How to perform high-mass calibration with the Xevo G2-XS under waters_connect - WKB249329

OBJECTIVE or GOAL

Calibrate the Xevo G2-XS for mass range 5000 and 8000 as part of instrument setup for high-mass acquisitions.

ENVIRONMENT

• Xevo G2-XS
• waters_connect 3.0
• Xevo G2-XS Driver 4.1

PROCEDURE

1. Perform the instrument setup for mass range 1200 and 2000 using 0.5 mM sodium formate (in 90% 2-propanol/10% water) on sample fluidics vial C as well as 50 pg/µL LeuEnk and 100 fmol/µL GluFib (in 50% water/50% acetonitrile/0.1% formic acid) on reference fluidics vial B.
   This is required because it includes the ADC setup and detector setup.
2. Remove the sodium formate from vial C and the fluidics (e.g., with 70% water/30% methanol).
3. Attach 2 µg/µL sodium iodide (in 50% water/50% 2-propanol) to MS-fluidics vial C.
4. In the system console, under Xevo G2-XS > Setup > Instrument Setup, enable the High Mass Calibration sliders and click Start. Continue calibration.
   Note: If you click Start, the system assumes you attached the sodium iodide solution. Click continue to start the calibration.
   
   

ADDITIONAL INFORMATION

For high-mass acquisitions, the automatic lockspray option in the methods uses [Glu1]-Fibrinopeptide B as lock mass. It is essential to provide GluFib in the lock mass solution because only a 10 Da mass window around GluFib is acquired in the data.

Always wash the fluidics when changing between sodium iodide and sodium formate. The high concentrated sodium iodide can easily contaminate the sodium formate and make it unusable.

2 µg/µL sodium formate can cause sodium adducts. Avoid loading this solution into the reference syringe, and minimize the time this solution is infused.
If disturbing sodium adducts are seen after calibration, flush the ESI source with LC flow for about two hours.

When sodium iodide ages and oxidizes over time, the high-mass peaks disappear and the solution requires exchange.
The high concentration of 2 µg/µL is used to ensure sufficient intensity of the high-mass peaks over time.
In order to minimize the effect of sodium adducts, the 2-µg/µL sodium iodide solution can be diluted (e.g., 1:50 to obtain 40 ng/µl Sodium Iodide) in 50% water/50% 2-propanol for use on a daily basis.