Monitoring And Analysis Of Volatile Organic Compounds In Domestic Drinking Water

With the rapid economic development and industrial progress,volatile organic compounds(VOCs)have been an important group of environmental pollutants,which may constitute a serious threat to human health.VOCs have toxic effects on nervous system,immune system and some other organs,resulted in health risks such as sensory,irritation,asthma,respiratory effects and carcinogenic effects.Since VOCs are permeable,liposoluble and volatile,they are easily penetrate into the water aquifers and pollute water sources.Therefore,they have been a part of water pollution that cannot be neglected.In China,the standards of drinking water still exists great disparities with western countries in both the amount of indices and the maximum residue limit of some highly toxic VOCs.In this paper,based on the test method published by American EPA and China National Standard,coupled with purge and trap as well as gas chromatography-mass spectrometry technique,by optimizing the detection methods of 56 kinds of VOCs in drinking water,we got good results,and applied this method to the detection of drinking water in Quzhou.(1)Fifty-five volatile organic compounds and trace epichlorohydrin in drinking water were detected by gas chromatography-mass spectrometry with purge and trapping method.After the optimization of purge and trap conditions,using DB-624(30 m*0.25 mm*1.4μm)column,split injection mode(split ratio was 1:30)and selective ion mode(SIM)detection,55 kinds of volatile organic compounds in the drinking water had good separation effect,the linear range of VOCs was 0.5μg/L to 40μg/L(r=0.9920～0.9999).The detection limit was 0.004 μg/L to 0.04 μg/L.The relative standard deviation was 5.1%to 12%(n=9).The recoveries of spiked samples at the level of 1μg/L and 15μg/L were in the range of 86.7%～110.8%.The method shortend the analytical cycle greatly,and was accurate,highly sensitive,with good exactitude and wide linear range,met methodological requirements.On the basis of the study of 55 kinds of VOCs detection method in the water,by changing the split ratio(1:10)and column temperature program,the detection limit could reach 0.02μg/L,and met the national standard limit value requirements,and was suitable for the determination of trace epichlorohydrin in drinking water.(2)Monitoring of VOCs in domestic drinking water in Quzhou cityIn this chapter,the above detection methods were applied into the monitoring of VOCs in domestic drinking water.According to the distribution and usage situation of domestic drinking water in Quzhou city,Seasonal detection was carried out with samples covering urban tap water,drinking water in towns,drinking water m schools,as well as bottled water sold in markets.A total of 682 test samples were analyzed,the results showed that only 2 samples from the chloroform content exceed the standard,but p-isopropyltoluene was detected in 50 water samples,higher content of some samples(in the range of<0.006-126 g/L).It showed that the pollution of volatile organic compounds in drinking water overall is good in Quzhou city,but the problem with the introduction of halogenated hydrocarbons in drinking water disinfection process should pay attention,and the abnormal p-isopropyltoluene also needed the relevant departments to investigate and confirmed the existence of pollution.