Estimation of the essential inorganic constituents of commercial toothpastes

Abstract

Commercial toothpastes, randomly sampled from the open market were analyzed for fluoride, phosphate, calcium, sodium, potassium, magnesium, moisture content and pH. Colorimetry was used to determine the levels of fluoride using the SPADNS-zirconyl chloride method and phosphate using the phosphovanadomolybdate method. Atomic Absorption Spectrometer<b style=""> </b>was used to determine the levels of calcium and magnesium, while Flame Photometry was used for sodium and potassium determination. Moisture content was 20-39%, with 85% of the samples having water levels > 29 wt %. The pH of the toothpastes ranged from 4-8, with 60% of them having a neutral pH. The levels of constituents depend on the method of solubilization of toothpaste, with concentrated nitric acid digestion giving the best results. The concentrations were: fluoride, 1.0-1.55; phosphate, 3-20; calcium, 0.04-1.26; sodium, 12-38; potassium, 0.01-0.99; and magnesium, 0.1-2.3 mg/g. The health implications for tooth care and of assimilation of the elements during the mouth cleansing process, especially when present at unacceptable levels, was discussed.