Determination of Potassium by Dry Reagent Carrier Technology: A Multicentre Evaluation
| Autor: | Mary Burritt, K. Paschen, John G. Toffaletti, G. Weidemann, M. Cortes, H. R. M. Lang, Elisabeth Ramstetter, Robert Leinberger, W. Tritschler, P. Vogel, P. Hagemann |
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| Rok vydání: | 1993 |
| Předmět: |
Potassium
Sodium Clinical Biochemistry education chemistry.chemical_element Mineralogy Potassium Cation Sensitivity and Specificity chemistry.chemical_compound pH indicator Spectrophotometry medicine Humans Ammonium Valinomycin Chromatography medicine.diagnostic_test Spectrophotometry Atomic Biochemistry (medical) Reproducibility of Results General Medicine chemistry Evaluation Studies as Topic Chemistry Clinical Reagent Indicators and Reagents Quantitative analysis (chemistry) |
| Popis: | We describe the construction, the reaction principle and the performance of Reflotron K+, a new Reflotron test for the quantitative determination of potassium in serum and heparinized plasma. The reaction principle is based on the introduction of the potassium cation via valinomycin into a non-polar phase; the accompanying loss of protons from the non-polar phase is detected by the colour change of a pH indicator. The multicentre evaluation of the reagent carrier system showed in median CVs of < 0.9% (within-series in heparinized plasmas) and 1.3% (run-to-run in control sera). The recovery in control sera was +/- 4% for seven laboratories. In the method comparison with flame emission spectrometry, using sera and heparinized plasma samples, regression analysis yielded correlations with slopes of 1.00 +/- 0.04 (median slope 1.005) and negligible intercepts. The reagent carrier system showed a linear response in the measuring range 2-12 mmol/l. Bilirubin (up to 513 mumol/l), triacylglycerols (up to 5,7 mmol/l), sodium (135-189 mmol/l) and ammonium ions (up to 590 mumol/l) did not interfere with the test. Comparison with the results from flame atomic emission spectrometry shows that the recoveries of Reflotron K+ and the direct potentiometric method are slightly and similarly influenced by total protein. With a panel of 28 drugs tested, no interference could be detected. Reflotron K+ provides a precise and reliable procedure for the measurement of potassium in serum and heparinized plasma. |
| Databáze: | OpenAIRE |
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