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July 2009 | Volume 7| Issue 4          

   FEATURE ARTICLE:

 Enhanced Line of Consumables
 Ensuring Superior Performance

Proven quality Horizon Technology accessories, consumables and spare parts are thoroughly tested, and lot certified for performance and automation -- to ensure the best chemistry and that your automated sample preparation systems operate efficiently and increase your lab's productivity.
Expert advice We will help you select your accessories, consumables and spare parts, and answer any technical queries you may have. Everything from a single source One-stop-shopping for accessories, consumables, spare parts, and services, helping make your life easier, and simplify administration. Online catalog Soon you'll be able to browse our new, convenient Online Catalog for accessories, consumables and spare parts, and fast-track your order. Open 24/7 — email your order and we will email or call you with your quote.	Oil & Grease Consumables - Pacific™ O&G SPE Disks - Pacific™ Fast-Flow Pre-Filters - Oil & Grease Pans - Oil & Grease Sandard - Separatory Funnel    ... and more Organics Consumables - Atlantic™ SPE Disks - 3M Empore™ SPE Disks - Oasis® HLB Disks - Atlantic™ Fast-Flow Pre-Filters - DryDisk® Membranes - DryDisk® 50mL Barrels - EZ Seals - Dirty Sample Screens - VOA Vial Adaptors    ... and more
ONLINE CATALOG FAST TRACK YOUR ACCESSORIES, CONSUMABLES & SPARE PARTS ORDERING COMING SOON! Order Department: Corie McCarthy orders@horizontechinc.com 603-893-3663 ext:618	DryDisk® Separation Membrane 50 mL Disposable Barrel

TECH TIP: SPE-DEX® 4790 Automated Extractor System

Coating the Water Sample Inlet Valve to Prevent Vapor Lock

The Horizon Technology SPE-DEX® 4790 Automated Extractor Water Inlet Valve assembly is made of PTFE*. Due to the surface tension of water, and as the PTFE is not a very “wettable” surface, a phenomenon termed 'vapor lock' can occur.

When this happens, water from the sample bottle does not flow down into the disk holder during the sample-processing step of the extraction method, even if the valve is fully open. If the sample does not flow down quickly enough, or does not flow at all, the liquid level sensors warm-up and prompt the system to advance to the next step, air dry the disk, and then rinse. During the rinse steps, solvent shoots up into the bottle containing sample, which will break the vapor lock and cause an overflow.

To prevent this situation from occurring, the valve may be conditioned with an ST-100 hydrophilic solution. The solution increases the 'wettability' of the surfaces of the valve, preventing a vapor lock. The solution coating will lose its effectiveness over time, and the valve will need to be recoated, so incorporate the valve conditioning as part of your laboratory’s preventive maintenance program.

Download this complete Tech Tip including instructions on how to use the solution to coat the valve.

* (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene which finds numerous applications. PTFE is most well known by the DuPont brand name Teflon. PTFE is a fluorocarbon solid, as it is a high molecular weight compound consisting wholly of carbon and fluorine. Neither water and water-containing substances nor oil and oil-containing substances are wet by PTFE. PTFE is very non-reactive, partly because of the strength of carbon–fluorine bonds, and so it is often used in containers and pipework for reactive and corrosive chemicals.
Reference: Wikepedia

If you have any questions or require further information regarding this TECH TIP please contact: support-service@horizontechinc.com