Measurements of methylmercury, ethylmercury, and inorganic mercury species in a whole blood standard reference material: SRM 955c—Toxic Elements in Caprine Blood

Abstract

Trace elemental speciation analysis is assuming more critical importance in nutritional and toxicological assessments, and despite the necessity to quantitatively differentiate elemental species in environmental and clinical samples, there are a limited number of reference materials suitable for this purpose. A whole blood certified reference material, SRM 955c Toxic Elements in Caprine Blood was developed for the determination of toxic metals in whole blood including mercury. The certification of methylmercury, ethylmercury, and inorganic mercury was carried out by triple spike speciated isotope dilution inductively coupled plasma mass spectrometry (TS-SID-GC/ICP-MS) and represents the first whole blood material certified for three mercury species. The certified values (±expanded uncertainty) of methylmercury, ethylmercury, inorganic mercury and total mercury in SRM 955c are 4.5 ± 1.0 µg L⁻¹, 5.1 ± 0.5 µg L⁻¹, 9.0 ± 1.3 µg L⁻¹, and 17.8 ± 1.6 µg L⁻¹ respectively.