Determination of Trace Heavy Metals in Human Teeth by Inductively Coupled Plasma Optical Emission Spectrometry After Preconcentration With Immobilized Nanometer Titanium Dioxide

A new method has been developed for the determination of trace amounts of heavy metals (Cd, Cr, Cu, Mn, Ni, and Pb) in human teeth based on the preconcentration with nanometer TiO2 immobilized on silica gel (immobilized nanometer TiO2) and determination by inductively coupled plasma optical emission spectrometry (ICP-OES). The effect of experimental parameters for the preconcentration of heavy metal ions, such as pH of the sample solution, its flow rate and volume, the type and concentration of eluent and interfering ions, have been investigated. Under optimal conditions, the detection limits of this method for the determination of heavy metal ions was between 18 and 57 ng L-1 The relative standard deviations (RSDs) for the determination of the analytes at the 10-ng mL(-1) level were found to be less than 6% when processing 50-mL amounts of sample solution. Verification of the accuracy of the method was carried out by the analysis of a standard reference material (NIST 1486 Bone Meal). The method was successfully applied to the determination of trace amounts of heavy metals in human teeth samples resulting in satisfactory results.