Temperature programmer

The TDU equipment (commercially available from Gerstel GmbH, Miilheim an der Ruhr, Germany) is fully automated and connected on-line to a GC equipped with a programmable temperature vaporizer (PTV) injector for simultaneous cryotrapping of the analytes before injection. Another approach for analyte desorption is to place the stir bar in a small volume of a conventional HPLC liquid (or mobile phase) for HPLC analysis. The SBSE stir bars are trademarked as Twisters they can also be purchased from Gerstel. For more detailed information on SBSE technology, the reader is referred to two recent review articles.44 45... 

E. Bertol, F. Mari, and M. G. Di Milia, Programmable temperature vaporizer applications in an high-resolution gas chromatographic method for the quantitation of impurities in illicit heroin, J. Chromatogr., 466 384(1989). 

The reactor is heated by four infrared heating elements of 125 W each. The oven temperature is controlled by a programmable temperature controller (ALL Control AC 302). 

Banfi, S. and Bergna, M. (1999) Programmable temperature vaporizer (PVT) applied to the triglyceride analysis of milk fat. J. High Resol. Chrom. Commun., 22, 93-96. 

At SINTEF charcoals from birch and oak wood were produced at atmospheric pressure in a 3.7 L stainless steel retort placed in a Nabertherm muffle oven. The muffle oven is equipped with a programmable temperature controller, which provides control of the heating rate, temperature, and reaction time. The retort has a capacity of proximately 1 kg of dry wood per batch. The typical dimensions of the feedstock pieces were 3 cm x 3 cm x 5 cm. During heating and cooling, the retort was purged with Nj to prevent air leakage into the system. 

Layers often require heating after applying the reagent in order to complete the reaction upon which detection is based and ensure optimum color development. Typical conditions are 10-15 min at 105-110°C. If a laboratory oven is used, the plate should be supported on a solid metal tray to help ensure uniform heat distribution. A plate heater (Fig. 2), which contains a 20 X 20-cm flat, evenly heated surface, a grid to facilitate proper positioning of TLC and high-performance TLC plates, programmable temperature between 25°C and... 

For this reason, in this study we applied different thermal and hydrothamal treatments to analyze their effects on the structural and textural properties of the catdysts. Part of the catalyst was reduced in a Nj-Hj (9 1) stream at programme temperatures increasing linearly up to a final value between 503 and 773 K, for 1 h. A second portion was heated to 503 K in a pure hydrogen flow (50 cm min ) or in a Hj-H O mixture (prepared by introducing 1 pi pulses of water every 6 min. for 1 h). 

Special features/comments on-line evaporation cleavage from support on the instrument, collection of products in custom block ( waste cube ) 4 zones with individually adjustable temperature and individually programmable temperature gradients temperature/time programs possible automated version available... 

In SFE-GC coupling, the main fiictor to be considered is the flow rate of the fluid, which increases upon depressurization by a frtctor of about 400. The interfiK es used in SFE-GC are typically based on a split/splitless injector, an on-column injector or a programmable temperature vaporizer (45-57). In principle. 

In large volume injection, the programmable temperature vaporizer (PTV) has been the most popular technique, although also on-column injection can be applied, if the sample extract is sufficiently clean. 

LVDV-111+ rheometers were used with LV-4 spindles and SP-7Y Quick Connect Couplings. The reaction mixtures were contained in SC4-13RD disposable sample chambers. Brookfield Thermoses " heaters with Programmable Temperature Controllers were used and the epoxy cures studied at (1) 50°C and (2) 60 C. The control and data acquisition algorithm was run through a Rheocalc software program. 

RVDV-111+ and RVDV-11+ Pro instruments were used with SC4-27 disposable spindles, SC4-13RD disposable sample chambers, Thermosel heaters, and Programmable Temperature Controllers. These experiments were performed at 60°C. The spindles were held in a chuck, which was easily tightened and loosened by hand. Two reaction batches were prepared. The first batch was transferred into chambers "A" and "B" and promptly tested. The second batch was prepared after the completion of the first set of analyses, placed into chambers "C" and "D," and tested. Aliquots "A" and "C" were analyzed with the RVDV-II+ Pro and Wingather software, while "B" and "D" were monitored with the RVDV-III+ and Rheocalc software. 

For quantitative analysis, Bertol et al. (1989) found that a programmable temperature vaporizer inlet increased the accuracy of the analysis since it eliminated discrimination problems when analyzing compounds with a large range of molecular weights. With this method it was possible to increase the accuracy of the quantification of heroin, monacetylmorphine, acetylcodeine, papaverine, and narcotine commonly found in street samples of heroin. 

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