Non-chromatographic screening method for the determination of mercury species. Application to the monitoring of mercury levels in Antarctic samples.

A simple non-chromatographic method for the determination of mercury (Hg(2+)), methylmercury (MeHg(+)), dimethylmercury (Me(2)Hg), and phenylmercury (PhHg(+)) employing atomic fluorescence spectrometry (AFS) as detection technique was developed. Mercury species showed a particular behavior in the presence of several reagents. In a first stage SnCl(2) was employed for Hg(2+) determination; in a second step, [Hg(2+)+PhHg(+)] concentration was determined using SnCl(2) and UV radiation. MeHg(+) decomposition was prevented adding 2-mercaptoethanol. In a third stage, [Hg(2+)+PhHg(+)+MeHg(+)] concentration was determined using K(2)S(2)O(8). Finally, the four species were determined employing NaBH(4). Reagents concentration and flow rates were optimized. The extraction technique of mercury species involved the use of 2-mercaptoethanol as ion-pair reagent. The limits of detection for Hg(2+), PhHg(+), MeHg(+), and Me(2)Hg were 1, 40, 68, and 99 ng L(-1) with a relative standard deviation of 1.5, 3.1, 4.7 and 5.8%, respectively. Calibration curve was linear with a correlation factor equal to 0.9995. The method was successfully applied to the determination of the mercury species in two Antarctic materials: IRMM 813 (Adamussium colbecki) and MURST-ISS-A2 (Antarctic Krill). Copyright (c) 2010 Elsevier B.V. All rights reserved.