大气环境降水监测的质量控制方法

根据《环境监测质量管理规定》、《江苏省环境监测质量管理实施细则》及环境监测技术规范的要求,探讨了降水监测采样、样品保存技术、实验室分析的质量控制方法。采用不同采样方法、不同采样器同时采集15场降水,其降雨量、电导率、pH值的比对监测结果合格率均大于90%。经试验,降水各组分有效保存时间不同,其中NO_3~-,NH_4~+为3 d;F~-,Cl~-,SO_4~(2-)为14d;K~+,Na~+,Ca~(2+),Mg~(2+)为30 d。选择2家实验室对降水样品、空白样品、标准样品同时测试,结果显示,空白测定结果均低于方法检出限,标准曲线相关性系数r≥0.999 0,测定结果的相对标准偏差为1.4%~5.9%(n=6),加标回收率为89.8%~106%,标准样品的分析结果均合格。该方法能保证降水监测结果准确、可靠,满足HJ/T 165-2004《酸沉降监测技术规范》的要求。

Quality Control Method of Precipitation Monitoring in Atmospheric Environment

The quality control methods of precipitation monitoring sampling,sample preservationand laboratory analysis were discussed according to the environment monitoring technical specification and standard methods such as Environmental Monitoring Quality Management Regulations and Jiangsu Province Environmental Monitoring Quality Management Implementation Details. The qualified rate of detection of rainfall,conductivity and pH monitoring was higher than 90% in 15 precipitation samples by different sampling methods and equipments. The experimental results showed that the retention time were 3 d for nitrate and ammonium,14 d forfluoride,chloride and sulfate ions,30 d for the potassium, sodium,calcium and magnesium in precipitation sample. The comparison experiment was carried out in two laboratories. The blanks were below the method detection limits,standard curve correlation coefficients were not less than 0.999 0. The relative standard deviations of detection results were 1.4%–5.9% (n=6), the recoveries of the target were 89.8%–106%. The results of certified standard sample were qualified. This method can ensure the precipitation monitoring results accurate and reliable, so it can meet the requirements of Acid Deposition Monitoring Technology Standard.