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Updated: Jun 28, 2026

Clean Sampling and Analysis of River and Estuarine Waters for Trace Metal Studies
Published on: July 1, 2016
A chemometric study of the simultaneous determination of calcium and magnesium in natural waters
F Blasco Gómez1, F Bosch Reig, P Campíns Falcó
1Departament de Quimica Analitica, Facultad de Quimica, Universidad de Valencia, C/ Doctor Moliner 50. Burjassot, Valencia, E-46100, Spain.
Abstract:
A method for the simultaneous spectrophotometric determination of calcium and magnesium in mineral waters with an FIA system is tested. The method is based on the reaction between the analytes and arsenazo(III) at pH 8.5. The calculations of the amounts of both analytes in the samples are carried out with the H-point standard addition method (HPSAM) for ternary mixtures, and with a partial least squares (PLS) model after a proper variable selection. The results obtained for the determination of calcium were comparable using both methods. The employment of the HPSAM brings to our attention the influence of the calcium concentration in the sample to the development of the reaction between magnesium and arsenazo(III). HPSAM also permits to estimate the concentration of magnesium in the samples.
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