改进氧瓶燃烧—氢化物发生原子荧光法测定淀粉中微量汞

DETERMINATION OF TOTAL MERCURY BY MODIFIED OXYGEN FLASK COMBUSTION-HYDRIDE GENERATION ATOMIC FLUORESCENCE SPECTROMETRY

用连续通O2、连续排放燃烧废气及采用吸收液吸收被测组分的改进氧瓶燃烧法处理淀粉试样,用氢化物发生原子荧光光谱法测定淀粉中的汞含量。当通O2量为300mL/min时,1.5g淀粉试样在10min内可完全燃烧。经装有冷却的10mL含0.5g/L(NH4)2S2O8的(5+95)HNO3溶液将汞氧化吸收为Hg2+后排出废气,制成的汞试液用氢化物发生原子荧光光谱法测定。汞的回收率为91.0%～95.5%,相对标准偏差5.1%。当相对误差在±5%时,500倍的Zn2+、Cd2+,300倍的Pb2+,100倍的As(Ⅲ)、Sb(Ⅲ)、Bi(Ⅲ)、Ge(Ⅳ)、Se(Ⅳ)不干扰测定。改进的氧瓶燃烧法为处理试样量大的有机物中痕量组分测定提供了一种简单、快速、廉价的新方法。

The determination of total mercury in starch by modified oxygen flask combustion -hydride generation atomic fluorescence spectrometry with continuously inlet O5 and let exhaust gas and absorb Hg with absorbent solution. When inlet O2 with 300 mL/min, 1.5 g starch can be burned completely. After absorb and oxygenate mercury into Hg^2＋ with refrigerant 10 mL 0.5 g/L （ NH4 ） 2 S2 O8 （5 ＋ 95）HNO3 solution,the exhaust gas was let. The Hg^2＋ sample solution was determined with hydride gdneration atomic fluorescence spectrometry. The recovery were in the range of 91.0% - 95.5% , the RSD is 4.8% （ n = 11 ） . When the relative error is ＋ 5 % ,the determination was not disturbed in 500 times Zn^2＋ ,Cd^2＋ ,300 times Pb^2＋ , 100 times As（ Ⅲ ） ,Sb（ Ⅲ ） ,Bi（ Ⅲ ） ,Ge（ Ⅳ ） ,Se（ Ⅳ ）. The modified oxygen flask combustion provied a new methed in the more amount organic sample with simply,rapidly and low-costly.