Low level detection and quantification of carbonate species using thermogravimetric and differential thermal analysis

This report describes a procedural manual for the newly acquired simultaneous thermogravimetric and differential thermal analysis system and details of initial testing to determine the low level detection and quantification of carbonate species. This work was carried out as part of the Science Facilities’ Maintenance and Development of Capability (MaDCap) project. The report firstly introduces the techniques of thermal analysis and BGS’s capabilities in this area. The report then details a series of experiments designed to determine the low level detection and quantification of carbonate species (calcite, dolomite and siderite). Results indicate that combined TGA-DTA analysis offers significantly lower levels of detection than other mineralogical techniques such as X-ray diffraction analysis. Measured carbonate species concentration levels as low as 200 ppm (dolomite and siderite) and 150 ppm (calcite) in synthetic mixtures are proved. Lower detection limits are possible but proving these is precluded by the difficulty of handling/weighing such small quantities.