Determination of trace level cadmium in SRM 3280 Multivitamin/Multielement Tablets via isotope dilution inductively coupled plasma mass spectrometry.

Cadmium was quantified at 80.15±0.86 ng/g (mean±95% expanded uncertainty) in NIST SRM 3280 Multivitamin/Multielement Tablets, using isotope dilution mass spectrometry. The method described utilized various precipitation and solid-phase extraction separation methodologies to isolate Cd from Sn and Mo, present respectively, at 11.1±0.9 mg/kg and 70.7±4.5 mg/kg in the tablet matrix. This allowed for measurement of (111)Cd/(113)Cd and (111)Cd/(114)Cd isotope ratios using both quadrupole collision cell technology inductively coupled plasma mass spectrometry (Q-CCT-ICP-MS) and sector field (SF)-ICP-MS equipped with a desolvating nebulizer system to mitigate the MoO(+) and MoOH(+) molecular ion interferences that typically affect the envelope of Cd isotopes.