Four toothpaste brands were analyzed for their fluoride and chloride contents (Sensodyne, Colgate, Close-Up and Hapee). Standards were run in the ion chromatograph, and the retention times and the concentration-peak area relationships of each were drawn from the data. Out of which only Sensodyne and Hapee showed quantifiable amounts of chloride in the toothpaste formulation. Calculation yielded concentrations of 0.00923% and 0.016% chloride in both toothpastes, respectively. Other samples had no sufficiently quantifiable amounts of both anions, suspected to be consequence of matrix effect.
Use other MP: carbonate/bicarbonate buffer, KOH Use gradient elution Standard addition instead of calibration curve Homogenization of samples Analyze other anions (MFP, benzoate, sulfate, phosphate) Method validation
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