How do I install a capillary column?

To install a column follow the instructions below.

Pre Column Installation Check List

1 Replace oxygen, moisture, and hydrocarbon traps as needed.
2
Check gas cylinder pressures to ensure that an adequate supply of carrier, makeup, and fuel gases is available. Minimum carrier gas purity percentages are given in Table A.
3
Clean the injection port, replace critical injection port seals, replaceinjection port liners, and change septa as needed.
4 Check detector seals, and replace as necessary. Clean or replace detector jets as necessary.
5 Carefully inspect the column for damage or breakage.
6 Gather the necessary installation tools: You will need a column cutter, column nuts, ferrules, a magnifying loop, and typewriter correction fluid.

Installing the Column:

1
Uncoil approximately 0.5 m (18 in.) of tubing from the column basket at both ends of the column for injector and detector installation. Avoid sharp bends in the tubing.
2 Mount the column in the oven. Use the hanging bracket if available.
3 Install the column nut and Vespel or graphite ferrule at each column end; pull the nut and ferrule down the tubing approximately 5 cm.
4 Score (cut) the column. Score the column about 4 to 5 cm from each end.
5
Make a clean break. Grasp the column between the thumb and forefinger as close to the score point as possible. Gently PULL and bend the column. The column should part easily. If the column doesn't break easily, don't force it! Score the column again in a different place, try for a clean break.
6
Use a magnifying loop to inspect the cut. Make sure the cut is square across the tubing with no polyimide or glass fragments at the end of the tube
7
Install the column in the inlet. Check the GC manufacturer's instrument manual for the correct insertion distance. Mark the correct distance on the column with typewriter correction fluid. Insert the column into the injector. Finger tighten the column nut until correct insertion distance. Mark the it starts to grab the column, and then tighten the nut an additional ¼ to ½ turn so that the column cannot be pulled from the fitting when gentle pressure is applied.
8
Turn on the carrier gas, and establish the proper flow rate. Set head pressure, split flow, and septum purge flow to appropriate levels. See Table B for nominal head pressures. If using a split/splitless inlet, check that the purge (split) valve is ON (open).
9
Confirm carrier gas flow through the column. Immerse the end of the column in a vial of acetone, and check for bubbles.
10
Install the column into the detector. Check the instrument manufacturer's manual for. the proper insertion distance
11 Check for leaks. THIS IS VERY IMPORTANT. Don't even THINK about heating the column without thoroughly checking for leaks.
12 Establish proper injector and detector temperatures
13 Establish proper makeup and detector gas flows. Ignite or turn ON the detector.
14
Purge the column for a minimum of 10 minutes at ambient temperature (approximat1ely x column volumes).
15
Inject a nonretained substance to check for proper injector installation. Examples: butane or methane (FID),headspace vapors from: acetonitrile (NPD), methylene chloride (ECD), air (TCD), argon (mass spectrometer). Proper installation is indicated by a symmetrical peak. If tailing is observed, repeat the injector installation process.

Conditioning and Testing the Column:

1
Condition the column at 20?C above the maximum temperature of the analysis or at the maximum temperature of the column (whichever is lower) for 2 hours. IF AFTER 10 MINUTES AT THE UPPER TEMPERATURE THE DETECTOR SIGNAL DOES NOT BEGIN TO FALL, IMMEDIATELY COOL THE COLUMN AND CHECK FOR LEAKS.
2 If you are using Vespel ferrules, recheck tightness after the conditioning process.
3 Confirm final proper average linear velocity by injecting a nonretained substance. See Table Below
 
Table A
Dead Time for Common Capillary Column Lengths
Column Length, m Hydrogen (40 cm/sec) Helium (20 cm/sec)
10

0 min 25 sec

0 min 50 sec
15 0 min 38 sec

1 min 15 sec

25 1 min 02 sec

2 min 05 sec

30 1 min 15 sec

2 min 30 sec

50 2 min 05 sec

4 min 10 sec

60 2 min 30 sec 5 min 00 sec


 
 
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