THE THERMAL ANALYSIS OF URINARY CALCULI

DIFFERENTIAL THERMAL ANALYSIS AND THERMOGRAVIMETRY

Abstract

The thermal analysis has been widely used for the identification of materials, quantitative application and calorimetric measurements.
Recent advances introduced various methods to facilitate interpretation, and rapid analysis of microsamples. Differential thermal analysis (DTA) and thermogravimetry (TG) have been used most widely. DTA and TG of urinary calculi have been studied.
(1) The TG-DTA curves of the principal constituents of urinary calculi have been described.
(2) The principal constituents of urinary calculi were analysed by TG quantitatively.
(a) The principal constituents were identified by X-ray analysis beforehand.
(b) Ideal chemical compositions were calculated for each constituent meterial.
(c) Weight losses directly measured on TG curves may give the weight proportion of each constituent. By calibration of measured weight losses against calculated chemical components, the constituents of mixed calculi (about 58) were determined quantitatively. It is noticed that organic matters are found in amount of about 1.2-6.5% regardless the sizes of urinary calculi.
(3) Good reproducibility for practical purposes has been usually obtained in the case of urinary calculi composed of calcium oxalate and calcium phosphate.
(4) Thermal analysis with automatic recording and microanalyser systems are useful in the field of urology.