Pyroprobe systems

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 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. 

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. 

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. 

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... 

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-... 

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. 

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 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. 

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... 

Though the detailed pros and cons of different types of pyrolysis apparatus are discussed elsewhere, we feel obUged to share our own experience, woiking for 6 years with the CDS Pyroprobe 120. This system is weU known and in wide use. It produces a highly predictable temperature time profile for the filament and provides a means of varying the heating rate linearly over the initial temperature rise period (ramp control). 

For this method 2.5 mg of polymer was placed in a quartz tube, which had been equilibrated for 5 minutes at 180 °C. The sample was then pyrolysed for 20 seconds at 700 C using a pyroprobe CDS 190 with a platinum coil. Gas chromatography was conducted using a flame ionisation or a GC-MS system. 

The system applied in the study mentioned above consisted of a CDS model 122 Pyroprobe with a ribbon filament as the heating surface (see Chapter 3 and Appendix 1). This pyrolyser heats by varying the resistance of the platinum element. Temperature rise times for flash pyrolysis are typically of the order of milliseconds. IR spectra were obtained with an FT-IR bench system equipped with a CDS pyrolysis/FT-IR interface. The data were collected at 8 cm" with a deuterated triglycine sulfate (DTGS) detector. The interface is cylindrical in shape with two potassium bromide windows for the IR beam to pass through. 

The pyrolyser. Chemical Data System Pyroprobe Model 100 are used as the pyrolyser. Quartz sample tubes, 30 mm long and 1 mm i.d. are placed in the platinum coil heating probe. Pyrolysis conditions are varied until the most reproducible pyrograms were obtained. The optimum operation conditions are interface temperature, 120°C ramp, 20°C interval, 20 s final temperature 600 C. The ramp indicates rise in temperature C/m. Interval indicates the period for which the final temperature is held. 

METHOD 107 - PYROLYSIS - GAS CHROMATOGRAPHY OF POLYMERS. PLATINUM RIBBON OR COIL PROCEDURES (CHEMICAL DATA SYSTEMS PYROPROBE 190). 

Pyrolysis apparatus. Chemical Data Systems Pyroprobe 190 or equivalent. 

The Chemical Data System, Pyroprobe 190 Platinum Ribbon Coil Pyrolyser. 

Infrared spectra of polymers are also obtained in a rapid screening mode by pulse pyrolysis-FTIR using solid samples (ca. 0.1-0.5 mg) that are placed "as is" into the Pyroprobe-Pyroscan-FTIR system for semi-quantitative, qualitative information. The vapor phase IR spectrum in Figure 3a is that from a pulse pyrolysis (750 C for 10 sec) of a 100 mg sample of solid poly(styrene). The thermal decomposition of poly(styrene) to its slyrene... 

Pyrolysis gas-liquid chromatography (pyrolysis-GLC) was also used to characterize the fiber samples. The pyrolyzer used was a Chemical Data Systems 190 Pyroprobe with a platinum coil pyrolyzer. One to two millimeters of the fiber samples were pyrolyzed in clean quartz pyrolysis tubes. The pyrolysis temperature was 770°C, applied for ten seconds. The column used was a 60 meter, wide-bore, Carbowax 20M capillary column with an inside diameter of 0.75 mm (Supelco Inc.). In order to accommodate the capillary column it was necessary to modify the Perkin-Elmer 3920B gas chromatograph which was used. This instrument was designed for two packed columns. Because of the very low carrier gas flow rate used with capillary columns, it was necessary to introduce a make-up gas at the detector end of the capillary column to provide sufficient carrier gas flow through the detector. The make-up gas system consisted of a stainless steel line running from one of the injector ports to the effluent end of the capillary column. To reduce the contact of the pyrolysates with metal surfaces the... 

Pyrolyzer Chemical Data Systems 190 Pyroprobe with coil pyrolyzer Pyrolysis Temperature 770°C for 10 sec Gas Chromatograph Perkin-Elmer 3920B... 

In 1977, a thermogravimetric analysis unit was successfully coupled with a mass spectrophotometer, TG-MS. More recently, a coupled programmed pyroprobe-mass spectrophotometry system, also utilising IR spectroscopy, was employed as a means of describing degradation sequences as a function of temperature. The appHcation of these tools as a means to define polymer stmcture and degradation products is described. 9 refs. 

Figure 1.11 Setup of pyrolysis-liquid-trapped system (1) pyroprobe, (2) pyroprobe interface, (3) helium carrier gas inlet, (4) latex sample, (5) output needle, and (6) liquid collection vial. Reprinted with permission from F.C-Y, Wang, B. Gerhart and C.G. Smith, Analytical Chemistry, 199S, 67, 20, 3681. 1995, American...

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