Application of ATR FT-IR spectroscopy and chemometrics for the differentiation of brown shoe polish stains as forensic evidence Sharma Spriha1, Sharma Sweety2, Singh Rajinder3,* 1Assistant Professor, Department of Forensic Science, Chandigarh University, Mohali, India 2Assistant Professor, National Forensic Science University, Delhi Campus, India 3Professor, Department of Forensic Science, Punjabi University, Patiala, Punjab–147002, India *Corresponding Author: Dr. Rajinder Singh, Professor, Department of Forensic Science, Punjabi University, Patiala, Punjab-147002, India, E-mail: rajchandel7@gmail.com Contact : +91-8968741133
Online published on 19 December, 2023. Abstract Introduction Shoe polish stains can be encountered as trace evidence in criminal cases like physical/sexual assault, burglary, murder and theft. It can therefore, serve as crucial evidence to establish a link between the suspect, the victim, and the crime scene. Materials and method In the present study, total 17 brown shoe polish samples of different brands were collected and analysed using Attenuated Total Reflectance (ATR) Fourier Transform Infrared (FT-IR) spectroscopy in combination with chemometrics method that is PCA for the discrimination purpose. In addition, the effect of substrates is also studied to simulate the actual case conditions. Results The current approach delivered discrimination power up to 100% for the differentiation of different brands of brown shoe polish samples. Further, blind test was performed to validate the results by analysing six unknown samples which were classified and linked accurately with their respective source samples. Conclusion The developed methodology demonstrates a great potential of ATR FT-IR to analyse evidence in a rapid, novel and non-destructive manner. Top Keywords ATR FT-IR, Spectroscopy, Chemometrics, Shoe Polish. Top |