冷蒸气发生-原子荧光法测定海水中超痕量汞  

Determination of ultra-trace mercury in seawater by cold vapor generation atomic fluorescence spectrometry

作　　者：未敏 孟范胜 侯爱霞 WEI Min;MENG Fansheng;HOU Aixia(Beijing Haiguang Instrument CO.,LTD.,Beijing 101300,China)

机构地区：[1]北京海光仪器有限公司,北京101300

出　　处：《化学分析计量》2023年第9期63-67,共5页Chemical Analysis And Meterage

摘　　要：采用具有高稳定度汞灯漂移校准系统的原子荧光光度计作为检测器,在对原子荧光光度计的仪器和检测条件进行优化后,建立了以硫酸-过硫酸钾消解海水样品,冷蒸气发生-原子荧光法测定海水中超痕量汞的方法。在载气、辅助气、屏蔽气流量分别为200、100、500 mL/min,还原剂硼氢化钾浓度为0.05%(质量分数),载流为含有0.05%重铬酸钾(质量分数)的2%硫酸溶液(体积分数)的最佳分析条件下,汞的线性范围为0~0.25μg/L,相关系数为0.9997,检出限为0.0007μg/L。对汞质量浓度为(1.00±0.06)μg/L的海水标准物质进行6次平行测定,汞的相对标准偏差为2.95%,相对误差为-0.10%。对两种低汞含量海水样品进行6次平行测定,汞的质量浓度测定值分别为0.012、0.016μg/L,相对标准偏差分别为6.80%、4.70%,加标海水样品汞的回收率为86.67%~100%。该方法检测海水中的超痕量汞具有较高的准确性和稳定性。The atomic fluorescence photometer with a high stability mercury lamp drift calibration system was used as the detector,after the instrument and detection conditions of atomic fluorescence spectrometer were optimized,a method for the determination of ultra-trace mercury in seawater by cold vapor generation atomic fluorescence spectrometry was established with digested the seawater sample by sulfuric acid and potassium persulfate.Under the optimal analysis conditions that the flow rates of carrier gas,auxiliary gas and shielding gas are 200,100 and 500 mL/min respectively,the concentration of reducing agent potassium borohydride is 0.05%(mass fraction),and the carrier current is 2%sulfuric acid solution(volume fraction)containing 0.05%potassium dichromate(mass fraction),the linear range of mercury was 0-0.25μg/L with the correlation coefficient of 0.9997,the detection limit was 0.0007μg/L.The relative standard deviation for determination of mercury content in seawater reference materials was 2.95%(n=6)and the relative error was-0.10%.Two actual seawater samples containing ultra-trace mercutry were determined by this method,and the detection values of mercury were 0.012 and 0.016μg/L,withe the relative standard deviations of 6.80%,4.70%(n=6),respectively.The recovery rates of mercuty in seawater were 86.67%-100%.This method has high accuracy and stability for the determination of ultra-trace mercury in seawater.

关 键 词：海水 超痕量汞 原子荧光法 

分 类 号：O657.3[理学—分析化学]