1984 Volume 34 Issue 5 Pages 584-589
The purpose of this study was to establish fundamental conditions, and to develop atomic absorption techniques for the determination of titanium fluoride compounds which are applied to human enamel for caries prevention.
A polarized Zeeman atomic absorption spectrophotometer (HITACHI 180-80) was used for the measurement of the absorbance of titanium (IV). The optimum conditions for titanium (IV) were as follows: hollow cathode lamp, wave length, 364.3 nm; lamp current, 12.5 mA; height of burner, 10.20 mm; flow-rate of acetylene, 0.37kg/cm2; and flow-rate of nitrous oxide, 1.60 kg/cm2.
Under these conditions, the absorbance showed a linear relationship to the concentration Ti (IV) within the range of 1.0-8.0 μg/ml. Of the ions and inorganic acids coexisting in human enamel sample solutions, calcium, phosphorous, magnesium, fluoride and some inorganic acids caused some interference in the absorbance. The interference of phosphorous could be suppressed by addition of lanthanium, but that of other ions could not be suppressed. With “standard addition” method for determination of Ti (IV) in enamel samples, good determination reproducility could not be obtained.
From these results, we suggest that the direct determination of Ti (IV) in human enamel is difficult and that pretreatment procedure to separate Ti (IV) from coexisting ions is required.
