20mg/m3 and 0.66mg/m3.The recovery ranged 84.90%-107.10%.Conclusion The method has high sensitivity and accuracy for the rapid qualitative and quantitative determination of trichloroethylene, vinyl chloride, and methyl mercaptan in the chemical poisoning field.