On-line determination of mercury(II) by membrane separation flow injection analysis.
A rapid and inexpensive gas-diffusion (GD) flow injection method for the on-line determination of Hg(II) in aqueous samples is described. The analytical procedure involves the injection of a Hg(II) sample into a 1.5M H(2)SO(4) carrier stream which is merged with a reagent stream containing 0.6% SnCl(2) and 1.5M H(2)SO(4). Under these conditions Hg(II) is reduced to metallic mercury which partially evaporates through a Teflon membrane into an acceptor stream containing 1.75x10(-4)M KMnO(4) in 0.3M H(2)SO(4). The decrease in the absorbance of the acceptor stream at 528nm corresponding to the absorption maximum of the permanganate anion can be related to the original concentration of Hg(II) in the sample. The method is characterized by a detection limit of 4mugl(-1) and a sampling frequency of 8h(-1). The flow system was successfully applied to the analysis of river samples spiked with Hg(II).
Amini
Nazanin
N
School of Chemistry, The University of Melbourne, Parkville, Vic. 3010, Australia.
Cardwell
Terence J
TJ
Cattrall
Robert W
RW
Morrison
Richard J S
RJ
Kolev
Spas D
SD