摘要
在一定的酸度条件下，乙基紫与磷钼杂多酸所形成的离子缔合物于５５５ｎｍ处有一最大吸收，在此波长处试剂空白的吸收最小．基于这一事实，本文提出了直接测定痕量磷的流动注射分光光度法．方法灵敏度高，选择性好，水中常见离子不干扰痕量磷的测定，工作曲线的线性范围为０－４００μｇ／ｌ的磷，检测下限达０．７μｇ／ｌ，以１２０ｈ－１采样频率，对各种天然水样进行测定，回收率为９８．２％－１０２．５％，变异系数为０．１％－４．５％．
With the presence of a non-ionic surfactant,and an appropriateacidic medium,the maximum wavelength of the ion-associate of molybdophosphate formed with Ethyl violet are 555nm at the range of 500-700nm,where the absorbance of the reagent blank of Ethyl violet is quite low.Based on the fact,a flow injection spectrophotometric method for direct determination of trace amounts of phosphorus in water with high sensitivity and selectivity is developed. The calibration graph is linear within 0-400μg/l of P,the detection limit is 0.7μg/l for P,and the coefficient of variation for the determination of 5ng/ml of P is 4.0%.The common ions in water do not interrupt the determination. This method has been applied to the determination of soluble orthophosphate in natural water and tap water samples. The recoveries are 98.2%-102.5%,and the coefficients of variation for the samples are 0.1%-4.5%.The sampling rate is up to 120h -1 .
基金
国家自然科学基金
关键词
流动注射分析
分光光度法
水
正磷酸盐
磷
flow injection analysis
spectrophotometry
molybdophosphateand ethyl violet
phosphorus
