Important cleaning notes:

• Frequent cleaning actions and rinsing methods are strongly recommended to minimize the risk of instrument contaminations or performance loss.
• For optimal time-efficiency, clean and rinse the instruments routinely between the kit runs while a new kit is prepared (see recommendations below).
• Monitor test sample intensities each time you run the SST and perform troubleshooting when you observe significant signal decrease. Clean and rinse system again if required.
• Check immediately after each plate run if all injections have worked and if the peaks are visible and have a good shape. In case of missing peaks or bad shapes, troubleshoot and reinject the plate or affected samples.
• The instrument requires a full service at least every 6 months when the kit is used in high throughput.
  • Please be aware that performance-related issues that cannot be resolved by instrument cleaning are not within biocrates’ responsibility and must be handled by the user or the LC-MS engineer!

Cleaning actions after every plate run (LC or FIA):

• Rinse the column for 60 min using wash solvent according to user manual (after LC plate only).
• Install 10% methanol (in water) as mobile phase A and wash solvent as mobile phase B. Rinse entire LC-MS system:
  • 15 min at 100% A offline (to waste, MS switched off)
  • 15 min at 100% B offline (to waste, MS switched off)
  • 15 min at 100% A online (to source/ESI needle, MS switched on)
  • 15 min at 100% B online (to source/ESI needle, MS switched on)
• Keep the wash solvent as mobile phase B, transfer some wash solvent to autosampler vial, and perform 10 blank injections using 100% B.

Before FIA run:

• Install FIA mobile phase for the assay, purge and flush the entire LC-MS system with FIA mobile phase at 1 mL/min until the pressure is stable.
• Perform another 10 blank injections using FIA mobile phase as blank solvent. Perform more blank injections to decrease background noise if necessary. Continue with SST according to user manual.

Before LC run:

• Install mobile phases A and B for the assay, purge and perform another 10 blank injections using 50% methanol as blank solvent.
• Perform more blank injections to decrease background noise if necessary. Continue with SST according to user manual.

After every 2 kits:

• Rinse the autosampler for 20 min with 10% methanol (in water) to get rid of salts, followed by another 20 min with wash solvent to get rid of lipids (in the same way as the entire LC-MS system above)
• Clean Curtain Plate or Cone according to manufacturer’s instructions.
• Wipe the Orifice (without removing the Orifice plate) using a foam rod, first with water, followed by isopropanol and methanol.
• Wipe the tip of the ESI electrode using a foam rod, first with water, followed by isopropanol and methanol.

After every 5 kits or more:

• Replace ESI electrode after every 5 kits.
• Perform instrument front-end cleaning (Orifice and QJet or Q0) after every 15-20 kits.