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JAAS

Innovative research on the fundamental theory and application of spectrometric techniques.



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Paper

J. Anal. At. Spectrom., 1997, 12, 611 - 616, DOI: 10.1039/a608550d

At-line Determination of Mercury in Process Streams Using Atomic Fluorescence Spectrometry

NOEL K. BRAHMA, WARREN T. CORNS, PETER B. STOCKWELL, LES EBDON and E. HYWEL EVANS

Atomic fluorescence spectrometry (AFS) has been coupled with vapour generation sample introduction for the at-line determination of mercury in concentrated sulfuric acid production streams. Matrix and heat effects were overcome by the use of discrete sample injection techniques. A sample collection and pre-treatment manifold is described in combination with permanganate oxidation and SnCl2 reduction chemistries for coupling with a fully automated instrument. Continuous monitoring of single grab samples of concentrated sulfuric acid over periods of 24 and 15 h resulted in precisions of 5.8 and 8.9% RSD and mean mercury concentrations of 1.11 and 1.08 g g-1, respectively, compared with 1.2 and 0.95 g g-1 obtained by a laboratory based method. The application of the instrument in on-site trials at a sulfuric acid plant is described. The mercury concentration in sulfuric acid was monitored continuously over a period of 10 d without intervention and showed excellent agreement with results of laboratory analyses performed over the same period.