IMM Instrument Guides
IMM Instrument Guides
Most common “advanced” issue with the ISQ-Mercator is clogging of the instrument. As clogging leads to increased pressure, the clogged piece can be identified easily by disecting the instrument, if reference pressures are known.
All pressures were recorded on a (reasonably) cleaned instrument with flow of 0.6 ml/min and 5% ACN : 95% H2O mobile phase after pressure stabilized.
Point of disconnection |
Pressure (bar) |
|---|---|
Full system |
222-223 |
At the ISQ entrance (at the ISQ 3-way valve) |
212-213 |
After the UV-VIS cell (excl. UV-VIS→ISQ tubing) |
200-201 |
After the column (excl. Column→UV-VIS tubing) |
196-198 |
Between column and pre-column |
20-21 |
Before the pre-column (incl. Sampler→Column tubing) |
3 |
note1: Incl. means that the part was left in the system, giving additional backpressure note2: ISQ needle itself gave only ~3 bars of backpressure with the abovementoned conditions
From the abovementioned table, specific pressure for each instrument part at the abovementioned conditions can be derived:
Part |
Pressure (bar) |
|---|---|
Pumps, autosampler, tubing to columns |
3 |
Pre-column |
17-18 |
Column |
176-178 |
UV-VIS cell + Column→UV-VIS tubing |
3-4 |
UV-VIS→ISQ tubing (redtube) |
11-12 |
ISQ (incl. 3-way valve) |
10 |