Comparison between inductively coupled plasma-mass spectrometry and benchtop X-ray fluorescence performance for trace elemental exposure in rat tissues

Abstract

Background

Trace elemental toxicants induce health detriment in almost every organ system in the human body and account for a large amount of environmental and ecological environmental pollution. Traditionally, inductively coupled plasma mass spectrometry (ICP-MS) has been the gold standard for measuring elemental concentrations in biological tissues collected from toxicological and epidemiological studies. However, ICP-MS is often limited by its complexity, cost, and time-intensive nature.

Methods

This study investigates the feasibility of benchtop X-ray fluorescence (XRF) as an efficient alternative for trace elemental analysis in rat tissues, offering comparable quantification capabilities with enhanced operational simplicity. We conducted a comparative analysis using tissue samples from multiple rat organs, including stomach, eyes, and liver.

Results

The elemental concentrations of Arsenic (As), Cadmium (Cd), Copper (Cu), Manganese (Mn), and Zinc (Zn) were measured using both ICP-MS and a high-powered benchtop XRF (Epsilon 4, Malvern Panalytical). Our findings demonstrated strong linear regression correlations between the two methods: As (R² = 0.86), Cd (R² = 0.81), Cu (R² = 0.77), Mn (R² = 0.88), and Zn (R² = 0.74). The overall Pearson correlation coefficient was r = 0.95 (p ≤ 0.05), indicating high concordance between the mean concentrations obtained from ICP-MS and benchtop XRF. The median minimum detection limits for the elements were 0.12 µg/g, with specific limits for Cd (0.0042 µg/g), Cu (0.040 µg/g), Zn (0.12 µg/g), As (0.25 µg/g), and Mn (0.35 µg/g) over a 7.5-minute measurement period. Bland-Altman analysis revealed high agreement between the two methods, particularly for As, Cu, and Mn.

Conclusion

These results suggest that both ICP-MS and benchtop XRF are viable for elemental quantification in organ tissues, with benchtop XRF being more practical for low-mass samples. This study shows benchtop XRF's potential for high-throughput, accurate trace element analysis in biological samples, broadening its use in environmental and toxicological research.

Synopsis

Human and ecological tissues of varying compositions and densities can be measured effectively using benchtop X-ray fluorescence