Method validation for the quantification of As, Cd, Hg and Pb in blood by ICP-MS for monitoring purposes

Abstract

Medical laboratories dedicated to the quantification of trace and ultra trace elements in human biological fluids should be accredited according to the ISO standards 15189 : 2007. The use of validated methods for elements determination in blood becomes crucial for laboratories involved in medical analysis. The toxicological importance of As, Cd, Hg and Pb is well known and internationally recognized. These trace elements may be accumulated in human body through the exposure to pollutants in the environment as a result of uncontrolled anthropogenic activities. The internal levels of these elements can be estimated by the collection of blood samples from groups of selected population (biomonitoring).

A fast and simple method to allow routine analysis of hundreds of blood samples was developed and fully validated. Arsenic, cadmium, mercury and lead were quantified in blood by quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS). A high throughput open digestion procedure was applied. Trueness, repeatability, within-laboratory reproducibility and standard measurement uncertainty were evaluated as method characteristics. The limits of quantification of the method were: 2.3 (As) μg l⁻¹, 0.10 (Cd) μg l⁻¹, 0.66 (Hg) μg l⁻¹ and 0.56 (Pb) μg l⁻¹. The method can be applied in the following ranges of concentration: 5–120 (As) μg l⁻¹, 0.5–32 (Cd) μg l⁻¹, 2.5–160 (Hg) μg l⁻¹, 10–640 (Pb) μg l⁻¹.