Sensitized spectrophotometric determination of trace Hg(II) in benzalkonium chloride media

A sensitized and convenient determination of trace Hg(II) with HgI42- complex in benzalkonium chloride media has been studied. The UV-VIS spectrum of HgI42- complex in benzalkonium chloride solution had higher sensitivity and reproducibility than that in aqueous solution. The HgI42- complex in benzalkonium chloride media was very stable at pH 10.0 and could be quantitatively complexed if I- was added to the sample solution more than 17 times the moles of Hg(II). The optimum concentration of benzalkonium chloride was 0.07%. The calibration curve of HgI42- complex with good linearity (R-2 = 0.9963) was obtained in 0.07% benzalkonium chloride media. The detection limit was 1.8 x 10(-8) M. Recovery yields of Hg(II) in spiked real and synthetic samples were mostly above 95%. Based on the experimental results, this proposed technique could be applied to the rapid and simple determination of trace Hg(II) in real samples. (C) 2002 Elsevier Science B.V. All rights reserved.