AccQ Tag Ultra / ACQUITY UPLC H-Class: What to check if Arg and Gly are not resolved? - WKB206494

SYMPTOMS

• Arg (arginine) and Gly (glycine) are not resolved

ENVIRONMENT

• AccQ•Tag Ultra
• ACQUITY UPLC H-Class

CAUSE

High concentration of standard/wrong preparation of mobile phase

FIX or WORKAROUND

1. Dilute the standard 10 times using the method described in the H-Class Amino Acid Analysis System Guide, page 4-3.
2. Prepare the mobile phase used for each mobile phase line using the method described in H-Class Amino Acid Analysis System Guide, pages 3-5 and 3-6.

ADDITIONAL INFORMATION

Check the following

- Chromatogram acquired from the standard measurement (one on a scale that shows the absorbance of AMQ (the large peak that firstly elutes) and one on a scale that shows the resolution of amino acids)
- Instrument method report
- Sample queue screen when running the sample set (in order to check the injection amount, method set name, column equilibration pre-run, number of blank injections, etc.)
- Preparation of the mobile phase used for each mobile phase line (whether or not the method described in P3-5 to 6 of the H-Class Amino Acid Analysis System Guide is followed)
- Preparation of the standard (whether the 10-fold dilution is performed as described in the method from H-Class Amino Acid Analysis System Guide P4-3)