全自动流动注射法测定餐(饮)具表面残留阴离子合成洗涤剂

Determination of anion synthetic detergent residue on the surface of dinner and drinking set by automatic flow injection analysis

目的研究建立用全自动流动注射法测定餐(饮)具表面残留阴离子合成洗涤剂的检测方法。方法将表面光滑清洁的餐(饮)具用100 ml蒸馏水分3次~5次冲洗整个内表面,收集冲洗液制备成样液,通过亚甲蓝与阴离子表面活性剂作用,生成蓝色的盐类,用三氯甲烷萃取,在652 nm波长下,通过全自动流动注射仪进行在线比色分析。结果方法线性关系良好,相关系数为0.9996;最低检出限为3.6μg/L;高、中、低3种浓度制成的加标样品回收率为92.6%~97.5%;相对标准偏差(RSD)为1.6%~5.2%(n=7)。另外,采用本法对2份标准物质样品进行处理和检测,检测结果均在标准值不确定度控制范围内。结论本方法具有高效、灵敏、准确、精密度好、检出限低、自动化程度高等特点,适用于餐(饮)具表面残留阴离子合成洗涤剂的测定。

Objective To establish a method for the determination of anionic synthetic detergents on the surface of meals(drinking)with automatic flow injection.Methods The smooth and clean surface of the dishes was washed with 100 ml of distilled water 3 times to 5 times to the entire inner surface,and the washing liquid was collected to prepare a sample liquid,which was reacted with methylene blue and an anionic surfactant to form a blue salt.The class was extracted by chloroform and subjected to on-line colorimetric analysis by a fully automated flow injector at 652 nm.Results The linear relationship was good,the correlation coefficient was 0.9996;the minimum detection limit was 3.6μg/L;the recoveries of spiked samples prepared at high,medium and low concentrations were within 92.6%-97.5%;relative standard deviation(RSD)was within1.6%-5.2%(n=7).In addition,two standard substance samples were processed and tested by this method,and the test results were all within the control range of the standard value uncertainty.Conclusion This method is characterized by high efficiency,sensitivity,accuracy,precision,low detection limit and high degree of automation.It is suitable for the determination of residual anionic synthetic detergent on the surface of meals.