| Device |
Metric |
Description |
| File-system |
RAW file created |
Indication that a measurement is pending. At this stage all components can start recording telemetry data to capture the initialization phase as well. |
|
No data appended to the RAW file |
When the end of the measurement has not been triggered and no data has been written to the file for 30 minutes a possible failure in the data acquisition software has occurred. |
|
No new RAW file created |
When the system is idle and no new RAW file has been created a possible failure in the data acquisition software has occurred. |
| Video |
Droplet formation |
When droplet formation is detected during a normal measurement, possible degradation in the performance of the chromatography has occurred. |
|
Irregularities on the column |
Irregularities (e.g. a hair sticking to the column) on the column tip can interfere with the ionization process and need to be removed. |
|
Distance to the inlet |
The distance to the heated capillary is required to be within the interval of 1mm to 10mm for optimal ionization efficiency. |
| easy.nLC |
Pressure too high |
When the pressure exceeds the allowed maximum, the nLC system shuts down operation and stops the pumps. |
|
Pressure too low |
When the pressure drops below the allowed threshold, there is likely a leak (e.g. in the liquid junction). |
|
Leak in rotor seal A/B or one of the fittings |
When a leak is present in the system one of the pumps will experience heavy and sustained backflow. When this occurs no stable chromatography can be achieved. |
|
Idle bleed setting incorrect |
The idle-bleed is the percent of buffer B to the column when the instrument is idle. A high percentage will result in incorrect results during the loading phase. |
|
Pump syringe empty |
For long gradients the pump syringe can run out of buffer and will need to be refilled before chromatography can be continued. This will however result in irreproducible retention time shifts. |
|
Pressure too low |
The pressure on the pumps has dropped too far for stable chromatography. This can also be indicative of a leak in the t-piece connection to the column. |
| Column oven |
Temperature drop / increase |
The column oven is required to produce a stable temperature environment to produce high quality chromatography. When the temperature deviates more than 0.5°C a possible failure in the column oven has occurred. |
|
Overpressure prevention |
When the LC pumps are near to their maximum pressure, the temperature of the column oven can be increased to decrease the pressure on the pumps. |
| Xcalibur |
MS2 ion inject times |
The MS2 ion inject times are tracked for a user definable history of RAW files. It is the responsibility of the operator to verify whether these have increased above the limit for the samples currently being measured. |
|
Machine dependent parameters |
A number of machine dependent parameters are monitored (e.g. for the LTQ Orbitrap Velos the 'gate lens' is monitored, which is known to degrade to incorrect values, affecting performance of the machine). |
|
Lock mass accuracy |
User definable lock-masses are tracked over the RAW file history. When the accuracy exceeds 15 parts-per-million the mass accuracy has drifted to unacceptable deviations. |
|
FT temperature / pressure |
When the temperature and pressure of the FT system fluctuate or are outside of their expected values. |
