Quantitative determination of barium in human blood by ion chromatography: Method development and case application in barium intoxication

Barium is an alkaline earth metal widely used in various industrial applications and as a rodenticide. Barium poisoning primarily occurs through occupational exposure or deliberate ingestion. Water-soluble barium compounds, such as barium chloride and barium carbonate, can induce severe neurological, cardiovascular, and muscular toxicity. While atomic absorption spectrometry (AAS), inductively coupled plasma-optical emission spectrometry (ICP-OES), and inductively coupled plasma-mass spectrometry (ICP-MS) are commonly used for barium analysis, this study developed and validated an ion chromatography (IC)-based method utilizing a 250 μL sample loop for the quantitative analysis of barium in blood and qualitative analysis of forensic evidence. The method was validated with a limit of detection (LOD) of 0.03 mg/L and a limit of quantification (LOQ) of 0.10 mg/L. Intra-day and inter-day precision (RSD) ranged from 1.9% to 5.3% and 1.8% to 5.1%, respectively. Intra-day and inter-day accuracy (bias) ranged from 92.1% to 98.9% and 93.2% to 97.1%, respectively, with a linearity of R² > 0.99. The method was successfully applied to a suicide case involving barium ingestion, where barium was detected at 1.66 mg/L in the heart blood, as well as in the gastric contents and crime scene evidence. This IC-based approach provides a reliable alternative for barium determination in forensic toxicology.