Characterization of kidney stones using thermogravimetric analysis with electron dispersive spectroscopy.

Urinary calculi are formed from a result of biological mal-adjustment of urine leading to deposits of salt and mineral crystals along the urinary collecting system. They are usually multiphasic material with complex compositions. The objective of this study is to identify and characterize a series of urinary calculi samples using a combination of thermogravimetric analysis (TGA) with electron dispersive spectroscopy (EDS). These samples were retrieved during percutaneous nephrolithotripsy. Additional characterization by hardness value and microstructure is also carried out for co-relation study. The samples are found to be uric acid, calcium oxalates and magnesium ammonium phosphate hexahydrate. TGA is indeed one of the viable analytical tools for urinary calculi as it is fast and simple. The combinational application of EDS is beneficial when there is a need for differentiated qualitative chemical composition detection at the identified nuclei position for urinary calculi with spatial variation in composition. The combination of TGA and EDS will thus facilitate the correct diagnosis and treatment by clinicians.