User guide

86 Advanced User Guide
4 Chromatographic Checkout
To Check uECD Performance
1 Gather the following:
• Evaluation column, HP- 5 30 m × 0.32 mm × 0.25 µm
(19091J- 413)
• uECD performance evaluation (checkout) sample
(18713–60040, Japan: 5183- 0379)
• 4- mL solvent and waste bottles or equivalent for
autoinjector.
• Chromatographic- grade isooctane
• 2- mL sample vials or equivalent for sample.
2 Verify the following:
• Clean fused silica indented mixing liner installed. If not,
install it.
• Chromatographic- grade gases plumbed and configured:
helium for carrier gas, nitrogen for makeup.
• Empty waste vials loaded in sample turret.
• 4- mL vial with diffusion cap filled with hexane and
inserted in Solvent A injector position.
3 Install the evaluation column. (See the procedure for the SS,
PP, COC, MMI, or PTV in the Maintenance manual.)
• Bake out the evaluation column for at least 30 minutes at
180 °C. (See the procedure for the SS, PP, COC, MMI, or
PTV in the Maintenance manual.)
• Be sure to configure the column.
4 Display the signal output to determine baseline output. A
stable baseline output at any value between 0.5 and 1000 Hz
(ChemStation display units) (inclusive) is acceptable.
• If the baseline output is < 0.5 Hz, verify that the
electrometer is on. If the offset is still < 0.5 Hz, your
detector requires service.
• If the baseline output is > 1000 Hz, there may be chemical
contamination contributing to the signal. Bakeout the
uECD. If repeated cleanings do not give an acceptable
signal, check gas purity. Use higher purity gases and/or
install traps.
5 Create or load a method with the parameter values listed in
Table 12.