Evian Water sample : Magnesium =12 mg/L, Calcium = 38 mg/L I got : Magnesium =9 mg/L, Calcium = 29 mg/L Compare your results for the water samples provided with the quoted manufacturer concentrations. Provide an explanation as to the suitability of your method development for the analysis of calcium and magnesium in the mineral water supplied, together with possible reason(s) for any discrepancy in the two results.