Determination of heavy metals in toothpastes containing tin as an active ingredient

Abstract

This study discusses the technical rationale behind the development and validation of an alternative AAS and colorimetric methods for the determination of heavy metals in toothpastes containing tin as an active ingredient. Using BIS 6356:2001 method, it is found to be difficult to analyze toothpastes containing <100 ppm Pb, based on the PbS color formed by addition of sodium sulfide. In the present investigation an alternative, highly sensitive and specific AAS method has been developed and validated. The minimum detection limits are found to be 0.222 µg/mL, 0.010 µg/mL, 1.873 ng/mL, 5.465 ng/mL, 2.949 µg/mL for Pb, Cd, Hg, As and Sn respectively.