Nk. Brahma et al., AT-LINE DETERMINATION OF MERCURY IN-PROCESS STREAMS USING ATOMIC FLUORESCENCE SPECTROMETRY, Journal of analytical atomic spectrometry, 12(6), 1997, pp. 611-616
Atomic fluorescence spectrometry (AFS) has been coupled with vapour ge
neration sample introduction for the at-line determination of mercury
in concentrated sulfuric acid production streams. Matrix and heat effe
cts were overcome by the use of discrete sample injection techniques,
A sample collection and pre-treatment manifold is described in combina
tion with permanganate oxidation and SnCl2 reduction chemistries for c
oupling with a fully automated instrument, Continuous monitoring of si
ngle 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 conc
entrations of 1.11 and 1.08 mu g g(-1), respectively, compared with 1.
2 and 0.95 mu g g(-1) obtained by a laboratory based method, The appli
cation of the instrument in on-site trials at a sulfuric acid plant is
described, The mercury concentration in sulfuric acid was monitored c
ontinuously over a period of 10 d without intervention and showed exce
llent agreement with results of laboratory analyses performed over the
same period.