跨界水体联合监测中总磷测定的问题探讨

研究了不同分析方法、去浊度手段和预处理方式对地表水总磷测定的影响。结果表明:钼酸铵分光光度法在跨界水体联合监测中较连续流动分析法、氯化亚锡还原光度法、孔雀绿-磷钼杂多酸分光光度法更为适用;在水样没有色度的情况下,采用浊度-色度补偿法和离心法都能有效消除浊度干扰,相对误差±10%;预处理方式的不同是导致各监测单位测定结果可比性差的最关键因素。

Discussions on Determination of Total Phosphorus in Associated Cross border Water Quality Monitoring

The effects of different analysis methods for removing turbidity and sample pretreatments on the determination of total phosphorus in surface water were studied. The results showed that ammonium molybdate spectrophotometry was more suitable than continuous flow analysis method, stannous chloride reductive spectrophotometry and PMA-Malachite green spectrophotometry in asso-ciated cross-border water quality monitoring. When the chromaticity of water samples did not exist, turbidity-chromaticity compen-sation and centrifugation could effectively remove the turbidity interference with relative error of less than ± 10%. Differences of pretreatment methods directly influenced the testing result of total phosphorus, which was the most important factor resulting in poor comparability of determination results between monitoring institutions.