Sequential voltammetric determination of chromium, thallium, cadmium, lead, copper and antimony in saline hemodialysis concentrates using electrolyte pH gradient

Paulo C Nascimento,Cristiane L Jost,Alexandre B Schneider,Leandro M De Carvalho,Denise Bohrer

doi:10.1590/s0103-50532011000500003

Paulo C Nascimento, Cristiane L Jost + Show 3 more

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https://doi.org/10.1590/s0103-50532011000500003

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Abstract

The sequential voltammetric determination of chromium, thallium, cadmium, lead, copper and antimony in dialysate concentrates (DCs), is presented herein. Chromium was quantified by adsorptive cathodic stripping voltammetry and thallium, cadmium, lead, copper and antimony were assayed by anodic stripping voltammetry. The novel method developed to test these samples exploits the effect of electrolyte pH gradient on voltammetric response. The limits of detection (LOD) ranged from 0.03 µg L-1 for cadmium to 0.27 µg L-1 for copper. Recoveries from spiked samples were 92.0-117.5%. This method was applied to the analysis of commercial DCs, where the investigated metals were found in some samples at concentrations between 0.16 µg L-1 for antimony and 140.00 µg L-1 for copper. Interferences and the reference method are discussed

Highlights

Hemodialysis has been successfully used since the mid 1900s
In previous studies of the salts used to make up dialysate concentrates (DCs), we found the presence of natural contamination from heavy metals[2] as well as the contamination of some commercial DCs by cadmium, thallium, lead[3] and copper.[4]
Sequential voltammetric determinations of chromium, thallium, cadmium, lead, copper and antimony were based on the effect of the supporting electrolyte pH gradient on both the adsorption/desorption process of Diethylenetriaminepentaacetic acid (DTPA) on the mercury electrode and the DTPA complexing ability towards the analytes present in DCs

Summary

Introduction

Hemodialysis has been successfully used since the mid 1900s J. Kolff used the first dialysis machine in 1943)[1] to increase the survival time of dialysis patients. The fluid used during dialysis therapy (dialysate) is prepared just before each hemodialysis session by mixing hemodialysis water (HW) with commercially available saline hemodialysis concentrates (DCs). HW and DCs are produced according to strict quality control regulations to avoid chemical and microbiological contamination. The maximum permissible contaminant levels in HW are set by national and international standards, such as the Association for the Advancement of Medical Instrumentation (AAMI) recommended practices for

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