Pyroprobe

Pyrolyzer CDS Model Pyroprobe 2000 with coil sample probe and quartz boat sample holder Pyrolysis temperature about 650°C for 20 sec Pyrolysis sample size 0.2-0.3 mg GC Hewlett Packard Model 5890... 

Pyrrole main peak), alkyl pyrroles, benzeneacetonitrile, benzenepropanenitrile, indole in lower amounts than benzeneacetonitrile). Pyrolyser CDS Pyroprobe 5000 series (CDS Analytical Inc, Oxford, USA) pyrolyser interface 180°C transfer line 300°C valve oven 290°C [29, 30]. 

Pyrrole-2-carboxamide, diketodipyrrole, pyrrole 11,2-Chemical Data Systems, Oxford, USA) [27],... 

Figure 11.2 shows the pyrograms obtained from an aged linseed oil paint layer obtained with different pyrolysers in the presence of HMDS. Figure 11.2a was obtained with a continuous mode microfurnace pyrolysing injection system Pyrojector (SGE, Austin, Texas, USA) and Figure 11.2b with a CDS Pyroprobe 5000 series (CDS Analytical Inc., Oxford, USA). 

Pyrolysis-Gas Chromatography-Mass Spectrometry. In the experiments, about 2 mg of sample was pyrolyzed at 900°C in flowing helium using a Chemical Data System (CDS) Platinum Coil Pyrolysis Probe controlled by a CDS Model 122 Pyroprobe in normal mode. Products were separated on a 12 meter fused capillary column with a cross-linked poly (dimethylsilicone) stationary phase. The GC column was temperature programmed from -50 to 300°C. Individual compounds were identified with a Hewlett Packard (HP) Model 5995C low resolution quadruple GC/MS System. Data acquisition and reduction were performed on the HP 100 E-series computer running revision E RTE-6/VM software. 

The study of retained NMP in the films was conducted using a Du Pont DP-102 Mass Spectrometer. These films were heated in a tube-type pyrolysis furnace and the amount of NMP given off detected and quantitized against a calibration curve. Pyrolysis conditions were 750°Cx2 seconds with quantitation done on mass 99 molecular ion. A CDS-190 Pyroprobe was used for the pyrolysis study. 

Pyrolysis GC-MS Analysis. Flash pyrolysis was performed by using a pyroprobe 100 (Chemical Data Systems) temperature-control system. Samples were pyrolyzed from 150 to 750 °C with a temperature program of 20 °C/ms and a final hold for 20 s. After pyrolysis, the fragments were separated on a 25-m CP WAX 57 fused silica capillary column (temperature program 25-220 °C at 3 °C/min), followed by MS on a R 10-10 C (Ribermag, Rueil-Malmaison, France) operated at 70 eV and scanned from 20 to 400 m/z. 

Fig. 4.7.1. Temperature-time profile of a Pyroprobe instrument A ideal pyrolysis with the ribbon probe B coil probe with quartz boat and 200°C interface temperature. Explanation of terms Py-T pyrolysis temperature Py-t pyrolysis time T rise t temperature-rise time...

The most widely used system is the Pyroprobe (Chemical Data Systems, USA). The system is designed for varying the heating rate from 0.1 to 20 °C per ms... 

Fig. 4.7.4. Schematic diagram of Pyroprobe interface with coil probe connected to an GC injector ( on-line approach)...

The sample is secured inside the tube or boat which is carefully slid into the heating coil. The probe can be connected either directly to a horizontal GC injection port or first into the heated interface of the Pyroprobe system (see Fig. 4.7.4) that is connected with the GC injection port. The interface temperature is set typically between 200 and 250 °C. After sample insertion but before triggering the pyrolysis, a period of 5 to 10 s is required to eliminate oxygen from the system. 

The SI values can be used for comparing the pyrogram of an unknown sample and that of a known substance, and for determining the reproducibility of the pyrolysis system. Within the same laboratory, a similarity index of 95% for two consecutive Py-GC runs is possible using the Pyroprobe system. However, comparison of reproducibility as reported by different laboratories may not be justified, since individual groups have their own pyrolysis techniques. 

The MP-3 Thermal Chromatograph (Spex Industries, Inc., Me-tuchen, NJ) facilitates the slow (up to 40°C/min) controlled atmosphere pyrolysis of solid oil shale. The volatile compounds produced are monitored by both flame ionization and thermal conductivity detectors and after trapping, the whole or portions of the evolved organic proflle may be further subjected to GC and other analytical procedures. In contrast, the CDS 100 pyroprobe and associated CDS 820 reaction system (Chemi-... 

Font R, Mardlla A, Verdu E, Devesa J, Kinetics of the Pyrolysis of Almond Shells and Almond Shells Impregnated with CoClj in a Fluidised Bed Reactor and in a Pyroprobe 100, Ind. Eng. Chem. Res., 29(9), 1846(1990)... 

A CDS Pyroprobe 100 combined with a gas chromatograph (CP 9000) was used to pyrolyze and analyze a 70 mg sample. Pyrolysis temperature was set to 500 C. Heating rate was 600°C " and pyrolysis time was 10 s. A DB 1701 column (60 mxO.25 mm, 0.25 mm film thickness) was used for the separation of monomeric volatile compounds. Further details of the procedure can be found elsewhere [18]. External calibration was used for quantification of levogtucosenone. 

