地表水高锰酸盐指数自动监测仪差异性研究

针对地表水高锰酸盐指数自动监测仪质量控制合格率偏低及样品和试剂消耗量大的问题,分别选择3种国产及3种进口的不同型号监测仪,通过工艺比较、性能测试、低浓度及较高浓度实际水体环境下的质量控制测试及长时间连续在线监测4个方面进行差异性研究。结果表明:不同仪器采用不同工艺,影响标准物质核查结果及运行维护成本和便捷性;不同仪器性能测试结果基本符合要求;不同仪器质量控制合格率差异显著,标准物质核查合格率(低浓度的为32%~57%,高浓度的为44%~80%)低于实际水体比对(低浓度实际水体为66%~79%,较高浓度实际水体为71%~100%),国产仪器质量控制合格率与进口仪器整体相当;不同仪器连续在线监测数据有效率及相对偏差±20%内的数据量占比差异显著,而国产仪器与进口仪器在这2个方面整体差异较小。

Study on the Difference Analysis of Permanganate index Automatic Analyzers in Surface Water Bodies

Three pieces of domestic and imported permanganate index automatic analyzers were respectively selected to study the problem of low test-pass-rate of quality control (QC) tests and excessive consumption of reagents. It was based on four tests to study difference, including technology comparison, performance tests, QC tests in low-concentration water body and high-concentration water body, and continuous online monitoring in a long time. It was found that different technology was adopted by different analyzers, which could affect test-pass-rate of certified reference materials and the cost and convenience of operation and maintenance. The results of performance tests were basically complied with the requirements. There was significant difference between test-pass-rate of QC tests. The test-pass-rate of certified reference materials (low concentration was from 32% to 57% and high concentration was from 44% to 80%) was lower than in-laboratory comparison of actual surface water (low concentration was from 66% to 79% and higher concentration was from 71% to 100%). The difference between domestic and imported analyzers was not significant. It was also found that there was difference between effective data rate and accounting of ±20% relative deviation in continuous online monitoring data. The difference was significant between different analyzers while it was not significant between domestic and imported analyzers.