Embedded Files
PROCEDURAL VIDEOS TO WATCH:
PROCEDURAL VIDEOS TO WATCH:
CHEMICALS PROVIDED (FOUND ON THE SHELF UNLESS OTHERWISE NOTED):
CHEMICALS PROVIDED (FOUND ON THE SHELF UNLESS OTHERWISE NOTED):
REQUIRED VOLUMETRIC GLASSWARE:
REQUIRED VOLUMETRIC GLASSWARE:
50-mL volumetric flasks (4)
25-mL volumetric flasks (4)
5-mL volumetric pipets (4)
SPECIAL EQUIPMENT (FOUND ON THE SHELF UNLESS OTHERWISE INDICATED)
SPECIAL EQUIPMENT (FOUND ON THE SHELF UNLESS OTHERWISE INDICATED)
pH meter (found on the shelf above the balances)
100-1000 µL adjustable micropipetter (on the bench next to the sink)
PROCEDURE:
PROCEDURE:
A. Preparation of the Eluent (IC mobile phase)
NOTE: The eluent should be made on the same day as the data acquisition.
Obtain an empty IC eluent bottle and cap. (This should be on the top of the IC instrument - see image below.) Rinse the bottle several times with tap water, followed by 2-3 rinses with RO water.
2. Fill the bottle to the 1000-mL line with filtered ultrapure water (found on the shelf in the cabinet).
3. Add ~0.339 g of sodium carbonate (Na2CO3) and ~0.084 g of sodium bicarbonate (NaHCO3). Put the cap on the bottle and shake well to dissolve the solids. This is your eluent (mobile phase).
4. Use a pH meter to measure and record the pH of the eluent solution (using pH 7 and 10 buffers for the calibration). The eluent pH should be in the range of 10.1 to 10.5.
B. Preparation of Standard Solutions
Obtain 1000 mg/L stock solutions of all five anions (fluoride, chloride, nitrate, phosphate, and sulfate).
Use four 5-mL pipets and four 50-mL volumetric flasks to make new stock solutions of each anion except sulfate, using ultrapure water for dilution. Use the following table as your guide:
3. Obtain four 25-mL volumetric flasks and label them A through D. Using the four standards solutions you created above, and the 1000 mg/L sulfate standard, use a micropipetter to create four calibration standards as shown in the following table, again using ultrapure water for dilution. (Be extra careful here - it is very easy to make a mistake.)
Standard Prep Summary
C. Sample Preparation
Pour at least 25 mL of tap water into a clean, dry beaker. Also obtain an IC unknown sample from me. There is no further preparation required for either.
D. Instrument Preparation.
Bring flasks A, B, C, and D, your tap water sample, your unknown sample, and your eluent buffer to the IC instrument.
Check that the levels of H2SO4 and water in their respective bottles on top of the IC Separation Center are at least 1/3 full. Let me or a TA know if they need to be refilled.
Connect your mobile phase container to the instrument pump (see below). If there was another bottle in place already, remove it, cap it, and set it in the spare location to the right.
4. Clamp and tighten the tubing on both the autosampler peristaltic pump and the IC Liquid Handling Unit peristaltic pump (see circled clamps below in their tightened state; the black lines should match up).
5. Switch on all the components. There are five switches in all, four are highlighted in the figure below and the fifth is on the back of the autosampler.
6. Check the IC Interface power light. If the light is flashing 30 seconds after the power has been turned on, flip the switch off, wait 10 seconds, then turn it back on.
E. Setting up the Software
Open the IC Net 2.3 software by double-clicking the icon on the desktop. Log in as musa with a password of musa. Close any windows that may be open from the previous user except the System state window. You can close the billboard by right-clicking on it and selecting Z.
From the File menu, select Open, then System. Select the Concordia folder and then open Chem 330. A system screen like the image below should appear. This window is your main workstation, so make sure not to close it until you have run all your samples.
3. Under the Control menu, select Connect to Workplace. When the system is connected, select Startup hardware (Measure baseline) from the Control menu. You should now see a white window pop up that looks like the start of a chromatogram. (See the image below.) This is your baseline window. If this window does not open simply click Startup Hardware (Measure baseline) again.
4. Find the tubing bundle on the left side of the Separation Center. Check to see that there is solution emerging from the water waste, acid waste, and eluent lines. If nothing is coming from the acid and/or water waste lines, you may have to tighten the clamp on the peristaltic pump another click or two.
5. Double-click on the IC Separation Center (the circled part of the image under step 3 above). This will open up a window that you will use to level your baseline by regenerating the suppressor. Once the window is open, wait for your baseline to become fairly level, then click the Step button to begin regenerating the next channel of the suppressor. Wait 5 minutes to make sure the chromatogram baseline is stable and at a fairly low level of conductivity. (Don’t worry if it’s not zero, since it varies with each mobile phase that we make.) Continue to click Step every 5 minutes or so until the start of data collection to ensure that each channel of the suppressor is ready.
