Department of Forensic Science, Punjabi University Patiala, Punjab, India.
J Forensic Sci. 2021 Mar;66(2):594-607. doi: 10.1111/1556-4029.14609. Epub 2020 Nov 2.
Vermilion (sindoor) is considered sacred in the Hindu religion, and it is used routinely throughout the world by married Hindu women along the line of hair parting during marriage ceremonies, religious rituals, and festivals. Owing to its esthetic appeal, it is sometimes illegally used as a food additive; leading to potential health risks. Therefore, due to the aforementioned reasons, vermilion can likely be encountered as trace evidentiary material during crime investigations, particularly in cases of sexual and physical offenses against women. Analysis of such evidence can provide a link between the criminal, the victim, and the crime scene and thereby be utilized as associative evidence in the court of law. In the present study, ATR-FTIR spectroscopy has been used for the examination of 37 different manufacturers of vermilion. Chemometric methods such as principal component analysis (PCA) and PCA-LDA were performed on the obtained spectra for objective interpretation of results. PCA delivered 99.06% discrimination of samples while PCA-LDA employed for classification purpose delivered 95.25% calibration accuracy and 88% validation accuracy. Afterward, the validity of the chemometric methods employed was tested by blind testing of samples. A preliminary study on the effect of selected substrates (cotton cloth, tissue paper, glass, and plastic) on sample analysis indicates that while sample stain on substrates could be linked to its parent source even after a month, linking an aged samples (after 8 months) could be hindered due to evaporation of components present in vermilion. Overall, the current methodology utilized has a potential prospect in future forensic-casework.
朱砂（红色颜料）在印度教中被视为神圣之物，全世界已婚的印度教妇女在婚礼仪式、宗教仪式和节日期间都会沿着头发分界线常规地使用它。由于其美学吸引力，它有时会被非法用作食品添加剂，从而带来潜在的健康风险。因此，由于上述原因，在犯罪调查中，尤其是在针对妇女的性犯罪和身体犯罪案件中，朱砂很可能作为微量证据材料被发现。对这种证据的分析可以在犯罪者、受害者和犯罪现场之间建立联系，并因此在法庭上被用作关联证据。在本研究中，我们使用衰减全反射傅里叶变换红外光谱法（ATR-FTIR spectroscopy）对 37 种不同制造商的朱砂进行了检查。对获得的光谱进行了主成分分析（PCA）和主成分判别分析（PCA-LDA）等化学计量学方法的分析，以便对结果进行客观解释。PCA 可实现 99.06%的样品区分度，而用于分类目的的 PCA-LDA 可实现 95.25%的校准准确率和 88%的验证准确率。之后，通过对未知样本的盲样测试来检验所采用的化学计量学方法的有效性。对选定基底（棉布、纸巾、玻璃和塑料）对样品分析影响的初步研究表明，即使在一个月后，基底上的样品污渍仍可与其母体来源相联系，但由于朱砂中存在的成分蒸发，对 8 个月后的陈旧样本进行联系可能会受到阻碍。总体而言，当前所采用的方法在未来的法医工作中有很大的应用前景。
