Simultaneously detection of calcium and magnesium in various samples by calmagite and chemometrics data processing

•The RBF-PLS. PRM, EFA, MCR-ALS and RAFA were employed to detection Ca2 + and Mg2 +.•Calmagite was employed as chromomeric reagent.•The analytical performance of RBF-PLS model was compared with PRM model.•The recovery of the profiles of chemical species was performed using MCR-ALS.•RAFA was applied to calculation the stability constants of complexes.

The current study describes results of the application of radial basis function-partial least squares (RBF-PLS), partial robust M-regression (PRM), singular value decomposition (SVD), evolving factor analysis (EFA), multivariate curve resolution with alternating least squares (MCR-ALS) and rank annihilation factor analysis (RAFA) methods for the purposes of simultaneous determination of trace amounts calcium (Ca2 +) and magnesium (Mg2 +) and exploratory analysis based on their colored complexes formation with 1-(1-hydroxy-4-methyl-2-phenylazo)-2-naphthol-4-sulfonic acid (calmagite) as chromomeric reagent. The complex formation Ca2 + and Mg2 + with calmagite was investigated under pH 10.20. The performance of RBF-PLS model in detection of minerals was compared with PRM as a linear model. The pure concentration and spectral profiles were obtained using MCR-ALS. EFA and SVD were used to distinguish the number species. The stability constants of the complexes were derived using RAFA. Finally, RBF-PLS was utilized for simultaneous determination of minerals in pharmaceutical formulation and various vegetable samples.

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