A comparison of Inductively Coupled Plasma Mass Spectrometry with Electrothermal Atomic Absorption Spectrophotometry for the Determination of Trace Elements in Blood and Urine from non Occupationally Exposed Populations

Abstract

Quadrupole Inductively coupled plasma mass spectrometric (QICP-MS) and electrothermal atomic absorption spectrophotometric (ETAAS) methods for the determination of Pb and Cd in whole blood and Al, Cd, Co and Ni in urine were compared. Simple sample pretreatments were used for both instrumental techniques. Urine samples were diluted with either Millipore water or dilute HNO3, while blood samples were diluted with a solution containing either 0.14M NH3 or 0.03 M NH3, 0.05% EDTA and 0.05% Triton X-100 in Millipore water. Scandium, yttrium and indium were used as internal standards for ICP-MS measurements and (NH4)2HPO4 as a chemical modifier for the determination of Pb and Cd by ETAAS. For ICP-MS analysis, pneumatic nebulization was used for introduction of urine samples and flow injection for introduction of blood samples. Matrix matched standards were used for all calibrations and methods were validated by analyzing reference materials and samples from external quality assurance programmes. Concentrations of the listed metals were determined in blood and urine samples obtained from a healthy non occupationally exposed population and reference samples, using both instrumental techniques. The study group (n = 90) was randomly selected from a study population (n = 220) recruited from three regions considered representative of the environment encountered by the majority of the United Kingdom population. Males and females were equally represented and ranged in age from 17-65 yrs. The correlation between results obtained by the two techniques was good for all elements measured, ranging from r = 0.88 for Co in urine to r = 0.99 for both Pb and Cd in blood.