Introduction: Non-destructive analysis of biological evidence has been paramount importance in the forensic inves- tigation since it is an effective tool in establishing a standard that could be employed to differentiate ensuing destruc- tive tests of bio-fluids upon sample division between the plaintiff and defendant. Species identification of bloodstain found at the crime scene is very crucial in routine forensic work as this can assist the initial investigation by incor- porating or excluding stain that is not human and to identify its origin if animal blood is involved. Methods: In this research, identification and discrimination of various blood species collected from seven domestic animals namely chicken, cow, deer, duck, fish, goat, and pig were investigated using non-destructive analytical techniques; ATR- FTIR and visible spectroscopy coupled with principal component analysis and linear discriminant analysis (PCA- LDA) for classification purposes. Results: ATR-FTIR FTIR spectroscopic study demonstrated a higher rate of successful classification ( 90%) as compared to visible spectroscopic technique. Conclusion: ATR-FTIR spectroscopy has been an ideal, robust, and suitable tool for determining the blood species of domestic animals. The predictive model from PCA-LDA analysis can be utilised to produce higher classification rate for species determination from blood traces.
An optical fiber chemical sensor for the determination of free glutamate in food samples was fabricated based on the
immobilization of 0.1 M copper(II) nitrate trihydrate onto sol-gel glass powder which was then mixed with methyl cellulose
to form a pellet. A distinctive colour change from light blue to dark blue was observed in the presence of glutamate in
less than 1 min. The colour change was measured by reflectance spectrophotometer at 691 nm. A linear relationship
between the reflectance intensity and glutamate concentration was observed in the range of 12.5 to 500 mM with a limit
of detection of 10.6 mM. This method is also reproducible with a relative standard deviation of less than 5%, no effect on
pH of the glutamate solution and a good recovery of above 80%. The sensor was used for the determination of glutamate
in common food items such as soups and flavor enhancers. The results obtained from the fabricated sensor were found
to be comparable with HPLC method.