Determination of Se,As,Cu,Pb,Cd,Zn and Mn by anodic and cathodic stripping voltammetry in marine environmental matrices in the presence of reciprocal interference.Proposal of a new analytical procudure

摘要

Arsenic(III),selenium(IV),copper(II),lead(II),cadmium(II),zinc(II) and manganese (II) have been determined in environmental matrices by differential pulse cathodic (DPCSV) and anodic (DPASV) stripping voltammetry.The voltammetric measurements were carried out using a conventional three-electrode cell and the ammonia-ammonium chloride buffer (pH 9.4) as the supporting electrolyte.The analytical procudure was verified by the analysis of the standard reference materials:Sea Water BCR-CRM 403;Lagarosiphon Major BCR-CRM 060;and Cod Muscle BCR-CRM 422.The precision,expressed as relative standard deviation,and the accuracy,expressed as relative error,were,in all cases,lower than 5%;the detection limits,for each element in the experimental conditions employed,was aproximately 10~(-9) M.The standard addition technique significantly improved the resolution ofthe voltammetric method,even inthecase of very high metal concentration ratios.