Commands and Tips for Third-Party Devices
CTC Analytics PAL Samplers: Tips for Injection

CTC PAL samplers support the following injection modes:

PAL Sampler for LC:

Standard HPLC injections -- LC_Inject injection mode (see  PGM File for LC_Inject Mode)

User-defined HPLC injections -- Custom injection mode (see  PGM File for Custom Inject Mode)

PAL Sampler for GC:

Standard GC injections -- GC_Inject injection mode

Headspace injections -- HS_Single and HS_Progr injection modes (see  PGM File for HS_Progr Inject Mode)

The table below indicates which parameters must be defined for each injection mode.

 

Step

 

Parameters for LC_Inject
 

Parameters for GC_Inject
 

Parameters for HS_Single and HS_Progr headspace Modes

1. Preparation

 

 

IncubationTime or IncubStartTime/IncubOffset,

GCCycleTime

2. Load

AirVolume

FillSpeed

FillStrokes

PullupDelay

AirVolume

FillVolume

FillSpeed

PullupDelay

FillStrokes

AirVolume = 0

FillSpeed

PullupDelay

FillStrokes

3. Injection

PreInjDelay

PostInjDelay

InjSpeed

Injector

PreInjDelay

PostInjDelay

InjSpeed

Injector

PreInjDelay

PostInjDelay

InjSpeed

Injector

 

When performing an inject command, the LC PAL sampler performs the following steps:

  1. The sample needle is moved to the specified vial (in the tray or agitator).

  2. The specified sample volume is drawn into the syringe.

  3. Optional: If the AirVolume parameter is set to a value > 0, air is drawn from outside the vial.

  4. The sample needle is moved to the specified injector.

  5. The sampler waits for the Inject Sync signal. (The Inject Sync signal is a PAL synchronization signal.) Set this signal to immediately if no waiting time is required. Alternatively, you can set the signal to the input port of the PAL if the sampler is to wait for a signal from the pump. (For information about the settings, refer to Installing and Controlling Third-Party Devices  CTC Analytics PAL LC/GC Samplers: Installation in the Administrator Help section.)

  6. The needle is moved into the injector.

  7. The sampler pauses for the time specified by PreInjDelay.

  8. The injection valve is moved into the Load position (LC_Inject mode only).

  9. The content of the syringe is dispensed into the sample loop or the GC inlet.

  10. The sampler pauses for the time specified by PostInjDelay.

  11. The injection valve is moved into the Inject position (LC_Inject mode only).

  12. The needle is moved out of the injector.

  13. The needle returns to the Home position.

 

 Tip: 

Steps 4 and 5 are omitted in the GC injection mode. Additional steps are required for headspace injections (refer to  Tips for Headspace Operation).