【摘要】 基于美国环境保护局(U.S.Environmental Protection Agency,USEPA)1631方法,自制双柱热脱附装置,以国产AF-610B型原子荧光仪为检测器,搭建吹扫-金柱捕集-(双柱)热脱附-冷原子荧光系统,用于测定环境样品中的总汞。对吹扫流速、吹扫时间和尾吹流速等实验参数进行了优化。双柱热脱附装置的脱附效率为99%—100%。在最优测定条件下,仪器检出限为5.0pg,海水测定的方法检出限为0.50ng/L,土壤、沉积物和红树样等固体样品测定的方法检出限为1.0ng/g。采用基底加标回收率法和参考样,验证了该系统的准确可靠性。结果表明,海水、土壤、沉积物和红树植物组织等样品的基底加标回收率均符合USEPA的限定范围,土壤参考样(ESS-4)和近海海洋沉积物参考样(GBW07314)的测定结果在参考值的可控范围内。该系统可满足环境样品中总汞测定的要求。更多还原

【Abstract】 Based on U.S.Environmental Protection Agency(USEPA) Method 1631,a detection system was established for the determination of total Hg in water,sediment,soil and biota samples with the devices of purge-trap,and cold vapor atomic fluorescence spectrometer(CVAFS).The system equipped with a lab-made dual-trap thermal desorption set-up and an AF-610B CVAFS instrument.The parameters including flow rates of purging gas and tail gas,as well as the purging time,were optimized.The desorption efficiencies of the dual-trap thermal desorption were ranged from 99%to 100%.Under the optimized conditions,the instrumental detection limit was 5.0 pg,and the detection limits for seawater and solid sample(soil,sediment and plant sample) were 0.50ng/L and 1.0ng/g,respectively.The recoveries of matrix pike samples were in the ranges regulated by USEPA Method 1631,and the results of soil certified reference material(CRM)(ESS-4) and sediment CRM (GBW07314) were within the 95%confidence interval values.更多还原