应用DMA-80直接汞分析仪快速测定了土壤、大米、人发、垃圾、污水等8类样品中汞的含量。按样品性质取适量样品置于镍质样品舟或石英样品舟内,在150 ℃~300 ℃(约30~300 s)将样品烘干后,在800 ℃~950 ℃温度下分解并氧化(约180~420 s)。所生成的氧化汞进入催化炉催化还原为汞蒸气,再经过汞齐化器使汞蒸气被选择性捕集并汞齐化,加热使汞解吸,由载气引入光学池在波长253.7 nm处进行原子吸收光谱法检测。用标准曲线法定量,按所选择的测定条件测定了2种标准样品(GSS-3土壤标准样品和GSD-9水系沉积物标准样品)中的汞含量,测定值与认定值相符,测定值的相对标准偏差(n=5)依次为3.2%,5.4%。用此仪器测定了污泥、土壤、垃圾浸出液,生活污水和河水等样品中的汞含量,测定值与常规原子荧光光谱法的测定值一致。

DMA-80 direct mercury analyzer was applied to rapid determination of total mercury in 8 kinds of samples, including soil, rice, human hair, gabbage, waste water and etc. An appropriate amount of solid or liquid sample was placed in the nickel or quartz sample boat, dried at 150 ℃-300 ℃ for 30-300 s, selected according to different properties of the sample; mercury in the sample was oxidized to HgO at 800 ℃-950 ℃ for 180 to 420 s. The HgO was reduced to Hg0 vapor in the catalytic reductor, and the Hg0 vapor was amalgamated and trapped selectively in the amalgamator, and after desorption pure mercury vapor was carried over to the optical cell for AAS determination at the wavelength of 253.7 nm. Standard curve was used for quantification. Two standard samples (GSS-3 and GSD-9) was analyzed by the analyzer under the optimized conditions, giving values of ∑Hg contents in consistency with the certified values, with values of RSD′s (n=5) of 3.2% and 5.4% respectively. Contents of total mercury in samples of sludge, soil, gabbage extracts, domestic sewage, and river water were also determined by the analyzer, giving results checked quite well with those obtained by conventional AFS.