Spectrophotometric determination of significant minerals in milk samples found in Lahore (Pakistan) for ensuring food safety

This work was carried out for determination of essential and toxic metals ions in different milk powder samples commonly found in Lahore (Pakistan). Samples were collected from local markets and after dry ashing, they were dissolved in 2M nitric acid for complete mineralization. Then the concentration of metal ions was determined by flame photometry and atomic absorption spectrometry. The concentration levels of cadmium, lead and nickel were found to be below detection limits in all samples, whereas the maximum values of sodium, potassium, calcium, magnesium, iron, and zinc were 48.55, 0.96, 4.94 mg/g, and 768, 4.12 and 3.02 μg/g respectively. Minimum amounts of these metal ions were: 3.69, 0.07, 0.85 mg/g and 214, 0.21, 1.02 μg/g, respectively. The amounts of all metal ions were found to be within safe limits as recommended by WHO.