Experimental and computer modelling speciation studies of the effect of pH and phosphate on the precipitation of calcium and magnesium salts in urine
| Autor: | Ravinder Sodi, Norman B. Roberts, Lakshminarayan R. Ranganath, John R. Duffield, Simon M Darn |
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| Rok vydání: | 2006 |
| Předmět: |
Magnesium phosphate
chemistry.chemical_classification Calcium Phosphates Analyte Chromatography Magnesium Precipitation (chemistry) Biochemistry (medical) Clinical Biochemistry Inorganic chemistry Salt (chemistry) chemistry.chemical_element Magnesium Compounds General Medicine Urine Calcium Hydrogen-Ion Concentration Phosphate Phosphates chemistry.chemical_compound chemistry Humans Computer Simulation |
| Zdroj: | Clinical chemistry and laboratory medicine. 44(2) |
| ISSN: | 1434-6621 |
| Popis: | Background: pH and phosphate concentration are the major determinants of precipitation in urine of the salts of calcium and magnesium. This study aims to model the process of salt precipitation and establish whether the acidification of urine samples is necessary for the accurate measurement of calcium and magnesium in a clinical laboratory setting. Methods: Urine samples were collected from 21 patients, aliquots were taken from each patient sample and the pH was adjusted to cover the range 2.0-10.0. The analytical and biological variation for each analyte was established and used to calculate percentage changes and critical differences. The critical difference was used to assess whether there was a significant difference between acidified and un-acid-ified samples. The JESS (Joint Expert Speciation System) thermodynamic computer-modelling program was used to predict the distribution of salt species formed with varying pH values and phosphate levels in simulated urine. Results: The results showed that at a pH greater than 6.5, measured calcium, magnesium and phosphate significantly decreased as a result of precipitation (p |
| Databáze: | OpenAIRE |
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