Measurement of the Trace Elements Cu, Zn, Fe, and Mg and the Ultratrace Elements Cd, Co, Mn, and Pb in Limited Quantity Human Plasma and Serum Samples by Inductively Coupled Plasma-Mass Spectrometry

In public health studies limited volumes of blood are often collected and stored for future hypothesis testing. Archived samples are irreplaceable and therefore it is valuable to develop analytical techniques that require minimal sample volume. This work describes the measurement of trace elements Mg, Cu, Fe, Zn and ultratrace elements Cd, Co, Mn, Pb in limited quantity (150 μL) human serum or plasma samples. Samples were digested using a hotblock and analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The analytical method was evaluated using a quadrupole (Q) and sector field high resolution (SF) instrument to analyze trace elements in Seronorm quality control serum material. The method was used to analyze 1888 blinded human plasma samples which were archived for the National Cancer Institute from the Nutrition Intervention Trial in Linxian China. The inductively coupled plasma method was capable of accurately analyzed limited quantity samples of human serum and plasma for the trace elements Mg, Cu, Fe Zn and the ultra trace elements Co, Mn and Pb. The concentration of Cd in human plasma samples was below the level of detection for 75% of the samples analyzed.