Application of ICP-OES to the Determination of Barium in Blood and Urine in Clinical and Forensic Analysis

Exposure to barium (Ba) mostly occurs in the workplace or from drinking water, but it may sometimes be due to accidental or intentional intoxication. This paper presents a reliable, sensitive method for the determination of Ba in blood and urine: inductively coupled plasma optical emission spectrometry (ICP-OES) after microwave digestion of samples. The overall procedure was checked using Seronorm Whole Blood L-2, Trace Elements Urine and spiked blood and urine samples (0.5-10 µg/mL of Ba). The accuracy of the whole procedure (relative error) was 4% (blood) and 7% (urine); the recovery was 76-104% (blood) and 85-101% (urine). The limits of detection and quantification (Ba λ = 455.403 nm) were 0.11 and 0.4 µg/L of Ba, respectively; precision (relative standard deviation) was below 6% at the level of 15 µg/L of Ba for blood. This method was applied to a case of the poisoning of a man who had been exposed at the workplace for over two years to powdered BaCO3, and who suffered from paralysis and heart disorders. The concentrations of Ba, in μg/L, were 160 (blood), 460 (serum) and 1,458 (urine) upon his admission to the hospital, and 6.1 (blood) and 4.9 (urine) after 11 months (reference values: 3.34 ± 2.20 µg/L of Ba for blood and 4.43 ± 4.60 µg/L of Ba for urine).