Uranium quantification in semen by inductively coupled plasma mass spectrometry

Area of Science:

• Environmental Science
• Toxicology
• Analytical Chemistry

Background:

• Human semen analysis is crucial for assessing exposure to environmental contaminants.
• Uranium exposure, particularly from depleted uranium (DU), is a concern for military personnel.
• Accurate quantification methods are needed to determine uranium levels in biological matrices.

Purpose of the Study:

• To develop and validate a method for uranium quantification in human semen.
• To assess uranium levels in semen samples from Gulf War veterans exposed to DU.
• To establish baseline uranium levels in control semen samples.

Main Methods:

• Inductively coupled plasma mass spectrometry (ICP-MS) was employed for uranium quantification.
• Semen liquefaction was performed without additives (chymotrypsin, bovine serum albumin) to prevent uranium contamination.
• Method validation included spiking experiments at various uranium concentrations (5, 50, 1000 pg/g) to determine accuracy and precision.

Main Results:

• The validated method demonstrated a low detection limit of 0.8 pg/g uranium in human semen.
• Spike recoveries ranged from 97-100%, with relative standard deviations (RSD) between 1.4-7%, indicating high precision and accuracy.
• Baseline uranium levels in control semen samples averaged 2.9 pg/g.
• Uranium concentrations in semen from DU-exposed veterans varied widely, from undetectable (<0.8 pg/g) to 3350 pg/g.

Conclusions:

• The developed ICP-MS method is sensitive and accurate for uranium analysis in human semen.
• Semen can serve as a biomarker for assessing uranium exposure, reflecting body burdens.
• The wide range of uranium levels in exposed veterans highlights individual differences in DU retention and exposure levels.