Definition
The molecular mass calculated for the expected compound from reference data, on a stated basis, usually the free base rather than the salt. It is a property of the molecule named at scope review, not a measurement, and it is the value any mass result would be compared against.
The theoretical mass depends on the salt form and counter-ion basis chosen. A comparison against the wrong basis produces an apparent mismatch that is a bookkeeping error, not a product problem.
Related terms
About mass spectrometry
Terms a reader meets on mass-spectrometric reports from other laboratories, and on confirmatory work sent out. This laboratory has no in-house mass spectrometer, and its certificates carry no mass spectrum.
Electrospray ionisationMass-to-charge ratioCharge stateDeconvolutionMass accuracyIsotope patternIon suppressionIsobaricStereoisomerRetro-inverso peptide