Determination of Mercury in Fly Ash by Flameless Cold Vapour Atomic Absorption Spectrometry Using Hydride Generator

Abstract

An accurate, reliable and sensitive method has been developed for the
determination of mercury in fly ash. Hydrofluoric acid reacts with fly ash
and releases mercury,  which is converted into non-volatile form by reacting
with nitric acid and perchloric acid. The elemental mercury formed after
reduction with sodium borohydride (NaBH₄) is determined by flameless
atomic absorption spectrometry using hydride generator. The fly ash sample
analyzed was received from National Council for Cement and Building
Materials (NCCBM), which will be used as reference material in future.
The validity of the method has been established by comparing the results
obtained from NIST certified reference material 1633(b). The standard
deviation has been calculated by analyzing ten replicates of both fly ash
samples.