Determination of titanium dioxide added as an inert marker in chicken digestibility studies

A method was developed to determine the concentration of titanium dioxide in poultry digesta samples, obtained from the lower half of the small intestine of three-week-old male broiler chickens. Titanium dioxide was added at a rate of 5 g kg−1 as a dietary marker. .1 g of freeze-dried digesta sample was required. The sample was ashed and dissolved in 7.4 M sulphuric acid. Hydrogen peroxide (30% vol.) was subsequently added, resulting in the typical orange colour the intensity of which was dependent upon the titanium concentration. Aliquots of the solutions obtained and of similarly prepared standard solutions were analysed using a UV spectrophotometer and measuring the absorbance at 410 nm. tion of the method showed that: 1. pared samples could be kept for at least 48 h before measuring on the spectrophotometer. anium dioxide recovery was not significantly affected by ashing or filtering of the sample during preparation. er components in the digesta sample did not affect absorbance. urate and reproducible results were obtained when using the chicken digesta samples. concluded that the method was suitable in the quantitative determination of titanium dioxide concentration in chicken digesta samples obtained during digestibility studies.