Research Analytical Service Australia, North Epping, NSW, 2121, Australia.
Anal Sci. 2021 Aug 10;37(8):1181-1184. doi: 10.2116/analsci.20N035. Epub 2021 Jan 15.
This study demonstrated the signal enhancement interference from soluble iron (Fe) during mercury (Hg) determination in water by cold vapor atomic absorption spectrometry (CV-AAS) using sodium borohydride (NaBH) as reductant. In the presence of 50 mg L soluble Fe, Hg values will be overestimated by around 25%. The reason for the Hg signal enhancement is still unclear, but it is speculated to be attributable to the catalyst function for the equilibrium reduction reaction between Hg and BH from the atomic Fe formed at the same time. Using the matrix matching calibration standards prepared in 50 mg L Fe solution, the problem of Hg overestimation could be minimized. This study also indicated that stannous chloride (SnCl), another common reductant for Hg analysis, does not suffer from the overestimation problem from soluble Fe in the presence of NaBH.
本研究表明，在使用硼氢化钠（NaBH）作为还原剂的冷蒸气原子吸收光谱法（CV-AAS）测定水中汞（Hg）时，可溶性铁（Fe）会产生信号增强干扰。在存在 50mg/L 可溶性 Fe 的情况下，Hg 值将被高估约 25%。Hg 信号增强的原因尚不清楚，但据推测，这归因于同时形成的原子 Fe 对 Hg 与 BH 之间平衡还原反应的催化作用。使用在 50mg/L Fe 溶液中制备的基体匹配校准标准品，可以将 Hg 高估的问题降到最低。本研究还表明，在有 NaBH 的情况下，另一种常用的 Hg 分析还原剂氯化亚锡（SnCl）不会受到可溶性 Fe 的高估问题的影响。
