原子荧光光谱法测定玉米中汞

Atomic Fluorescence Spectrometry Determination of Mercury in Corn

采用微波消解法消解玉米样品，利用氢化物发生-原子荧光光谱法测定玉米中汞。研究并优化了载气及屏蔽气体的流量、硼氢化钾的浓度、灯电流、共存离子的干扰和消除等试验条件。荧光强度与汞的质量浓度在20ug·L^-1范围以内呈线性关系，方法的检出限（3S／N）为0．02ug·L^-1。应用此法分析了5份玉米试样，以标准加入法做回收率试验，回收率在90．0％～102.5%之间，相对标准偏差（n=10）小于4%。

HG-AFS was applied to the determinations of mercury in corn with microwave assisted sample digestion. The flow rates of carrier gas and shielded gas, concentration of potassium borohydride, electrical current of lamp, and interferences of the coexisting ions were studied and optimized. Linear relationship between the fluorescence intensity and mass concentration of Hg was found in the range within 20ug · L^-1, with detection limit of 0. 02ug· L^-1. The proposed method was applied to the analysis of 5 com samples, and values of recovery found by standard addition method were in range of 90. 0% to 102.5%, with values of RSD＇s （n= 10） less than 4%.