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June 2009 | Volume 7| Issue 3          

FEATURE ARTICLE:

Webinar Now Available OnDemand
Complying With the Modifications to
EPA Method 1664A

If you missed the recent live webinar about the modifications to EPA Method 1664A, it is now available OnDemand.

Learn more regarding: Why the modifications were made. How the modifications will affect your laboratory. How to optimize your automated sample preparation system. New SPE disk technology designed specifically for this modification. Q&A session, and more ... This OnDemand webinar also includes real-life accounts demonstrating how customers quickly and easily adapted to these modifications, ensuring maximum laboratory capability and productivity.

PRESENTERS: Michael Ebitson Applications & Technical Support Manager Jay Rowden Technical Sales Representative, South-East Region

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Click here to go to the ISC web site to download the OnDemand webinar.

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TECH TIP:

Cleaning and Replacing the Elute Check Valve
For all SPE-DEX Automated Extraction Systems

The Elute Check Valve Assembly (Figure 1) elutes the rinses into the collection vessel. The Check Valve Assembly components include a spring, a ceramic ball that sits on the spring, the seat, and a washer (Figure 2). When not in use, the check valve ball can stick, preventing the elution of solvents into the collection vessel. Prior to beginning an extraction, free the Check Valve by using the Check Valve Tool (PN: 02-0725 for the 1000/3000XL Extractors, or PN: 02-0727 for the 4790 Extractors).

CLEAN: Dirt or debris can enter the Check Valve and get lodged between the ball and the seat. When this happens, an open pathway is created that allows all liquids to drip through the Check Valve and into the collection vessel during other steps in the extraction process. To clean the Check Valve, follow the instructions below.

1. Attach a 125 mL collection vessel to the extractor station with the leaking Check Valve.
2. Insert a Disk Holder Cup with the support screen into the platform opening.
3. Fill the Disk Holder Cup with warm water.
4. 1000/3000XL: Go to the Status screen of the Controller and select the extraction station. Use the Drain key followed by the Elute key to drain the water into the collection vessel. Continue this process by flush lots of water through the Check Valve, remembering to empty the collection vessel as it fills. This should clear the Check Valve of dirt and debris.
5. 4790 Extractors: Use the Abort and Purge keys on the extractor keypad to activate the check valve. Press the Abort key first and hold it down while pressing the Purge key. With both keys held pressed, the run light will come on and activate the check valve. You can let go of the keys once the run light has come on.
6. REPLACE: If the Check Valve continues to leak, disassemble it to clean the internal components. Remove the three screws at the bottom of the Check Valve. These screws hold the Check Valve Assembly into the Collection Vessel Adapter Taper (Figure 1). Note the opening toward the back. This is the vacuum opening, which supplies vacuum to the collection vessel. The vacuum opening is aligned with the vacuum opening on the Collection Vessel Adapter Taper.
7. Once the screws have been removed, try pulling the Check Valve Assembly out from the Adapter Taper. The Check Valve Assembly may be stuck and difficult to remove. In this situation, use a flat edged blade and gently ease the Check Valve Assembly out by placing the blade between the Check Valve base and the Adapter Taper. Be careful not to score or damage the Teflon Adapter Taper.
8. . Remove the top cover of the assembly. Be careful not to lose any of the components. Remove the internal components of the assembly. Note the order of the components and the orientation of the seat (the countersink is toward the ball). Clean the components and verify that the spring is in good condition.
9. Reassemble the Check Valve and insert it back into the Adapter Taper of the extractor. NOTE: The small vacuum opening (see figure 1) must be on the left when facing the unit and align with the vacuum opening on the Adapter Taper. If the vacuum openings are not correctly aligned, no vacuum will be supplied to the collection vessel and therefore the solvent rinses will not elute.
10. Test the Check Valve by pouring some water into the Disk Holder Cup and observe if it leaks the from the bottom luer. If the leak persists replace the Check Valve with a new one.
    
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