Elemental studies and mapping of cholesterol and pigment gallstones using scanning electron microscopy–energy dispersive spectroscopy

Abstract

Gallstone formation is one of the most severe human diseases, with regional differences in gallstone composition worldwide. The formation of gallstones inside the gallbladder is a complex process and is still under debate despite advances in instrumentation. This study was an in‐depth analysis of the chemical, structural, and elemental composition of cholesterol and pigment‐type gallstones using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy–energy dispersive X‐ray spectroscopy (SEM–EDS). Thermal gravimetric and differential scanning calorimetry (TG‐DSC) analysis was also carried out on gallstones to predict their thermal behavior. FTIR spectroscopy was employed to distinguish the cholesterol and pigment gallstones. Using SEM, we performed the morphological studies of gallstone and EDS were carried out to analyze elemental distribution within the gallstones. Elemental imaging and mapping of the major and minor elements within the cholesterol and black pigment gallstones were carried out, revealing the stone's heterogeneous nature. The level of heavy and toxic elements was found to be higher in pigment stones than in cholesterol gallstones. The results obtained from TG‐DSC are well correlated and supported by the results from FTIR spectroscopy.