User guide

316 Advanced User Guide
10 Detectors
uECD gas flows
uECD linearity
The uECD response factor versus concentration curve is linear
for four orders of magnitude or more (linear dynamic range =
10
4
or higher) for a broad range of compounds. You should still
run a calibration curve on your samples to find the limits of the
linear range for your materials.
uECD detector gas
The uECD operates with either nitrogen or argon/methane as
the makeup and anode gas. Purity is critical; gases must exceed
99.9995% purity.
Because of the high detector sensitivity, carrier and makeup gas
must be dry and oxygen- free. Moisture, chemical, and oxygen
traps in good condition should be installed in carrier and
makeup gas supply lines. Do not use plastic (including Teflon)
tubing, plastic- bodied traps, or O- ring seals.
uECD temperature
To prevent peak tailing and to keep the cell clean, the detector
temperature should be set higher than the highest oven
temperature used—the setpoint should be based on the elution
PS = Pressure Sensor
PS
Valve
Frit
Restrictor
Restrictor
EPC Module
Anode purge and makeup gas
Vent
63
Ni
Column
Capillary adapter