Screening trace elements and electrolytes in serum by inductively-coupled plasma emission spectrometry.

This rapid, accurate procedure for trace elements and electrolytes in serum requires little sample preparation: to 1 mL of serum a single reagent is added that contains trichloroacetic and hydrochloric acids for protein precipitation, hydroxylamine sulfate for iron reduction, and yttrium as the internal standard. After centrifugation, the supernates are directly analyzed for Na, K, Mg, Ca, Pi, Fe, Cu, and Zn by inductively-coupled plasma emission spectrometry. The CVs were respectively 7.9%, 8.4%, 8.6%, 10.0%, 9.0%, 9.4%, 9.0%, and 9.0% for five assays of National Institute of Standards and Technology Standard Reference Material (SRM) no. 1598, Bovine Serum. Analytical recoveries ranged from 92% to 107% for both SRM 1598 and commercial control serum.