流动注射-分光光度法测定河口水中磷酸盐及盐效应的校正办法

FI-Spetrophotometric Determination of Phosphate in Estuarine Water and Method of Correction for Salt Effect

摘要: 提出了用流动注射分光光度法测定河口水中磷酸盐,并对可能干扰测定的折射效应、基体效应和动力学效应等3种类型盐效应进行了讨论。结果表明:磷酸盐的测定仅受折射效应的干扰,试验通过调整样品进样量、反应时间和积分时间等参数对其进行校正。方法线性范围为5.00~480 μg·L-1,检出限(3S/N)为1.04 μg·L-1。方法用于分析河口水样,测定值的相对标准偏差(n=7)为1.4%,平均回收率为100.4%。

Abstract: A method of FI-spectrophotometry for the determination of phosphate in estuarine water was proposed. Salt effects, including refraction effect, matrix effect and kinetic effect, were discussed, and it was found that only refraction effect interfered with the determination. It was shown that this interference was avoided by adjusting the sample volume, reaction time, and time of integration. Linearity range was kept between 5.00-480 μg·L-1 of phosphate, with detection limit (3S/N) of 1.04 μg·L-1. The proposed method was applied to the analysis of estuarine water sample, giving value of RSD (n=7) of 1.4%, and value of average recovery of 100.4%.