Types of Concentrators

There are three different types concentrators in this lab. The main two you'll be working with are these:

[insert picture of concentrators here; combine into one image file if possible]

OI Analytical 4560 Concentrator

We're slowly replacing these concentrators because it's so old that you can't buy replacement parts for it anymore. In some ways though, it's easier to use than the newer ones. The main functions you need to know are:

• Start: Don't press this unless the concentrator is on Hold. If you want to desorb a sample, position and run a line from the sequence on the computer and it'll desorb automatically when the GC/MS is ready.
• Hold: Pressing this once will stop the concentrator. You do this when you need to restart the computer, the MSTOP program, or you don't want to desorb the sample that just purged.
• Bake: This will bake out anything that's in the trap. To get here, you press Hold and cycle to Bake by pressing the ON/OFF arrows.
• Purge Ready: The concentrator is ready for sample collection. When this screen pops up, the concentrator automatically sends a signal to the autosampler to grab the next vial in the tray.
• Desorb Ready: The concentrator is done with sample collection. The GC/MS will automatically send a signal to the concentrator to desorb the sample when it's ready to be analyzed.

OI Analytical Eclipse Concentrator

This is the newer concentrator we're swapping to. Unlike the other concentrator, this one is operated entirely by a touch screen and has a lot more functions and settings. It looks overwhelming at first, but there's not much to memorize. It functions largely the same as the old one, but the functions are hidden under different names.

• Pause: The pause button functions the same as the Hold button on the old concentrator. The touch screen isn't very responsive though, so it might take a few tries for pausing to register. If it registers, the concentrator will say [State] - Paused (ex: Desorb Ready - Paused).

I generally don't recommend pausing on this concentrator if you're running QC for the day because pausing causes the next sample purge to have really low recoveries for the alcohols. This is especially a problem if you pause before running L/C for the day because the RPDs won't pass.

• Bake: To bake the trap, you have to tap Abort on the top screen of the concentrator, then go to Maintenance > Manually Advance State > Bake. To stop baking, tap Abort and the concentrator will automatically revert to Purge Ready.

The concentrator doesn't set a timer for baking when you manually advance it, so you have to keep track of how long it's been baking.

Teledyne Tekmar Solatek

This concentrator is only used on F4. All controls for this are in the Solatek program on the computer.

Maintenance

As with all machines, the concentrators are periodically maintained to ensure consistent performance. The type of maintenance depends on the specific concentrator.

Changing Trap

The primary maintenance you'll be performing on the concentrators is changing the trap. We change the trap for two reasons:

1. We're running an ICAL.
2. Compound recoveries are low (see Troubleshooting).

4560 Concentrator

1. Turn off the concentrator. Let it cool down before proceeding.
2. Open the cover. Remove the shield covering the trap. [pic]
3. Get a wrench and unscrew the top and bottom bolts on the trap. [pic]

Either the 3/8 or the 10mm wrench work for this.

4. Remove the old trap.
5. Place the new trap, making sure the side with the black piece is facing down.

If you install it the wrong way, the trap will burn and you WILL smell it. [pic]

6. Tighten the trap screws by hand into the concentrator. When you can't tighten the screws further, use the wrench to fully tighten them. Do not overtighten the screws or you may end up damaging the trap.

I usually tighten the bottom screw first since that one tends to be harder to thread properly.

7. Replace the shield and close the trap door before turning the concentrator back on.

Eclipse Concentrator

1. Turn off the concentrator. Let it cool down before proceeding.
2. Open the cover. Remove the shield covering the trap. [pic]
3. Get a wrench and unscrew the top and bottom bolts on the trap.

Either the 3/8 or the 10mm wrench work for this.

4. Remove the old trap.
5. Place the new trap, making sure the side with the black piece is facing down.

If you install it the wrong way, the trap will burn and you WILL smell it. [pic]

6. Tighten the trap screws by hand into the concentrator. When you can't tighten the screws further, use the wrench to fully tighten them. Do not overtighten the screws or you may end up damaging the trap.

I usually tighten the bottom screw first since that one tends to be harder to thread properly.

7. Replace the shield and close the trap door before turning the concentrator back on.

Solatek

1. Turn off the concentrator. Let it cool down before proceeding.
2. Get a rod to prop the cover up. [pic]
3. Use a screwdriver to remove the side cover. [pic]
4. Unscrew the top cover to access the nuts holding the trap in place. [pic]
5. Unscrew the two bolts holding the trap in place.
6. Remove the sleeve from the old trap.
7. Replace the sleeve onto the new trap and reinsert the trap into the concentrator.

Make sure the open end is fully inserted before tightening the trap screw. If it's not, your recoveries are going to be low when you run tests.

8. Replace the top and side covers before turning the concentrator back on.

Changing Water Management (4560 only)

1. Lower the valve and transfer line temperatures to ~40°C (just enough so you can touch it without burning yourself). [pic of where to find settings]
2. Turn off the concentrator, then remove the concentrator cover and valve cover (if needed). [pic]
3. Use a 1/4-in. and a 7/16-in. wrench to unscrew the transfer line connecting the water management to the valve. [pic]
4. Remove the sensors inside the water management. [pic]
5. Remove the trap.
6. Remove these nuts using a wrench. These hold the water management in place. [pic]

Do NOT lose the insulator. We don't have replacements for this. [pic]

7. Remove the water management from the concentrator. Loosen the hex bolts and remove the water management from the shield.
8. Remove the square insulator from the water management (you can use a wrench for this or remove it by hand). [pic]
9. Replace the square insulator and shield on the new water management.
10. Reinsert the water management into the concentrator and replace the insulator and nut before tightening.

The square insulator needs to be placed so that when you reinsert the water management into the concentrator, this part faces straight up (or at least as straight as you can manage).

12. Reinsert the trap.
13. Reinsert the screw for the transfer line into the valve. Make sure there are no gaps when reinserting the screw.

I find it easier to thread the screw while you're still behind the concentrator since it's easier to see what you're doing.

This part tends to be the spot where you find helium leaks later. This is why it's important to check for gaps.

14. Reinsert the temperature sensors into the water management before tightening the nut on the top of the transfer line.

You can't reinsert the temperature sensors once you replace the nut on top, so save yourself the hassle of redoing this by putting the sensors back first.

15. Run a test purge to test the purge flow and check for leaks using the leak detector.

Changing Transfer Line

This is normally done by Diem or Robert. We tend to do this as a last resort because transfer line wire is expensive.