1) Turn on the helium tank. Open the valve (red circle) all the way.

2) Turn on the deionized water valve (arrow). Open the valve all the way counterclockwise. The valve is made of Teflon, a very soft plastic. Do not force it!

3) The float (red circle) in the flow meter should rise to the top of the meter column.

4) Turn on the column oven and the conductivity detector switches (red circles). Normally the other modules are powered by the oven, unless someone has been fooling with the switches. At this stage, the pump, conductivity detector, eluant generator, oven, and autosampler should all be on (P, CD, EG, O, A).

5) On the front panel of the pump, press MENU, 8, 7. This lets you monitor the LEFT and RIGHT 'P-POINT' values when the pump is running.

6) Turn on the computer and the printer. On the computer, start the RUN program.

7) On the main menu bar of the RUN window choose FILE, SELECT METHOD. Choose the proper method (usually 'Anions in natural waters'), and agree to whatever the window asks. The pump should start. For this GP50 pump the LEFT and RIGHT P values should settle down to ~10 units difference within a few minutes. If it doesn't, you need to get the bubbles out of the pump head.

8) Get all of your samples ready. On the computer, start the SCHEDULE program.

9) The schedule is a list of all of your samples, plus calibration standards, plus a few other things. First should be three or so test samples. They can be a standard or unknown or a mix. Their purpose is to let the columns flush out and to make sure everything is working OK. Next should be the standards. Under "Sample Type" these are listed as calibration standards 1, 2, 3, and so on. The numbers refer back to the component table in the Method, which is selected in the widest column. Immediately after the standards should be deionized water, just to make sure the standards are washed out. Next are your unknowns, which can be assigned dilution factors if they have been diluted. Last are two samples to finish things up: one standard to make sure everything went OK, and one deionized water. The method for the deionized water should be 'Stop Anions.met'. This method will turn off the pump and other electronics at the end of the run. Save this schedule with the name 'Anions' followed by today's date (don't use slash marks).

10) Load your samples into the autosampler racks. The first sample should be right most next to the black dot (yellow circles). Sample order should be like that below. The numbers below refer to the row numbers in your schedule (see above), not any sample numbers you may have written on your unknowns. Notice that the last sample (deionized water) has its top pressed down only part way using the other end of the cap pusher.

 

11) Load the autosampler with the racks. The first rack should be in the front, dots to the right.

12) Press the Hold/Run button on the autosampler (red circle) so that the green light is lit on the Run side. This puts the autosampler under computer control.

13) On the main menu bar of the RUN window choose FILE, SELECT SCHEDULE (circled in red). Choose the proper schedule (the one you just saved), and agree to whatever the window asks. Press the start button (circled in yellow) to start the run. Listen for the autosampler to start humming. Sample should inject at 2.30 minutes. Watch the chromatograph as it comes out on the screen. Keep an eye on the test samples to make sure the chromatograph looks good.