6. Now you must check the autosampler flow rate to the IC injection valve. Take the Sample waste line (not Excess Sample) from the bundle on the side of the Separation Center and place it into the 10-mL graduated cylinder on the nearby ringstand. Move the autosampler needle to a rinse position to manually pump rinse water. Do this by double-clicking the autosampler image on the system screen. Click the Manual tab on the 838 Advanced Sample Processor window, then the Autosampler tab (see figure below). Make sure the autosampler needle is in the up position, select the Rinse 1 position from the Move menu,then click Start to move the needle.
7. Select the Work (Down) option from the Lift position menu, then click Start to move the needle into the solution.
8. With the on option selected in the Pump line, click Start to begin pumping. You should see the pump on the autosampler begin to operate.
9. Make sure that liquid is flowing from the sample waste line into the graduated cylinder. The rate should be approximately 1 drop per second. Tighten the clamp on the peristaltic tubing if the rate needs to be increased.
10. Click Stop to stop the pump, move the Lift position to Shift, and click Start to lift the needle.
11. Place the sample waste line back in the bundle, and empty the liquid from the graduated cylinder
12. Obtain six clean, dry autosampler tubes and label them A, B, C, D, Tap water and Unknown. Fill the tubes with the appropriate solutions. Place the tubes in the autosampler tray, taking note of the position number for each of the tubes. (Be sure you are identifying the position numbers correctly.)
13. Now back on the System window, click the System menu and select Sample Queue. Enter a filename unique to you (record this in your notebook), then click Open. Click Edit on the run order window that appears. This should bring up a spreadsheet-like window (see below) from which you can enter your samples and select the run order.
14. Highlight the first row by clicking on the number 1, then choose Edit → Duplicate row(s) and repeat this five times so that you have a row for each vial. Now under the Ident column, enter a name for each of your solutions. Under the Vial column put the appropriate number corresponding to the position on the autosampler. Your window should look similar to the image below. Click the green checkmark (circled in the image) to close and save your run order. You should now be returned to your run order window with your new run order listed. Leave this window open.
15. Do NOT click Start yet! If you haven’t clicked the Step button for your baseline at least three times, then finish doing so now. If your baseline is not level, click Step again and wait 5 more minutes. Continue stepping until the baseline is level.
F. Acquiring the Data
Once your baseline is stable, make sure there are no other methods or chromatograms running besides your baseline, then click Start on your sample run order window.
Note: If other methods are running it will stop those methods and start your method as soon as you hit start. This can cause a problem for both you and whoever is running the method you just interrupted. Their method will not be finished and whatever sample they had running through the system will now most likely come out in your chromatogram because it’s still in the system. This only applies when more than one group is running the machine in one lab period or day.
The autosampler should now be lining up for the injections. Make sure you can see the level of liquid in your first sample tube dropping when the needle is attempting to pull solution from it. If not, increase the tension on the tubing slightly by tightening the plastic clamps until there is solution coming through.
A new white chromatogram window showing a running baseline should appear. This window will only run for the amount of time it takes the autosampler to inject your sample. Then a new light blue chromatogram for your injection will appear (see below). The system is now set to run your samples in the order you specified. Now just sit back and relax. (This is a good time to catch up on your notebook.) Don't leave the system unattended for large periods of time! (The tubing on the IC liquid handling unit has been known to pop off if the clamp is too tight.) Contact me or a TA if you see anything that appears out of the ordinary.
5. After each run is complete, you will be prompted to save the chromatogram report in a pdf format. If, for some reason, you are not prompted to save, you can select the chromatogram at any time, and click on File – Print. You should then be prompted to save the report. Reports will show all the peaks in the chromatogram and the calculated area for each peak. These reports should be uploaded to your Experimental page in LabArchives.
G. Shutting Down the Instrument
Once all your samples have been run through the system, go back to the system menu window and under Control click Shutdown Hardware. Wait until you hear and see the IC pumps shut down, then click Disconnect from workplace.
Release the clamps on the peristaltic pumps and close the IC software on the computer. (If prompted to save the changes made, click No).
Turn off all five power switches on the instruments.
H. Waste Disposal / Clean Up
Pour your leftover buffer down the drain.
Pour your autosampler vials down the drain and rinse them several times with RO water. Use acetone to wash off any markings. Put them on a drying rack to dry.
Pour any leftover standard solution down the drain. Return used sample or standard containers to the labeled bin in the prep hood.
Place all used pipets in the "Pipets to Be Washed" bin. Rinse all volumetric flasks 5-6 times with tap water and then 2-3 times with RO water, and return to the shelf. (Use acetone to wash off any markings.) Similarly rinse all glassware from your drawer and return it to your drawer.
Use the sponge in your drawer to clean your bench area.
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