title: Improved spectrophotometer evaluated.
mesh_terms: D002118:Calcium / Q000097:blood; D005069:Evaluation Studies as Topic; D006801:Humans; D008274:Magnesium / Q000097:blood; D013054:Spectrophotometry, Atomic / Q000295:instrumentation*
chemical_list: D008274:Magnesium; D002118:Calcium