SPDE - option for volatile components - Alpha MOS - #1

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CHROMTECH CHROMTECH GmbH • Buchwiese 3 • D-65510 Idstein, Germany • +49-6126-1686 • www.chromtech.de • .07/2004 CT-SPD_EC-2004_B SPDE Extraction Cooler – A SPDE-option for volatile components Since the introduction of SPDE. different users had the desire to be able to extract volatile substances even better. Since the SPDE syringe needle usually works at ambient temperatures or at sample temperature during the extraction, volatile substances are poorly extracted, compared to less volatile components. That is a limitation for SPME too. On the contrary to this method, SPDE. will accomplish those applications by means of intensive needle cooling! With use of the SPDE Extraction Cooler very volatile components can easily be extracted without any problems. Figure 1 shows a schematic drawing of the extraction cooler, basicly by using a Peltier-cooler for the SPDE needle. The cooler is installed on top of the CHROMTECH single magnet mixer (SMM) (fig. 2) and reaches temperature differences of up to 40°C. This means the needle can cool down to -15°C while working at an ambient temperature of 25°C. Figure 3 shows how effective the cooler is when comparing this example of MTBE (methyl tertiary butyl ether). TM Fig. 2: The SPDE - Extraction Cooler is simply mounted on top of a Single Mixer. The SPDE needle penetrates the vial only by a few millimeters. Fig. 2: Principle of the automated SPDE extraction. The analyte is enriched by controlled pumping through the specially coated syringe needle. Extraction Cooler: The analyte is cold trapped inside the SPDE needle then thermally desorped. During enrichment the sample is heated while the needle is being cooled. Gasflow Syring with needle coated inside liquid sample headspace sample Hot Injector GC Column Extraction of Liquid or Headspace samples Desorption into hot Injector Fig. 3: 0,9 ìg/L MTBE by SPDE Extraction Cooler (-15° C) and without cooling (ca. 25°C. Each sample was incubated at 50°C. -15°C Ambient °C