Asterisk problems in Empower report method filters

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In trying to filter standard injections and multiple diluent peaks out of a peak table, a user included:
Sample Type   Unknown
Label                =U*
Name               !=Dil*
as filter elements. No results seen.
Individually, each line works if alone. As soon as there are 2 lines and an asterisk, table is blank.

Work around:
Sample Type         Unknown
Component Type  !=Main Component 
Component Type  !=Diluent Peak
Component Type  !=Specified Impurity
SampleName        <R

Works like a champ.
The !=Main Component and !=Specified Impurities are to keep the API and process impurities out of the total degradants.
The <R thing gets me the unknowns that aren't sample solvent or resolution solution injections, so it serves the same purpose as a U* would (if a U* played well with other filter criteria).

Anyone have an explanation as to why an occasional asterisk acts like a grenade whenever it feels a little crowded?

Answers

  • Ive seen this a few times when making report methods and its usually a conflict between the filter by conditions i.e something that may be ok alone but when combined with another condition, wont make sense.
    In your 1st example is it possible that you had U* labelled samples that didnt contain a diluent peak? Thus by asking Empower to exclude a peak called Diluent in samples which didnt contain it, the table is invalid and didnt populate. Generally the fewer conditions the better. I tend to use Peak Label in the PM to filter rather than putting an asterix because people may spell, for example, Aspirin differently but a peak label of A is hard to get wrong. Then the condition is Peak Label not equal A so no asterixes required. Or in your example put a peak label of A B and C on the peaks you dont want then 1 2 3 on the ones you do and filter by Peak Label between 1 and 3.