Determination Of VOCs In The Air Of Shoemaking Workshop With Gas Chromatography

Shoemaking workshops use a lot of raw materials and have a lot of VOCs pollution.The aim of this dissertation is to apply GC to the analysis of the VOCs in the air of shoemaking workshop,do research on the different pretreatment techniques and detectors.The major contents are described as follows:1.Determination of methanal in the air of shoemaking workshop with derivation-gas chromatography.A method of analyzing methanal is developed.Formaldehyde in air is collected by pure water.After adding 2,4-dinitrophenylhydrazine,it is extracted and analyzed.The results show that the optimal conditions are pH=6 and 60℃ for 30 minutes in a water bath.The linear correlation coefficient of the standard curve,the detection limit,the lowest detection concentration and the recovery of Formaldehyde in the sample are investigated.The experimental results show that the method has good selectivity,accurate and reliable results,and can replace the spectrophotometer widely used.2.Determination of DMF and DMA in the air of shoemaking workshop with two-stage thermal desorption-gas chromatography.A method of analyzing DMF and DMA in the air of shoemaking workshop is developed by applying two-stage thermal desorption-gas chromatography.The effects of column type,detector type and thermal desorption temperature on the experimental results are investigated.Finally,FFAP as chromatographic column,NPD as detector and 280℃ as thermal desorption temperature is used.The linear correlation coefficient of standard curve,the desorption efficiency,the minimum detectable quality and the detectable concentration are calculated.Compared with the national standard method,the sensitivity can be improved effectively by using this method.The pollution sources are also studied.3.Determination of 17 VOCs in the air of shoemaking workshop with two-stage thermal desorption-gas chromatography.A method of analyzing 17VOCs simultaneously in the air of shoemaking workshop is developed.The effects of thermal desorption temperature and column temperature on the detection are investigated.Compared with the national standard method,the detection limit of this method is significantly lower and many trace substances are detected.The method is suitable for the determination of the above 17 substances in the air of shoemaking workshop.