Adduct error means m/z is wrong when peptide result is imported from a scientific library into a Tof 2D method - WKB54773

SYMPTOMS

• When a peptide is exported from results of a peptide mapping analysis to the scientific library and then imported to a Tof 2D method, the adduct used to calculate the expected m/z is wrong
• Export a peptide ID to Scientific Library:
• Expected m/z shown in library:
• Create 2D Tof method:

• When the Scientific Library entry is imported into the method, the expected m/z is wrong.

• Component masses calculated in the Manage Components section of Analysis Method > Purpose do not match the theoretical masses in the UNIFI Mass Calculator

ENVIRONMENT

• UNIFI 1.9 SR4
• UNIFI 1.9 SR3

CAUSE

Bug

(It seems the H+ mass is added twice before the neutral mass is divided by the charge to generate the m/z.

FIX or WORKAROUND

Create custom 2+ and 3+ (and other) adducts and manually select them in the adducts column of the "Specific Mass Chromatogram(s)" pane. This forces the method generator to redo the m/z calculation and get it right.

ADDITIONAL INFORMATION

Raised as fault INFULA-812.

According to the fault record, this problem is fixed in UNIFI 1.9.9 and later and did not occur in UNIFI 1.8.2.