Development and Validation of a High-Performance Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry Method for the Simultaneous Determination of Arsenic and Mercury Species in Human Urine

The simultaneous determination of arsenic and mercury species in human urine is critical for clinical diagnostics and therapeutic monitoring because it reduces the costs, time, and consumption of samples. This study proposes a method of utilizing high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) for the concurrent analysis of arsenic and mercury species in urine samples. The separation was performed using a Hepu AR 5 μm C18 (250 × 4.6 mm) column, employing a mobile phase composed of 0.1% L-cysteine, 5 mM NH4H2PO4, and 4 mM tetrabutylammonium hydroxide (TBAH). The samples were diluted with water, and matrix interference was reduced through the application of a kinetic energy discrimination (KED) mode. Calibration curves for four arsenic species and three mercury species exhibited strong linearity within the range of 1–20 μg L−1, with correlation coefficients (r) above 0.999. The limits of detection (LOD) ranged from 0.030 to 0.086 μg L−1, while the limits of quantitation (LOQ) were observed to range from 0.10 to 0.29 μg L−1. The spiking recoveries for all species varied from 87.0% to 110.3%, and the intra-day and inter-day relative standard deviations (RSD) were determined to be 1.1–6.0%, and 0.8–9.2%, respectively. These results indicate that the developed method achieves high precision, accuracy, and suitability for clinical applications, offering valuable insights for the diagnosis and treatment of heavy metal exposure.