The reproducibility of the results for heated filament pyrolysers (CDS Pyroprobe 1000) and Curie point pyrolysers (Horizon Instruments) was reported for several samples [34]. This included several synthetic polymers, dammar resin, chitin, an insect cuticle, a hardwood (cherry), a seed coat (water lily), lycopod cuticle (fossil Eskdalia), as well as several organic geological samples. All samples were pyrolysed at 610° C for 5 s in a flow of helium. The residence time in the pyrolyser before pyrolysis was kept constant and the temperature of the sample housing was 250° C. Other parameters such as the temperature of the transfer line to the analytical instrument were also the same. Both systems were connected to a GC/MS system for the pyrolysates analysis. 

Figure 4.7.1. The variation in chromatographic peak heights for n-alkanes generated from torbanite pyrolysed by several techniques [35] A - laser micropyrolysis, B - sealed vessel microscale furnace pyrolysis, C - resistiveiy heated pyrolysis (HP 18580 A Pyroprobe), and D - microfurnace pyrolysis (SGE Pyrojector).

Pyroprobe 1000 from CDS) [20] is shown in Figures 18.4.1 and 18.4.2. Figure 18.4.1 shows the yield in several pyrolysis products obtained from almond shells at 850 C, and Figure 18.4.2 shows the same results for municipal solid waste. 

The pyrolysis of nucleic acids generally occurs between 200 and 250°C, using a normal direct inlet probe. In order to decrease the possible contamination of the mass spectrometer, different pyroprobes - or even flash... 

Pyrolysis in the Presence of TMAH. A wide set of Fulvic Acids (FA), Humic Acids (HA) and related materials from different origins have been thus far studied using the TMAH/thermochemolysis procedure (9,15-17,22,24,25). The TMAH procedure has mainly been performed in pyroprobe units, in much the same way as the conventional flash pyrolysis using either quartz tubes and/or a platinum coil, by mixing the humic materii with a few drops of the reagent prior to heating. 

A new analytical procedure, termed TMAH thermochemolysis, has been used to assess the structure characterization of HS from a variety of samples. Although this procedure has mainly been performed in pyroprobe units at pyrolysis temperatures, it can also be conducted at subpyrolysis temperatures in sealed glass tubes. Therefore, this procedure can be easily implemented in any laboratory having gas chromatographic capabilities, in contrast to other chemolytic or pyrol c procedures. This is a potentially valuable advantage, because it makes the technique readily available to most geochemical laboratories. 

We thank the Natural Environment Research Council for financial assistance and Dr, E, Levy for the loan of a ribbon (Pyroprobe) pyrolyser, We also thank Dr, P.M.R, Smith,... 

The yield of hydrocarbons upon pyrolysis of shale (YP) -gas plus liquid - was determined by heating a known quantity of raw shale (approximately 5-10 mg) in a helium stream to a temperature in excess of 600°C using a Chemical Data Systems (CDS) quartz tube pyroprobe. The hydrocarbons were measured with a... 

The evolution of hydrocarbon products from shale as the pyrolysis temperature increased was monitored with a flame ionization detector and a yield versus temperature profile produced. Initially, pyrolysis was done with the CDS pyroprobe, but major limitations were observed, mainly with ensuring prompt removal of products. Subsequently, an automated concentrator and high-temperature pyrolysis furnace produced by Envirochem, Inc. was employed. This system permitted use of larger (50-100 mg) samples and the helium sweep gas effectively removed pyrolysis products (pyrolysates). However, the pyroprobe system is still used to measure YP as it provides a rapid, consistent determination. 

The MP-3 multipurpose thermal analyzer is manufactured by the Spex Industries. It pyrolyzes sample at programmed rates from 4°/min-40°C/min up to 1000°C. It was modified by the addition of two laminar flow controllers (HGC 187 Analabs) which provide controlled atmospheres of up to four gaseous mixtures. The CDS 820 (Chemical Data Systems) consists of a Pyroprobe 100 capable of delivering to a polymer sample a maximum heating rate of 20,000°C/sec the CDS 820 provides a controlled atmosphere for the Pyroprobe. 

Procedures for Pyrolysis. In the pyrolysis-GC-mass spectrometry experiments, about 1 mg of polymer was weighed into a quartz tube which was inserted into the heating coil of the Pyroprobe. The latter fitted directly into the injection port of the Perkin-Elmer 990 GC. The GC was operated at a manifold temperature of 220°C, injector temperature of 210 °C, interface temperature of 255°C, He flow rate of 83 mL min"1, and FID detection. Samples were pyrolyzed at 600°, 650°, 700°, 750°, 800°, 850°, 900°, and 950°C at a heating rate of 20,000°C sec"1. All samples were held for 20 sec at the final temperatures. 

Another more elaborate pyrolysis—chromatography—apparatus was described by MacLaury and Schroll (146), which permitted heating rates from 5 C/m to 5000°C/S. It consisted of a Chemical Data Systems geological sample and analysis system and a gas chromatograph. This system is a self-contained bench-top instrument that provides a means of trapping volatiles from a DSC 100 Pyroprobe solids pyrolyzer. The Pyroprobe uses a platinum... 

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