12 Injection Port
12.3 Removing and inserting the glass insert
Q Tool requied
Fig. 12.3.1 Wrench for Glass insert nut (P/N 221-46977)
Q Removing the glass insert
The glass insert should be removed carefully to avoid breakage.
(1) Hold the septum nut and remove the glass insert nut from the injection port. Lift the septum nut straight up and move it out of the way.
WARNING
Risk of burns.Do not perform injection port maintenance until the injection port tem- perature has dropped below 50°C .
CAUTION
Wait until the injection port has cooled to loosen screw and nuts to prevent them from binding.
CAUTION
It is important to hold the septum nut while removing the glass insert nut. Otherwise, the gas tubing can pull out the insert, and the septum nut can break the insert.
Septum nut
12 Injection Port 12.3 Removing and inserting the glass insert
(2) Use tweezers to remove the glass insert.
Fig. 12.3.3
Glass insert
12 Injection Port
12.3 Removing and inserting the glass insert
Q Attaching a fluoride rubber O-ring
Use a fluorid rubber O-ring when the temperature of the injection port is 350°C or less. Attach the fluoride rubber O-ring as shown below and inset the glass inset in the injection port.
Fluoride rubber seals the injection port better than graphite, and is normally used. However, it tends to deteriorate and leak over prolonged periods at high (>350°C) temperatures. Check frequently for leaks.
Ensure that the inset is touching the bottom of the injection port. This will place the O-ring 3 mm from the top of the insert.
Q Attaching a graphite O-ring
Use a graphite O-ring when the temperature of the injection port is 350°C or higher. Attach the graphite O-ring shown as below and insert the glass insert in the injection port.
Although graphite O-rings are recommended for high temperatures, the sealing ability of graphite is inferior to that of rubber. Tighten the injection port nut securely. Ensure that the graphite O-ring is the correct size for the glass inset.
Fig. 12.3.4 Attaching graphite and fluoride rubber O-ring
O-ring
For splitless/WBI analysis For split analysis
12 Injection Port 12.3 Removing and inserting the glass insert
Q Inserting the glass insert
Insert the glass insert according to the following procedure after attaching the fluoride rubber O-ring or graphite O-ring.
(1) Insert the glass insert into the injection port.
(2) Move the septum nut back over the glass insert and slowly tighten the glass insert nut by hand at first, then 1/3~1/2 turn with wrench.
Fig. 12.3.5
NOTE The position of the injection port components is shown below.
Fig. 12.3.6
Injection port Septum nut
Glass insert nut
Front Right Injection port Stopper Septum nut Purge Carrier Split
12 Injection Port
12.3 Removing and inserting the glass insert
Q If the glass insert breaks in the injection port
If the glass insert breaks in the injection port, take out the thermal insulation cup and the capillary adapter from within the oven and carefully remove the broken glass.
Fig. 12.3.7
NOTE Re-install the capillary adapter without allowing leaks.
If glass chips, etc. are present on the seal face, the seal may be damaged and leaks can occur.
Q Checking for injection port leaks
Leaks can negatively impact reproducibility of results, and can waste carreier gas.
NOTE Septum purge leaks do not affect performance. These error messages canbe cleaned.
(As for the following procedure, there could be cases in which the error message “purge leaks” etc. appears. However, it does not matter to the test. Then select “Reset Error”.)
Check for leaks according to the following procedure.
(1) Turn off the system, and then turn on the system pressing “-” key and “0” key. (2) Press [Start GC] (PF menu) from the [SYSTEM] key screen.
(3) Set the “Flow Control” to “Cont” from the [SYSTEM] key screen. (4) Press [Stop GC] (PF menu) to stop the system temperature control.
(5) User the [MONIT] key to veryfy that the oven, injection portk and detector temperatures have dropped below 40°C.
(6) Press [Off] on the [FLOW] screen to stop AFC control. Carrier gas flow stops. Set the purge flow tate to 0 ml/min.
(7) Remove the capillary column, and seal the connections with a new graphite ferrule (with wire) and column nut.
(8) Install a blank nut (G-type) on both the split vent and purge vent.
Capillary adapter Injection port
Thermal insulation cup Sealing
surface
Oven interior
12 Injection Port 12.3 Removing and inserting the glass insert
(12) Wait five minutes. Confirm that the inlet pressure is 125 and 175 kPa.
If the inlet pressure is above 175 kPa, loosen the column nut slightly to reduce the pres- sure.
If the inlet pressure is below 125 kPa, increase the pressure from the gas cylinder slightly.
(13) Verify that the total flow is less than 2 ml/min. If the flow is above 2 ml/min, a leak exists. (14) Press [On/Off] (PF menu) on the [FLOW] key screen to stop AFC control.
(15) In case of fluoride rubber O-ring, verify that the pressures does not drop more than 215 kPa in one hour or 2.5 kPa in 10 minutes.
In case of graphite O-ring, verify that the pressure does not drop more than 21 kPa in one hour or 3.5 kPa in 10 minutes.
If it does, a leak exists.
(16) If there are no leaks, restore the connections and operational status of the GC-2010.
Q Resolving leaks
If the leak test procedure reveals the presence of an injection port leak, use the following procedure to resolve the problem.
Use Snoop or a similar leak detection fluid to check the column connection for leaks. Tighten the connections at the septum nut, injection port nut, split and purge vents (if the blank nuts are inplace for the leak test), and gas supply tubing.
NOTE Take precautions when using Snoop or similar soap solution not to drip onto electronic parts or wiring.
This could cause an electric shock. In some sensitive analyses, Snoop can interfere with proper detec- tion. In those situations, use an electronic leak detector.
If a leak is found, replace the offending part.
Leaking part Replacement
Near septum nut Replace septum
Around injection port nut Replace glass insert O-ring
At column connection Replace graphite ferrule and column nut
At split or purge vent (during leak test) Replace blank nut
CAUTION
Do not use the leak detecting fluid nor soapy water for gas leak check on the connections above the carrier and detector gas controllers (AFC/APC).