亚甲蓝法测定生活饮用水中阴离子合成洗涤剂及干扰因素分析  

The anionic synthetic detergent in drinking water detected by submethylene blue method and its influencing factors

作　　者：吴艳玲 王占辉[1] 刁丹红 封燚 杨慧卉[1] 李依霖 WU Yanling;WANG Zhanhui;DIAO Danhong(Chengde Center for Disease Control and Prevention,Hebei,Chengde 067000,China)

机构地区：[1]河北省承德市疾病预防控制中心,067000 [2]河北省承德市市场监督管理局

出　　处：《河北医药》2020年第24期3786-3788,3792,共4页Hebei Medical Journal

基　　金：承德市科学技术研究与发展计划项目(编号:202002A003)。

摘　　要：目的建立一种生活饮用水中阴离子合成洗涤剂的快速检测方法,实现其快速准确测定。方法取20 ml待测水样于25 ml比色管中,加入4 ml亚甲蓝溶液,混匀后加入4 ml三氯甲烷。连续振摇120次(45 s),分液漏斗中静置分层,分出有机相于650 nm波长,以三氯甲烷为参比测量吸光度。结果本方法测定生活饮用水中阴离子合成洗涤剂在0.05~1.00 mg/L范围内线性关系良好,相关系数r=0.9998,检测限0.01 mg/L。样品低、中、高3个浓度水平的加标实验,回收率为97.4%~106.3%,精密度为0.68%~2.34%(n=6)。对水样pH值缓冲范围为2.5~11.5,水样中游离氯含量超过0.25 mg/L时对本方法具有明显的负干扰。结论本方法操作简单快速,测定准确,抗干扰能力强。水中游离氯的含量对本方法及国标亚甲蓝方法均具有负干扰,在实际水样检测过程中应予以关注。Objective To establish a rapid detectinon method to detect the anionic synthetic detergent in drinking water,in order to detect it fsatly and accurately.Methods The 20 ml of the water sample to be tested was placed in a 25 ml stoppered colorimetric tube,and 4ml of methylene blue solution and 4ml of chloroform were added after mixing.The mixture was shaken continuously for 120 times(45s),and standing layering in tap funnel.The chloroform phase was separated at a wavelength of 650 nm,and the absorbance was measured with chloroform as a reference.Results The anionic synthetic detergent in drinking water detected by the method had a good linearity in the range of 0.05 to 1.00mg/L,the correlation coefficient(r)was 0.9998,and the lowest detection concentration was 0.01mg/L.The samples were spiked at low,medium and high levels.The coefficient of recovery ranged from 97.4%to 106.3%,and the precision ranged from 0.68%to 2.34%(n=6).The method had a pH buffer range of 2.5 to 11.5 for water samples.When the free chlorine content in the water sample exceeded 0.25mg/L,which had obvious negative interference with the method.Conclusion The method is simple,fast,accurate,which has strong anti-interference ability.The free chlorine content in water has a certain degree of negative interference with the method and with the national standard methylene blue method,which should be paid much attention to during actual water sample detection.

关 键 词：阴离子合成洗涤剂 饮用水 干扰因素 游离氯 

分 类 号：R123.1[医药卫生—环境卫生学]