冷原子吸收测定水质总汞的方法改进

Optimization of determination of total mercury in water by cold atomic absorption method

改进水质总汞的检测条件,提高检测效率。对比近沸保温法和煮沸法对样品的消解程度,以加标回收率和精密度等为指标,改进校准曲线的配制方法。煮沸法比近沸保温法对样品的消解程度高,且用时短;以HJ 597—2011中稀释液和1%HNO_(3)配制校准曲线均可满足质控要求。水质样品的消解建议优先选用煮沸法进行前处理,用时短且消解程度高;校准曲线可直接以1%盐酸将有证标准物质进行稀释后使用。检测采用冷原子吸收全自动测汞仪,水样经前处理后直接上机测定,在线加入氯化亚锡,反应密闭,安全高效。

Improve the detection conditions of total mercury in water quality and increase the detection efficiency.Compare the degree of digestion of the sample by the near-boiling heat preservation method and the boiling method,and improve the preparation method of the calibration curve based on the recovery rate and precision of the standard addition.The result showed that the boiling method has a higher degree of digestion than the near-boiling heat preservation method and takes a shorter time;the calibration curve prepared with the HJ 597—2011 medium dilution and 1%HNO_(3)can meet the quality control requirements.For the digestion of water quality samples,it is recommended that the boiling method be preferred for pretreatment,which takes a short time and has a high degree of digestion.The calibration curve can be used directly after diluting certified reference materials with 1%hydrochloric acid.The cold atomic absorption automatic mercury measuring instrument is used for detection.The water sample is directly tested on the machine after pretreatment,and stannous chloride is added online.The reaction is airtight,safe and efficient.