Direct and simultaneous determination of Ca, Cl, K, Mg, Na, and P in human urine by inductively coupled plasma optical emission spectrometry

摘要

The concentrations of Ca, Cl, K, Mg, Na, and P in urine are generally required in clinical tests. This paper describes the direct and simultaneous determination of these species in human urine using a simple and quick procedure based on inductively coupled plasma optical emission spectrometry (ICP-OES). The samples, obtained from the Clinical Hospital (HC) of the University of Campinas (UNICAMP), Campinas, Brazil, were conditioned in nitric acid and directly introduced into the ICP-OES, using robust conditions. The limits of detection (3 σ) obtained for the analytes were 3 mg L~(-1) (Ca), 175 mg L~(-1) (Cl), 21 mg L~(-1) (K), 0.8 mg L~(-1) (Mg), 65 mg L~(-1) (Na), and 14 mg L~(-1) (P). The precision (RSD) was better than 5%. Accuracy was evaluated by comparing the values obtained by ICP-OES with those from standard spectrophotometric methods employed at the HC of UNICAMP. The results obtained showed that the proposed method is very promising for routine urine analysis since it allows fast and multielement determinations in the same sample aliquot in comparison to several other procedures normally used for this purpose.