A simple and high-throughput ICP-MS method for the determination of 46 elements in urine: Biomonitoring of occupational exposure in automotive workers

Monitoring urinary metal concentrations is crucial for assessing occupational exposure and associated health risks. Inductively coupled plasma mass spectrometry (ICP-MS) is widely considered the method of choice for multi-element analysis due to its high sensitivity, low detection limits, and broad dynamic range. This study presents a simple and rapid ICP-MS method for the simultaneous determination of 46 elements in urine, utilizing 2 % nitric acid and 1.5 % ethanol (v/v) for sample pretreatment. This approach effectively mitigates matrix effects and carbon-based interferences. The method demonstrated excellent linearity (coefficient of determination, R² ≥ 0.9985), precision (relative standard deviation, RSD < 8 %), and accuracy (recoveries 80–120 %). The method was applied to analyze 268 urine samples from automotive manufacturing workers. Several elements of occupational relevance, including Nickel (Ni), tungsten (W), molybdenum (Mo), titanium (Ti) and Cadmium (Cd), as well as essential elements such as iron (Fe), copper (Cu), and zinc (Zn), were elevated compared with general population references, indicating complex multi-metal exposure profiles. This work provides a validated and efficient tool for occupational biomonitoring and delivers valuable elementomic data to support exposure assessment, workplace interventions, and future research on the health effects of multi-metal exposure.