Authors:A. Pappa, S. Kyriakou, K. Mikedi, N. Tzamtzis, and M. Statheropoulos
The design, the abilities and a characteristic application of an in-house made interface for combining thermogravimetry (TG)
with mass spectrometry (MS) are presented. The TG-MS interface consists mainly of three co-axial tubes. The position of the
intermediate tube was determined after calculation of the temperature profile at the TG furnace exit tube. The inner tube
position was determined taking into consideration its protection against condensation of heavy molecules and the time delay
for the transfer of the evolved gases. This interface allows either continuous sampling and transferring of the evolved gases
from the TG to the MS or repetitive introduction of short sampling pulses of TG evolved gases to MS. The interface is capable
of coupling various commercial instruments. In the present work two configurations of this interface are demonstrated. Finally
an example of application of this interface on forest fuel pyrolysis is presented.
Authors:J. May, A. Del Grosso, R. Wheeler, and N. Etz
A TA Instruments Thermal Analysis System (TG) has been interfaced to the Hewlett Packard 5972 quadrupole mass spectrometer.
An OSS-2 variable outlet splitter was plumbed between the TG and the mass spectrometer. This interface allows continuous monitoring
of the ion intensities of mass peaksm/e=18 (water) andm/e=44 (carbon dioxide) used to elucidate the TG transitions attributable to residual moisture in freeze-dried biological products.
Moisture specifications must be met in order to insure product stability throughout the approved shelf life. TG/MS results
are discussed for BCG Vaccine, BCG Live (Intravesical) and U. S. Standard Antihemophilic Factor. Karl Fischer and TG/MS moisture
results are compared.