When Gas Leaks Cannot Be Stopped

Cause Solution
Part is incorrectly installed. Install part correctly.
Graphite ferrule or other seal such as O-ring is damaged. ・Replace O-ring.
・Additionally tighten the graphite ferrule. If there is leakage even after additional tightening, replace it.
Tubing including pipes and joints is damaged. Replacement of the tubing part is required. Turn off the main power of the instrument, stop gas supply, and contact your Shimadzu sales/service representative.

Carrier gas leak check (Capillary)

Gas leak causes poor repeatability. It also wastes the carrier gas. Check that there is no carrier gas leak.

Step 1

Prepare the instrument.

  1. Press HOME button - [GC Start/Stop Sequence] to display [GC Stop Sequence] screen.
  2. Set [Flow Control] at [On].
  3. Press [Stop GC].
  1. Press HOME button - [GC Start/Stop Sequence] to display [GC Start Sequence] screen.
  2. Set [Start Temp/Det] at [Disable].
  3. Press [Start GC].

Step 2

Press [Monitor].
Monitor screen appears.

Step 3

Wait until the temperatures of the injection port and the detector drops below 50 °C.

Step 4

Ensure that the column oven temperature drops below 40 °C.

Step 5

Press the icon of the Injection port.
[INJ/FLOW] screen appears.

Step 6

Turn [Off] the flow controller control.

Step 7

Set [Purge Flow] at "0" mL/min.

Step 8

Open the column oven door and remove the column on the inlet side.

Step 9

Seal the connection of the column in the injection port.

Step 10

Install a blank nut (G-type (P/N: S221-35566-92)) and a column gasket (P/N: S201-35184) on the purge vent. For SPL or PTV, install a blank nut also on the split vent.

Step 11

Ensure that actual value of [Carrier Gas Primary Pressure] is above "300 kPa".

Step 12

Set parameters at the following values.
Injection Mode : Split
Control Mode : Press
Inlet Press : 150 kPa
Total Flow : 100 mL/min

Step 13

Turn [On] the flow controller control.

Step 14

Wait for [Inlet Press] to rise to 150 kPa or higher, and then turn the control for the flow controller to [Off].

Step 15

Record actual value of [Inlet Press].

Step 16

Wait about 10 minutes and check the decrease of the value. Compare it with actual value of the inlet pressure recorded in step 15.
The followings indicate the presence of a leak.

Actual value of [Inlet Press] in step 15 Leak judgment
Below 150 kPa The decrease is more than 2.5 kPa
150 kPa to 450 kPa The decrease is more than 5.0 kPa
450 kPa to 600 kPa The decrease is more than 7.5 kPa
600 kPa to 750 kPa The decrease is more than 10.0 kPa
Above 750 kPa The decrease is more than 12.5 kPa

Step 17

If gas leak is found, resolve it.

Step 18

Return the connection and settings to original state.
Set [Start Temp/Det] on [GC Start Sequence] screen at [Enable] to start temperature control after you return the settings.

Carrier gas leak check (Packed)

Gas leak causes poor repeatability. It also wastes the carrier gas. Check that there is no carrier gas leak.

Step 1

Prepare the instrument.

  1. Press HOME button - [GC Start/Stop Sequence] to display [GC Stop Sequence] screen.
  2. Set [Flow Control] at [On].
  3. Press [Stop GC].
  1. Press HOME button - [GC Start/Stop Sequence] to display [GC Start Sequence] screen.
  2. Set [Start Temp/Det] at [Disable].
  3. Press [Start GC].

Step 2

Press [Monitor].
Monitor screen appears.

Step 3

Wait until the temperatures of the injection port and the detector drops below 50 °C.

Step 4

Ensure that the column oven temperature drops below 40 °C.

Step 5

Press the icon of the Injection port.
[INJ/FLOW] screen appears.

Step 6

Turn [Off] the flow controller control.

Step 7

Open the column oven door and remove the column on the inlet side.

Note

When removing the column, pull the adapter straight down to avoid breaking the tip of the glass insert.

Step 8

Seal the connection of the column in the injection port.

Step 9

Set [Column Flow] at "100" mL/min.

Step 10

Turn [On] the flow controller control.

Step 11

Wait for [Inlet Press] to rise to 150 kPa or higher, and then turn the control for the flow controller to [Off].

Step 12

Record actual value of [Inlet Press].

Step 13

Wait about 10 minutes and check the decrease of the value. Compare it with actual value of the inlet pressure recorded in step 12.
The followings indicate the presence of a leak.

Actual value of [Inlet Press] in step 12 Leak judgment
Below 150 kPa The decrease is more than 2.5 kPa
150 kPa to 450 kPa The decrease is more than 5.0 kPa
450 kPa to 600 kPa The decrease is more than 7.5 kPa
600 kPa to 750 kPa The decrease is more than 10.0 kPa
Above 750 kPa The decrease is more than 12.5 kPa

Step 14

If gas leak is found, resolve it.

Step 15

Return the connection and settings to original state.
Set [Start Temp/Det] on [GC Start Sequence] screen at [Enable] to start temperature control after you return the settings.

Solutions for gas leaks

Check whether the following parts have gas leaks using leak detector or Snoop.

Take precautions when using Snoop or similar soap solution not to drip onto electronic parts or wiring.
This may cause electric shock.

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).
The drips may damage the controller.

If the leak position is found, perform the following actions.

Item Corrective action
Septum Replace the septum.
Around the injection port Replace O-ring of the glass insert.
Split vent Replace the seal of blank nut.
Purge vent Replace blank nut.
Column connection Replace ferrule, column nut, or ClickTek connector (optional).
Note

  • In some sensitive analyses, Snoop can interfere with proper detection. In those situations, use a leak detector.

  • The instrument allows 0.2 mL/min leakage from split/purge vent.