Hydrophilic Solution for Your Vapor Lock Dilemma

Have you ever put your water sample onto your Biotage® Horizon 3100 extractor and all your prewet/conditioning steps worked great and then suddenly, the water inlet valve opens, and nothing happens!  This can be terrifying because a lot is riding on those samples!  If you notice this right when it happens, a simple wiggle of the sample bottle should introduce air into the bottle releasing the water, in turn loading your sample.  However, you do not want this happening all the time, especially when you leave your extractor for a while, come back, and see that your sample never loaded!

Vapor Lock

This phenomenon is called a vapor lock.  The water inlet valves are made of materials which are non-polar.  Since water is polar, it is naturally repelled by the non-polar materials and will not go through the water inlet valve.  Instead, it will stay inside the sample bottle, defying gravity!  However, there is a simple fix that can be done to prevent this from happening to you.

Hydrophilic Solution

If this has ever happened to you, I am sure you were informed about hydrophilic solution (P/N 165-0712) which is a polyvinyl alcohol solution.  This is a very important preventative maintenance step that should be done every 60 to 90 days (depending on sample throughput) to prevent vapor lock from happening.  The solution works by coating the sample flow path of the water inlet valve with the polar coating contained within the hydrophilic solution.  With this coating applied, the sample will flow right through the water inlet valve no longer defying gravity by staying in the upside down sample bottle.

Now you are asking, well how do I complete this preventative maintenance task?  For your convenience, we have broken out instructions by extractor models below.

SPE-DEX 1000XL or 3000XL

  1. Place a piece of tape over the left hole on the bottom of the bottle holder.
  2. Lower the bottle holder and place the water inlet valve onto the arm as shown, inserting the downtube into a plastic vial.
  3. Open the water valve by rotating the driveshaft fully clockwise.
  4. Fill the valve to the top with Hydrophilic Solution.
  5. Open and close the valve using the driveshaft to ensure that all parts are coated.
  6. Leave the valve open part of the way and allow it to soak for at least 2 hours.
  7. After the two hours, discard the used solution and remove the tape from the valve.
  8. Flush the valve using DI water while opening and closing the valve to ensure that all wetted areas have been rinsed.
  9. Using the water inlet valve, run at least (2) purges of the instrument to ensure that all wetted areas have been rinsed.

Biotage® Horizon 3100 (formerly SPE-DEX 3100)

  1. Place a piece of tape over the bottom of each rinse rod on the water inlet valve which will be treated.
  2. Insert the downtube into a plastic vial and place the assembly onto one of the bottle holders on the instrument.
  3. Open the water inlet valve by rotating the driveshaft fully clockwise.
  4. Fill the valve to the top with hydrophilic solution.
  5. Open and close the valve using the driveshaft to ensure that all parts are coated.
  6. Leave the valve open part of the way and allow it to soak for at least 2 hours.
  7. After the two hours, discard the used solution and remove the tape from the valve.
  8. Flush the valve using DI water while opening and closing the valve to ensure that all wetted areas have been rinsed.
  9. Using the water inlet valve, run at least (2) purges of the instrument to ensure that all wetted areas have been rinsed.

Important to note on 1000, 3000 and 3100 Extractors

  • Be sure not to use acetone because the 3100 water inlet valves are not compatible with acetone!
  • It is very important that the hydrophilic soak is done at the very least every three months because it will keep your water inlet valves working in tip-top shape!

SPE-DEX 4790

  1. Slide the thermistor clip down and off of the downtube.
  2. Place a plastic vial over the end of the downtube.
  3. With the nitrogen source on, and the extractor pressure correctly regulated to 35-50 psi, load and run the Envision method entitled “Sample Drain”. This method is available within the current method dropdown and will open the water inlet valve.
  4. With the sample valve open, fill the water inlet valve using hydrophilic solution until the liquid level is just below the bottle holder O-ring (see below).
  5. Cycle the water inlet valve using the sample drain method making sure to pour more hydrophilic solution into it if needed.
  6. Allow the valve to soak for at least 2 hours.
  7. After the two hours, remove the vial and drain the fluid into a beaker. It will be necessary to use the sample drain method to fully drain all of the solution.
  8. Slide the thermistor clip back onto the downtube and adjust to the proper height using the sensor height adjustment tool.
  9. It is recommended that the user runs 2, 1 L aliquots of DI water using their extraction method to ensure that all wetted areas of the valve are flushed by both water and reagents.

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