Voltammetric determination of vanadium with adsorptive preconcentration of the pyrocatechol violet complex

A sensitive stripping voltammetric procedure for trace measurements of vanadium in aqueous samples is reported. The method is based on the interfacial accumulation of the vanadium-pyrocatechol complex onto the hanging mercury drop electrode, followed by reduction of the adsorbed complex. The limit of detection is 0.1 nM vanadium after a 3 min collection with a stirred solution at pH 4.7. The procedure is selective with respect to other metals and has been applied in analysing various samples.     

Determination of chloride, nitrate, sulphate and total sulphur in environmental samples by single-column ion chromatography

The analytical performance characteristics of a single-column ion chromatography system are reported. The data were obtained by using conductivity detection as well as by an indirect ultraviolet technique. The method has been applied to the determination of Cl(-), NO(3)(-) and SO(4)(2-) in samples of rain, sewer water, and soil-pore water. Also described are two methods which allow ion Chromatographic analysis of CaS0(4)-extractable nitrate in soils, and total sulphur in soils, marine sediments and plant tissue.     

Determination of lead and antimony in firearm discharge residues on hands by anodic stripping voltammetry

When a person fires a gun, trace quantities of lead, antimony and barium are deposited on the hand. Detection of high levels of these trace metals on the hand of a suspect may therefore be significant evidence in an investigation. In this study conditions for the determination of lead and antimony in gunshot residues by anodic stripping voltammetry using a mercury-coated graphite electrode are established. A sample is collected by washing the hand in 1M hydrochloric acid. Lead is determined in a portion of this sample, with 1M hydrochloric acid as electrolyte. Antimony is determined in a second portion, with 4M hydrochloric acid as electrolyte. Prior separation or preconcentration steps are not required for either analysis. The procedure has been applied to samples obtained from five "normal" hands and five hands after they have fired a weapon.