3
Figure 1
b. Depress the syringe plunger; immediately following, press the white
Collect button on the Mini GC to begin data collection. Be careful not
to bend the plunger as you press it down. Pull the needle out of the
injection port immediately. As you withdraw the syringe needle, lift
straight up to avoid bending the needle.
c. While the data collection proceeds, repeat Step 4 to thoroughly clean the
syringe and needle. It may take more than three flushes to feel the
syringe plunger move smoothly again, which is your indicator that the
syringe and needle are both suitably clean.
d. The run will automatically stop after the allotted time or you can choose
to end it early if you are satisfied that all analytes have eluted
completely.
7. Name your sample appropriately. To do this, click or tap on the y-axis label.
Click or tap on Dataset Options next to the data set you wish to rename.
Click or tap Rename Data Set. Enter a name for the sample and click or tap
Rename.
8. Analyze your chromatogram using Add Peak Integral.
a. Select the peak of interest, if necessary.
b. Click or tap on Add Peak Integral,
. The retention time (min), area,
and % area will automatically appear below the graph. Rename “Peak 1”
to the name of the compound injected, if known, in the table.
c. Repeat steps a–b for additional peaks.
Note:
To adjust your selection,
drag the edges of your previous selection. To delete a peak selection,
click or tap the X in the upper right corner.
9. Click or tap on the File Menu to Save or Export your data.
Note:
If a peak
integration table exists, the data table is saved with the file. Export will not
have the information from the data table available.
the plunger. If the plunger is accidentally pulled out of the glass barrel,
reinserting it is extremely difficult, sometimes impossible. Never pull the
plunger back more than 50% of its total volume. Be careful not to bend the
plunger as you press it down. Do not remove the plastic spacer on the
needle.
a. Depress the plunger fully.
b. Submerge the tip of the syringe needle into the vial of acetone or n-
hexane.
c. Pull back the plunger to fill the barrel about 1/3 full of acetone or n-
hexane. Examine the barrel of the syringe and estimate the amount of
liquid in the barrel.
d. Expel the liquid onto a lint-free tissue or a paper towel.
e. Repeat Steps a–d at least two times, until you are comfortable pulling up
a liquid into the syringe and measuring the volume in the syringe barrel.
Use a lint-free tissue or a paper towel to carefully pat around the tip of
the syringe needle.
5. Follow the process in Step 4 to clean and flush the syringe with a sample,
such as pentane, to be injected into the Mini GC.
6. Once the Mini GC has reached the correct start temperature and pressure, the
indicator LED should turn green and the software will display a message
that reads, “Inject, then press collect button on device.” Collect 0.2 µL of
your sample, such as pentane, for injection.
a. To insert the needle of the syringe into the injection port of the Mini
GC, hold the syringe with one hand and steady the needle with your
other hand.
Important:
Supporting the needle guard and the lower part
of the needle with two fingers, as shown in Figure 1, can prevent the
possible bending of the needle. Insert the needle into the injection port
until the needle stop is fully seated. If the needle sticks, rotate it slightly
while inserting. Do not move the plunger yet.
