Instruction for Direct Inlet Mass Spec Use
1. Place the sample in a melting point capillary tube. Only a few crystals are necessary.
2. Place the capillary in the sample holder, then remove the capillary and cut it so no glass is exposed above the sample holder. (This is about one cm..)
Use cotton gloves when touching the sample holder to avoid dirt build up.
3. Screw the sample holder into the end of the direct inlet probe. Make sure the heating wire is connected to the probe.
4. On the computer, at the top level, select Data Acquisition, and change the Inlet from gc to DIP (which stands for Direct Insert Probe), using the menu selection.
5. Select Edit Acquisition Parameters. Set Solvent Delay = 0.0. Set the mass limits you want, e.g. 30 - 300, or 30 - 200.
6. Using the Edit Temp. Zones, program the temperatures as you would for a gc run. The ion source, need not be very hot;120o or even lower is fine. The temperature programming is for the direct inlet probe itself. Unlike gc programming the rate/min = 0.0 is the fastest temperature increase you can get. If you think you have a compound that will decompose then you can program step increases, use the insert level from the menu of the Edit Temp. Zone. e.g. start at 40° to 60° in the first step, then in the next level take it from 60 to80° etc. Then you can later sample the ms from each level to get a spectrum of the compound before it decomposes..
7. Press prepare to inject.
Now insert the direct inlet probe. Never insert or remove the probe when it is hot(>80°).
8. Remove the conditioner probe.
9. Insert the direct inlet probe to just ater the first set of markings and before the second set of markings (about two inches). This makes a seal.
10. Open the auxiliary valve (move to horizontal position) below the probe, and wait for the pressure on the auxilliary vacuum dial to pump down to .about 1 - 2.5 x 10-2 torr.
11. Open the main valve, and gently push the probe in until it won't go in any farther. You can see the probe entering the source through the window on top of the source.
12. Press GO, either by the remote button, or on the computer.
The Total Ion Chromatograph is handled the same way a gc trace is..
When you are done.
13. Pull the probe out of the source a little bit. (Look in the window so you can see the sample holder is total free from the ion source tube.) and allow it to cool below 80°. You can monitor the probe temperature from the Edit Temp Zone menu or the Prepare to Inject menu. If this is done as soon as the Total Ion Chromatograph is complete, it will be cool and ready to remove when you are done manipulating the spectrum.
14. With the chain connector attached, gently pull out the probe the length of the chain, then remove the chain an pull it out a little more to just beyond the first mark.
15. Close the main valve, and close the auxilliary valve.
16. Remove the probe, and replace the conditioner probe.
17. Unscrew the sample holder (gloves!) and replace in direct inlet kit. Place the probe back into its cover.