Advances and Applications of FTIR Spectroscopy: Precision, Accuracy, and Validation Challenges

Abstract

Fourier Transform Infrared (FTIR) spectroscopy is a widely used analytical technique known for its precision, accuracy, and cost-effectiveness. This review evaluates the advancements in FTIR and portable FTIR spectroscopy, focusing on their validation, comparative performance, and challenges in various applications, including pharmaceuticals, forensics, environmental monitoring, and biomedical diagnostics. Comparative analysis indicates that benchtop FTIR systems offer superior spectral resolution and sensitivity, whereas portable FTIR provides real-time, on-site analysis with minimal sample preparation. Studies have demonstrated that FTIR achieves high accuracy in pharmaceutical quality control (R² > 0.999), forensic hematoma analysis (R² = 0.88), and food authentication (R² = 0.96). Portable FTIR has shown comparable detection efficiency in environmental pollution monitoring and on-site pharmaceutical cleaning validation. However, challenges such as spectral interferences, regulatory validation, and variations in sample composition impact precision and reliability. The application of chemometric techniques including PCA and PLS-DA for spectral analysis has enhanced classification results and recently developed AI-driven methods show potential for future advancements in this field. Standardization processes together with regulatory harmonization efforts need to develop to expand the applications of FTIR. This review demonstrates FTIR's continued importance in analytical science by solving existing challenges to implement this technique.