Institute of Forensic Science & Criminology, Panjab University, Chandigarh 160014, India.
Central Forensic Science Laboratory, CBI, New Delhi 110003, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2021 Nov 5;260:119982. doi: 10.1016/j.saa.2021.119982. Epub 2021 May 20.
Thermal papers are replacing the conventional form of printing and are being extensively used across the globe. This study encompasses a non-destructive approach to examine thermal papers by using ATR-FTIR spectroscopy and Video Spectral Comparator (VSC), where the former technique helps in characterizing and discriminating different samples and the latter helps in deciphering the faded prints on thermal paper. The qualitative analysis of the spectroscopic data based on peak to peak comparison and quantitative analysis using chemometrics has been done to obtain high discriminating power. Multivariate analysis using HCA gave a discriminating power of 83.82% and PCA showed a variance of 95.64%. The strength of the study is portrayed through the decipherment of artificially and naturally faded thermal papers using VSC and analyzing the effect of different storing conditions on their rate of fading.
热敏纸正在取代传统的打印形式，在全球范围内得到了广泛的应用。本研究采用衰减全反射傅里叶变换红外光谱（ATR-FTIR）和视频光谱比较仪（VSC）对热敏纸进行了非破坏性检测，前者有助于对不同的样本进行特征分析和区分，后者有助于对热敏纸上已褪色的打印件进行解读。通过峰对峰比较进行光谱数据的定性分析，并使用化学计量学进行定量分析，以获得较高的鉴别能力。使用 HCA 进行多元分析得到了 83.82%的鉴别能力，PCA 显示方差为 95.64%。本研究的优势在于通过 VSC 对人为和自然褪色的热敏纸进行解读，并分析不同储存条件对其褪色速度的影响。
