Simple way to use average standard area in CF with single point curve

bryanpais

Hey everybody,

It's my first time posting here. I'm sure others have done this and that it has been discussed at some point, but I came up with a super simple way to use average standard area in a custom field without using summary functions like S.%..AVE(Area) or applying numerous corrections to something like the "amount" field.

My company typically calculates the percent of analyte present in blank injections as:

Percent analyte in blank = (Peak area, blank/Average peak area, standard)*100

Typically the blank is just solvent with no dilution factor, while I make heavy use of dilution factors with other injections. I could have used a percent assay CF (Amount*100), but would have had to correct for standard concentration and standard DF. Fields like "value" don't carry over to non-standard injections, and I couldn't use "entered X value", which also doesn't carry over to unknown injections, without correction. Instead, I realized the following is true for single point calibration curves for the fields "B" and "vt":

B*vt = Average standard area

I created the following CF:

(Area/(B*vt))*100

It works perfectly! Since there is no summary function or label reference, it also displays the result prior to processing, assuming the standard injections are integrated/calibrated prior to integrating/quantitating the injections of interest. This also applies to processing, which is no problem if processing sample sets by label reference.

I know this isn't a groundbreaking calculation or anything, but it could see it being useful, especially when allowing users to see the result of a custom field prior to processing is desirable. Hopefully this helps somebody else!