# Bracket Standard Recovery Custom Field

in Informatics

hello,

I'm trying to figure out a way to calculate the bracket standard recovery using a custom field? i.e, the % difference of the bracket standard injections compared to the previous standard (bracket) injections.

I'm trying to figure out a way to calculate the bracket standard recovery using a custom field? i.e, the % difference of the bracket standard injections compared to the previous standard (bracket) injections.

0

## Answers

Cant you use a report for this? Label your standards as sequential eg S1 S2 S3...Sn etc, Then create peak tables which calculate the %RSD between labels S1 and S2 then S3 and S4 etc? You can use Data Filtering Conditions in the peak table of the report method to do this.

% bracket recovery =[|A-B| x 2/ (A+B)] x 100

Where A: Mean area response of standard prior to the sample loop

B: Mean area response of standard after the sample loop

Currently we use excel to calculate this , but we are trying to get away from the use of excel sheets (for data integrity purposes). I don't believe the report can do this , it would need to be a custom field from what I see

Adding an ABS will allow for any negative values. This should work if you label all your standards as A and B so A----samples----B then another set of A......samples....B etc. Because of all or nothing, your % bracket std recovery should only generate a result for all the B standards, where all arguments are present. So at each B injection, your value for Recovery_Brkt_Stds will calculate using the current B and the previous A injections, then this repeats again for the next set. But this assumes you are using a Sliding No Overlap method of standards injections where you quantitate your samples off A and B, clear calibration then start again with a new A and B. If not this wont work. Also, there is every chance there is an easier way to do this, im just going by what I see and I haven't access to a test project, so good luck.