Abstract Background Accurate quantification of essential trace elements and toxic heavy metals in biological matrices is crucial for diagnosing deficiencies, monitoring treatment, and assessing exposure to environmental contaminants. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) has become a widely recognized method for precise and reliable quantification of a broad spectrum of elements in complex biological samples. This study aims to evaluate the performance of an ICP-MS method for the simultaneous determination of essential trace elements and heavy metals in human whole blood, plasma, and packed red blood cells (RBC). Methods Whole blood, plasma, and packed RBC samples were processed with specific diluents for ICP-MS analysis. Tetramethylammonium hydroxide was used for iodine dilution, while ammonium hydroxide was used for all other elements. The samples were analyzed using the Agilent 7850 ICP-MS system with MassHunter software. Internal standards were continuously introduced throughout the analysis to correct for matrix effects, signal drift, and other potential sources of variation. A total of eight elements were targeted: five essential trace elements (zinc, copper, selenium, magnesium, and iodine) and three heavy metals (lead, mercury, and arsenic). Zinc, copper, and selenium were analyzed in both plasma and RBC samples, magnesium in RBCs, iodine in plasma, and lead, mercury, and arsenic in whole blood. Analytical precision was assessed through replicate measurements within-run and over 5 days, evaluating intra- and inter-day variability. The limit of quantification (LOQ) was determined using low-concentration standards for each element. A method comparison study was conducted using clinical patient samples analyzed with another ICP-MS method performed at a reference laboratory. Accuracy was further assessed by spiking patient samples with known concentrations of each element and calculating the recovery rates. Results Precision studies demonstrated that all analytes exhibited satisfactory intra- and inter-assay variability, with coefficients of variation (CV) consistently below 10%. The established LOQs for the analytes were as follows: 2 µg/L for mercury and arsenic, 1 µg/dL for lead, 10 µg/L for iodine, 20 µg/L for selenium, 10 µg/dL for copper, 30 µg/dL for zinc, and 0.2 mg/dL for magnesium. Method comparison studies using patient samples revealed strong correlation with reference laboratory results, with bias values of less than 8% for trace elements and less than 11% for heavy metals analyzed. Qualitative analysis of the heavy metal concentrations showed perfect agreement (100%) between the ICP-MS method and the reference laboratory method for all three heavy metals. Spike and recovery studies showed recoveries ranging from 93% to 104%, confirming the method*s reliability across different sample types. Conclusion The ICP-MS method evaluated in this study offers a rapid, precise, and reliable approach for the simultaneous quantification of essential trace elements and toxic heavy metals in whole blood, plasma, and packed red blood cells. Our findings support the method*s potential utility in a wide range of clinical and research applications, particularly in detecting metal toxicity and managing trace element imbalances.
Alturkmani et al. (Wed,) studied this question.