Longer MassLynx acquisitions do not go to full run time specified - WKB16938

SYMPTOMS

• System acquires data but on chromatogram the data stops part way through the specified time
• Some functions acquire for longer than others, and the lock mas function may acquire data for the full time

• May have recently increased acquisition run times in both the LC and MS methods
• There's plenty of space on the hard drive
• No adverse events are found in the OS event log or the ACQUITY service profile

ENVIRONMENT

• Xevo QTof
  • All  MassLynx SCNs
• Xevo G2 QTof
  • All SCNs including MassLynx 4.1 SCN 802 and SCN 833 and MassLynx 4.2 SCN 990
• SYNAPT
  • All MassLynx SCNs
• SYNAPT G2
  • All MassLynx SCNs
• QTof Premier
  • All MassLynx SCNs

CAUSE

One or more files in the acquired .raw folder has reached the 4 GB limit. Typically this will be the data (.dat) files (e.g., _Func001.dat).

This is a software limitation. The MassLynx SCNs for the affected instruments were written using 32-bit architecture and are restricted to using a Fat32 file structure that limits the amount of data that can be written to any one file to a maximum of 4 GB. 

FIX or WORKAROUND

The only workaround is to avoid hitting this 4 GB limit by reducing the amount of data being generated from any given injection. Recommendations include:

1. Acquire in centroid if possible (this is not applicable to Proteomics data).

2. Try acquiring over a smaller mass range.

3. Try diluting the sample.

5. Limit the retention time range.

ADDITIONAL INFORMATION