This report describes the analysis of blood serum using standard quantitative calibration with aqueous standards. Viscosity effects of the blood serum solutions were corrected using scandium (361.384 nmionic line) as an internal standard. Major, minor and trace elements were determined in a single analysis.
A major element in blood serum is sodium, which is an easily ionized element (EIE) and has been reported to cause ionization interference when present in reasonably high levels. Ionization interference tends to cause a reduction in signal intensity with increasing concentration of EIE and http://www.varian.com INSTRUMENTS AT WORK 2 the effect is prominent at interferent concentrations at or above 100 mg/L. The atomic lines of Na, K and to a lesser extent Ca (422.673 nm) exhibit signal enhancement with increasing concentrations of EIE. The effect can be easily minimized or eliminated on a radially-viewed ICP-AES by adjusting the viewing height. For the more sensitive axially-viewed ICP-AES, many reports of interferences due to EIE have been described3-5. Reducing the nebulizer pressure and increasing the RF power has been reported to reduce ionization interference on the axially-viewed ICP-AES3. Scandium as an internal standard has also been found to compensate for part of the signal depression