流动注射技术结合光谱分析技术测定水体痕量总磷

Measuring Total Trace Phosphorus in Water through Flow Injection Technology Combined with Spectral Analysis Technique

为解决目前水质监测系统存在的量程过大、检出限过高、测定精度低、废液排量高和测定周期长的问题,利用钼酸铵分光光度法结合光谱分析法,在流动注射平台下实现了水体痕量总磷(TP)的测定。测定范围涵盖GB3838-2002和GB18918-2002规定的总磷标准限值。对影响测定结果的因素进行分析并提出解决方案,在优化监测系统工作条件下,总磷测定的量程为0.0~1.2μg/mL,校正决定系数为0.9963,残差平方和为0.0023,最低检出限为0.01μg/mL;重复性测定的相对标准偏差(RSD)为0.49%~3.67%;加标回收率为99.29167%~101.94170%,一次完整测定的废液排量约30.15mL,测定周期约25.50min。

Considering the large range, high detection limit and low measuring accuracy, high effluent displacement and long determination period of the existing water quality monitoring system, the total trace phosphorus in water was measured by making use of ammonium molybdate spectrophotometry and spectroscopic analysis under a flow injection platform. The measurement range covers the specified limits for total phosphorus content of surface waters stipulated in GB 3838-2002 and GB 18918-2002. Analyzing the factors which influencing the measurement result was carried out and solutions to it were proposed to show that, through optimizing the working condition of the monitoring system, the measurement range of total phosphorus stays at 0.0 to 1.2μg/mL along with the correction coefficient of 0.996 3 and the residual squared sum of 0.002 3 and the minimum detection limit of 0.01μg/mL;the RSD of repeatability ranges from 0.49% to 3.67% and the recovery rate from 99.291 67% to 101.941 70%. As for waste liquid displacement of about 30.15mL completely measured, the required period of determination is about 25.50min.