SLURRY PROCEDURE FOR THE DETERMINATION OF TITANIUM IN PLANT MATERIALS USING ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRY

The use of slurries to determine the titanium content of vegetables by electrothermal atomic absorption spectrometry is discussed. As slurries from ground plant material produce serious deterioration in the pyrolytic graphite coating of the tube, the samples are first submitted to a process of mild calcination. Suspensions are prepared in the 0.1-10% range in water containing 0.03% hexametaphosphate. Calibration can be performed with aqueous standards although the standard additions method is recommended. The detection limit for titanium using 5% suspensions is 0.03-mu-g g-1 and the relative standard deviation is +/- 4.6% for 1.3 ng of the element introduced into the furnace. Data for the titanium content of lettuce, spinach, pea and commercially available paprika samples are in good agreement with those obtained by an acid dissolution procedure.