Use of adsorptive stripping voltammetry at the glassy carbon electrode for the simultaneous determination of magnesium(II) and aluminium(III): Application to some industrial samples Original Research Article

A new method for the simultaneous determination of Al(III) and Mg(II) based on adsorptive stripping voltammetry with tetramethylammonium chloride (TMAC) is presented. Applying the Osteryoung square wave stripping voltammetric technique (OSWSV) at a glassy carbon electrode; optimal experimental conditions were 0.01 M potassium nitrate (pH 5.0) solution with 0.02 M TMAC, preconcentration potential of −0.8 V and frequency of 30 Hz. Calibration plots have been constructed at different accumulation times. The relative standard deviation (n=10) at a concentration level of 1×10−7 M is 1.11% for Al(III) and 2.21% for Mg(II). Detection limits as low as 0.05 nM of Al(III) and 0.4 nM of Mg(II) were achieved after 120 s accumulation time. Possible interferences by metal ions, which are of great significance in industrial matrices, have been investigated. The method has been validated by analyzing standard reference materials (US NIST, SRM 1880 and 1889). Standard deviations for Portland cement were between 0.030 and 0.049. The method was also applied to some sugar and superphosphate fertilizer samples giving satisfactory results.