Pyrolysis Py

Py-GC is mainly employed in structure analysis that includes the exploration of monomer arrangement in the (co)polymer system, such as the number-average sequence length and 

Pyrolysis is carried out either outside or inside the identification instrument. In the outside mode, the thermal degradation is carried out by a pyroprobe connected to the injection port of a GC using a selected technique - time-programmed or flash pyrolysis. GC-separated individual pyrolysates can be identified with different equipment connected to the GC, e.g., Py-GC-MS, Py-GC-FTIR or Py-GC-AED (atomic emission detector). Advances in Py-GC and the different configurations can be summarised as follows  

Direct pyrolysis-mass spectrometry (Py-MS) is applied to determine the primary structure of macromolecules and to investigate selective thermal degradation mechanisms. This technique allows the thermal decomposition products of the polymer sample to be observed directly in the ion source of the mass spectrometer, so that the evolving products are ionised and continuously detected by repetitive mass scans almost simultaneously with their formation 805917 757742. Since pyrolysis is accomplished under high vacuum, the thermal fragments are readily removed from the hot zone, and because of the low probability of molecular collisions and fast detection the occurrence of secondary reactions 

In recent years pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) has been widely used for the separation and identification of the volatile pyrolysis products of polymers and can be considered as the most convenient method to detect simultaneously the presence of decomposition products qualitatively and quantitatively 589987. Evolved gas analysis (EGA) performed by using a GC coupled with a mass-selective detector offers a number of advantages for the decomposition study. The number of peaks seen in the total 

Recently, an in-line pyrolysis unit for the MS study of the thermal stability of light oils or volatile liquid prepolymers has been presented [a.l3]. A sealed glass ampoule is dropped into the furnace, which is preheated and controlled at the desired temperature. After the chosen pyrolysis time has elapsed, a piston is screwed down to break the ampoule, and the pyrolysis products are thereby released and impelled by helium carrier gas via a heated capillary into the mass spectrometric source - for GC-MS analysis the products pass directly through the GC column before entering the MS source. This new pyrolysis unit has small dead volume, is precisely temperature-controlled and contains no cold regions where products would condense. 

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Diffusive sampler Membrane extraction (MESI) Liquid-liquid extraction (LLE) Solid-phase extraction (SPE) SPE-PTV-GC Solid-phase microextraction (SPME) Headspace GC (SHS, DHS) Large-volume injection (LVI) Coupled HPLC-GC Membrane extraction (MESI) Difficult matrix introduction (DMI) Conventional solvent extraction methods 1 Pressurised solvent extraction methods Headspace GC (SHS, DHS) Thermal desorption (TD, DTD) Pyrolysis (Py) Photolysis Photon extraction (LD) Difficult matrix introduction (DMI)... 

In addition to GC/MS, high performance liquid chromatography (HPLC/MS) has been used to analyse natural resins in ancient samples, particularly for paint varnishes containing mastic and dammar resins [34]. A partial limitation of chromatographic techniques is that they do not permit the analysis of the polymeric fraction or insoluble fraction that may be present in the native resins or formed in the course of ageing. Techniques based on the direct introduction of the sample in the mass spectrometer such as direct temperature resolved mass spectrometry (DTMS), direct exposure mass spectrometry (DE-MS) and direct inlet mass spectrometry (DI-MS), and on analytical pyrolysis (Py-GC/MS), have been employed as complementary techniques to obtain preliminary information on the... 

Biomaterials. Recently, an improved experimental setup for time-resolved insource pyrolysis /py./ field ionization /f.i./ mass spectrometry /m.s./ has been described (10) and examples of its application to studying various biomaterials have been shown. There is a number of characteristic features of the py.-f.i.m.s. that are... 

A detailed study was devoted to amber forgeries. It was shown by the authors that analytical pyrolysis (Py-GC, PYGC/MS) can provide undeniable proof that materials under investigation are amber forgeries and also quite precisely characterize the nature of these substitutes. Early Bakelites, modem phenolic resins, polystyrene, epoxy resins, and a wide range of unsaturated polyesters were identified as the most often used materials. 

A typical pyrogram obtained by pyrolysis (Py)-GC/MS of wood samples at 550°C is presented in Fig. 2. Peak assignments are presented in Table 1. The compounds identified by Py-GC/MS have been classified as carbohydrate-derived (C)... 

Pyrolysis (Py) involves the thermal degradation of organic matter in an oxygen-free environment. There are many apphcations of analytical pyrolysis, and a large number of them are focused on polymers. From the fingerprints of the pyrolysis products of such macromolecules, valuable information can be obtained about the initial samples. Nowadays pyrolysis in combination with GC/MS is... 

Dieckow, J. Mileniczuk, J. Gonzalez-Vila, F.J. Knicker, H. Bayer, C. No-tiU cropping systems and N fertilisation influences on organic matter composition of physical fractions of a subtropical Acrisol as assessed by analytical pyrolysis (Py-GC/MS). Geoderma 2006,135, 260-268. 

Pyrolysis (Py) method Curie point Fnmace Cnrie point Direct probe... 

The following protocol describes a procedure for rapid characterization of synthetic polymers by heated filament and laser pyrolysis py-(GC-MS) [16]. 

Pyrolysis (Py), demineralization (DM), oxidation (Ox) (1-peroxyacetic acid), reductive and nonreductive alkylation (R), chemical (SiCl4-NaI), nitrogenation (N)(l ammoxidation, 2-urea). 

However, the applicability of GC (GC/MS) combined with pyrolysis, Py-GC (Py-GC/MS) ranges the entire area of the organic substances if they could yield fragment by thermal energy or chemically assisted thermolysis. Thus, the modem Py-GC (Py-GC/ MS) is on the new horizon for the polymer characterization including intractable materials by conventional methodologies. 

Figures 2.1 and 2.2 illustrate the schematic flow diagrams of the measuring systems of the pyrolysis (Py)-GC/MS and evolved gas analysis (EGA)—MS, respectively. In both systems, the vertical micro-furnace pyrolyzer (Frontier Lab., PY-2020iD) mounted on...

The incorporation of a gas chromatography (GC) stage between pyrolysis (Py) and mass spectrometry (MS) has the obvious advantage of refining the detail that can be achieved in structural analysis and rendering MS identification of pyrolysis prodncts more certain. The application of Py-GC-MS to the identification of complex mixtnres of volatile compounds produced under high temperature conditions has been reviewed by Chang and Tackett [1]. 

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