Mass spectrometry with thermogravimetric analysis

Major instrumentation involved with the generation of thermal property behavior of materials includes thermogravimetric analysis (TG, TGA), DSC, differential thermal analysis (DTA), torsional braid analysis (TBA), thermomechanical analysis (TMA), thermogravimetric-mass spectrometry (TG-MS) analysis, and pyrolysis gas chromatography (PGQ. Most of these analysis techniques measure the polymer response as a function of time, atmosphere, and temperature. 

Degradation and complete removal of the organic component of bone is accompanied by mass loss of about 20-29% [9, 28-30, 32], emission of carbon dioxide (identified by mass spectrometry coupled with thermogravimetric analysis [7, 31]), and the release of water, associated in some studies to the bone organic phase decomposition [7] or loss of water from the hydroxyapatite crystal structure [30, 43]. Mass loss varies depending on the place of sampling [19,43], tissue type (cortical or cancellous) [30] or tissue health state [31,43]. 

Thermogravimetric analysis has also been used in conjunction with other techniques, such as differential thermal analysis (DTA), gas chromatography, and mass spectrometry, for the study and characterisation of complex materials such as clays, soils and polymers.35... 

High performance liquid chromatography (HPLC) and with mass spectrometry (LC-MS) Plasma emission spectroscopy (PES) Scanning electron microscopy (SEM) with elemental X-ray analysis Thermogravimetric analysis (TGA)... 

Thermogravimetric methods such as pyrolysis gas chromatography-mass spectrometry have been used to characterize hydrocarbon sludges from polluted soils [10]. In combination with conventional extraction and supercritical fluid extraction followed by gas chromatography-mass spectrometry, over 100 constituents were identified in soil samples. Thermogravimetric analysis-mass spectrometric results distinguished between the release of a component by thermosorption and by pyrolysis. 

Early devices fbr thermogravimetric analysis were limited in precision and convenience when compared with DTA or DSC equipment. Now devices for simultaneous DSC and TG are on the market which can operate at high temps in reactive atms permitting the simulation of high temp reactions on a micro scale. The use of TG for the study of reaction kinetics was described in Sect 5.3.3. An exptl study of the sublimation of ammonium perchlorate was published by Jacobs and Jones (Ref 25). Similar techniques should find application in the study of other propint systems. The product gases have been collected for further analysis using gas chromatography and mass spectrometry... 

FIGURE 8.14 Thermogravimetric analysis of sodium alginate under helium atmosphere coupled with mass spectrometry analysis of the evolved gases. Heating rate 10°Cmin 1. (Adapted from Raymundo-Pinero, E., et al., Adv. Mater., 18, 1877, 2006.)... 

Thermogravimetric analysis (tga) and thermal desorption/mass spectrometry (td/ms) were used as described previously [5]. Sample sizes were typically 10 mg, with heating rates of 10°C/min. 

Dyszel (1985) performed a thermogravimetric analysis/atmospheric-pressure chemical-ionization mass spectrometry (TGA/APCIMS) on green coffee beans. Using various combinations of 14 (M+1) ions, the author concluded that unknown coffees can be matched, with varying degrees of certainty, to known coffees for their country of origin. 

The gases evolved during thermogravimetric analysis may be analyzed by mass spectrometry. A typical installation consists of a quadrupole mass spectrometer, fitted with an enclosed ion source, and sampling the effluent from a thermal analyzer via a heated capillary inlet with by-pass. 

BH2 NH2-)n oligomers with n>5 have been studied by thermogravimetric analysis (TG) and differential scanning calorimetry (DSC) [30], as well as by mass spectrometry and X-ray photoelectron spectrometry. The results have been interpreted in terms of a large cyclic structure of poly(aminoborane) [31]. 

The LaxM(fsa)2cn,N03.H20 complexes (M = Ni, Cu) and some of their pyrolysis products were characterized by Elemental Analysis (Laboratoire Central d Analyse, C.N.R.S., Vernaison, France) in order to control their stoichiometry. Thermal treatments of the complexes and of Mont/LaxM(fsa)2en,H20 were carried out in a ThermoGravimetric Analysis (T.G.A.) apparatus coupled with a Balzers QMG 420 C mass spectrometer, under 02/Ar (1/1, 15 ml/min) atmosphere with a 100°C/h temperature ramp. KBr pellets (0.5% dispersion in O.lg KBr) were analyzed by Infra-Red spectrometry (Nicolet 710 FT-IR spectrometer). X-Ray diffractograms of powdered solids spread on a glass plate were recorded on a Siemens D500 diffractometer (Cu Ka radiation, X = 1.54056 A) in the reflection mode. ... 

A two-step degradation mechanism for pofycaprolactone has been proposed by Persenaire et al. [42], They studied thermal degradation of PCL by high resolution thermogravimetric analysis (TGA) simultaneously coupled with mass spectrometry (MS) arrd Forrrier transform infrared spectrometry (FTIR). Based on evolved gas analysis by both MS and FTIR it was concluded that the first step was a random rupture of polyester chains via cw-elimination reaction which produced H2O, CO2, and 5-hexanoic acid. The second step is an unzipping depolymerization process at the chain ends with hydroxyl end groups to form e-caprolactone (see Fig. 4.2). 

Thermogravimetric analysis (Chapter 2), for example, has been used in studies of polymer degradation, activation energy, phase transitions, and also for the effect of antioxidants on polymer ageing and polymer lifetime studies. Coupling this technique with mass spectrometry (Chapter 3) enables further information to be obtained on the nature of polymer decomposition products, which accompany polymer weight changes. 

Thermogravimetric analysis coupled with gas chromatography and mass spectrometry has been used to study the nature of the volatiles produced during the curing of epoxy resins. ... 

Thermogravimetric analysis has also been coupled with gas chromatography /mass spectrometry and with gas chromatography to obtain information on styrene-isoprene block copolymers. 

---