饮用水中在烧煮过程中余氯及卤代烃含量变化研究

Study on the Changes of Residual Chlorine and Halogenated Hydrocarbon Content in Drinking Water During Cooking

运用分光光度法、吹扫捕集气质联用法测定了饮用水在烧煮过程中余氯及12种含氯卤代烃的含量。结果表明:自来水在煮沸后的240 s内,余氯与煮沸时间呈负相关,余氯降低了97%;直饮水、矿泉水中余氯未检出。在煮沸的前60s内,水样中大部分含氯卤代烃与煮沸时间呈负相关,其中:自来水中三氯甲烷、四氯化碳、一溴二氯甲烷、三氯乙烯、1,2-二氯乙烷、四氯乙烯、二溴一氯甲烷分别由10.146 1、0.135 5、0.925 2、2.564 7、0.217 4、0.547 0、0.877 8μg·L^(-1)降至0.0、0.0、0.0、2.458 7、0.177 0、0.423 6、0.870 7μg·L^(-1);直饮水中三氯甲烷、三氯乙烯分别由2.073 2、2.365 9μg·L^(-1)降至0.0、2.343 1μg·L^(-1);矿泉水中1,2-二氯乙烷、三氯乙烯分别由0.149 2、2.391 7μg·L^(-1)降至0.0、2.227 4μg·L^(-1)。因此,自来水、直饮水、矿泉水宜在煮沸60 s后饮用,更利于人体健康。

Spectrophotometry,purge and trap gas mass spectrometry were to determine the residual chlorine and 12 kinds of chlorinated halogenated hydrocarbons in drinking water during the cooking process. The results showed that within 240 s after the tap water was boiled,the residual chlorine was negatively correlated with the boiling time, and the residual chlorine was reduced by 97%;residual chlorine was not detected in direct drinking water and mineral water. And in the first 60 s of boiling,most of the chlorinated halogenated hydrocarbons in the water sample were negatively correlated with the boiling time.Among them:chloroform,carbon tetrachloride, bromodichloromethane, trichloroethylene,1,2-dichloroethane,tetrachloroethylene,and dibromomonochloromethane decreased from 10.146 1, 0.135 5, 0.925 2, 2.564 7, 0.217 4, 0.547 0, 0.877 8 μg·L^(-1) to 0, 0, 0, 2.458 7, 0.177, 0.423 6, 0.870 7 μg·L^(-1);chloroform and trichloroethylene in direct drinking water decreased from 2.073 2, 2.365 9 μg·L^(-1) to 0, 2.343 1 μg·L^(-1),respectively;1,2-dichloroethane and trichloroethylene in mineral water decreased from 0.149 2, 2.391 7 μg·L^(-1) to 0, 2.227 4 μg·L^(-1),respectively.So tap water,direct drinking water,and mineral water should be boiled for 60 s before drinking,which is more beneficial to human health.