NEWS IsoMist: The temperature of a sample introduction system has a profound effect on the performance of an ICP-OES and an ICP-MS. A cooled spray chamber is often used to reduce the volatility of certain solvents so that the plasma is sustained. Heating the spray chamber results in higher sample transport. Maintaining the spray chamber temperature can be critical when trying to achieve longterm signal stability. Figure 2a: IsoMist Programmable Temperature Spray Chamber The IsoMistTM Programmable Temperature Spray Chamber (Figure 2A) is a convenient and universal device for both controlling and monitoring the spray chamber temperature. The temperature is electronically controlled using a powerful inbuilt Peltier device, allowing the ICP analyst to select any temperature between -10oC and +60oC in 1oC increments to provide the optimum conditions for any application. Unique to the IsoMist is a Twister spray chamber encapsulated with a temperature conductive resin (Figure 2B). The encapsulated spray chamber provides a uniform temperature from top to bottom and an air tight fit within the IsoMist module to prevent condensation build-up and freezing (Figure 2C). These unique features of the IsoMist allow for a stable temperature to be held within +/- 0.1oC and a temperature of -5oC to be reached within 15 minutes. Other Tracey cyclonic spray chamber: The Tracey cyclonic spray chamber is Glass Expansion’s standard glass cyclonic spray chamber (50 mL volume). It gives the best sensitivity and lowest memory effects for standard ICP analyses. The typical application uptake range is 0.2 to 3.0 mL/min. Twister cyclonic spray chamber: The Twister cyclonic spray chamber features a central transfer tube which acts as a secondary droplet filter to reduce the mean droplet size. This reduces solvent load in the plasma without compromising detection limits, while improving precision (% RSD). The typical application uptake range is 0.2 to 3.0 mL/min. Low volume spray chamber: Glass Expansion offers two low volume spray chamber designs, the CinnabarTM and TwinnabarTM . The advantage of a low volume spray chamber is to provide a very fast washout for sample uptake rates in the range of 20 to 400 μL/min. The Cinnabar is a minicyclonic based on the Tracey design while the Twinnabar is minicyclonic based on the Twister design. Like the Twister, the center baffle of the Twinnabar offers a reduced solvent load and excellent precision, in addition to a very fast washout. PTFE and PFA spray chamber: In 2006, Glass Expansion released a new line of PTFE and PFA spray chambers which have an internal surface that is specially treated using a proprietary process, named StediflowTM , to improve the wettability of the surface and provide consistent drainage. Without the Glass Expansion Stediflow treatment, droplets tend to form on the surface and degrade both sensitivity and precision. Glass Expansion offers two styles of HF-resistant spray chambers, the Tracey TFE and PFA44. The Tracey TFE is made from PTFE (Teflon) which is more chemically resistant than the old polypropylene HF-resistant spray chamber. The Tracey TFE spray chamber can be teamed with the DuraMist HF-resistant nebulizer to form the ideal chemically inert sample introduction system for ICP-OES. The Tracey PFA44 is made from ultra-pure PFA to provide exceptional purity and excellent sensitivity for ICP-MS techniques. The PFA44 spray chamber can be teamed with the OpalMist PFA nebulizer to form the highest purity, most inert sample introduction system available. A Tracey PFA44 spray chamber molded specifically for an airtight fit within the IsoMist module, is provided to those customers who require an HF-resistant temperature controlled option. Further details on the IsoMist are covered in the following section. Figure 2b: IsoMist Glass Twister Spray Chamber encapsulated in conductive resin www.geicp.com Glass Expansion Newsletter | Issue 35 2
GE0283 GE Newsletter October 2014
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