Fourier transform infrared spectroscopy in the analysis of biominerals and urolithiasis across species: from molecular signatures to clinical interpretation

Urolithiasis is a common manifestation of pathological biomineralization in human and veterinary medicine. Reliable identification of urinary calculi composition is essential for understanding stone formation, guiding therapy, and preventing recurrence. Fourier transform infrared spectroscopy is widely used for routine urolith analysis because of its molecular specificity, speed, and minimal sample preparation. This review summarizes the principles and application of infrared spectroscopy in the analysis of urinary biominerals, with emphasis on comparative aspects of urolithiasis across species. Major measurement approaches and their suitability for heterogeneous biological samples are briefly discussed. Key spectral regions enabling identification of calcium oxalates, calcium phosphates, struvite, urates, cystine, and carbonate minerals are outlined. Comparative data from human and animal studies show that despite species dependent differences in stone prevalence, the fundamental vibrational features of urinary biominerals remain conserved. The review highlights the value of infrared spectroscopy as a robust analytical tool supporting unified interpretation of urolith composition and biomineralization mechanisms across species.