Ezchrom Calculation help

[ydna6969]

Hi ,

Wondered if anybody could help.

calculation requires to sum 2 areas and then use standard response factors to calculate % LC.

Uisng the intelligent report I have this calculating response factors for each of the peaks, but not the sum.

Any ideas

THanks

[varossf]

?????
If you can calculate it for the individual peak (area/compound amount) the you can also do it for the sum (area sum/compound amount sum)
Else you must send me the report or better explain it to me

[ydna6969]

Hi

I have summarised peak 1 with RF values and %RSD

I have done the same with peak 2

Then used variable option to average % rsd

Ideally I wanted to sum peak 1 and 2 , RF then take % rsd of this sum figure ,, but not sure it is possible

Thanks

[varossf]

Aha, i think you should use a different table layout then and use the Peak Result table, filter for those 2 compounds you want to report and add the statistics to the column.

[ydna6969]

Hi ,

This is what I require

Peak 1 Peak 2 Sum peak Rf (sum area/conc)
50000 50000 100000 10.1
45000 45000 90000 9.9
55000 50000 105000 10.5
% RSD 3.0

[ydna6969]

HI ,

Sorry , table not in correct format ,

but get the idea.

Problem is how to sum peak areas within one table .

I know this can be done to summarise all table (stat summary)

[varossf]

We have to do this in a matrix. There are some matrix building blocks and I get the idea.

[ydna6969]

Hi ,

I have tried using matrix tables but these cause more harm than good.

The filtering is an expression and doesn't seem to have much use

[varossf]

ydna, i had no time yet to think about it. in advanced reporting it is easy to do, but now in intelligent reporting…..
let me talk to the gurus in Waldbronn on this.

[ydna6969]

Hi ,

Well currently have summarised the % RSD of each peak into 2 separate tables .

Then using report variable option of RSD for each peak taken the average of these 2 rsd's .

Not statistically correct but I have played around with numbers and to 1dp no difference to :

sum areas (A+B) - response factor - % RSD

[varossf]

one of the other suggestions i got if you put them in a group the group will do the calculation for you...

[ydna6969]

Hi ,

hmm,, had a go of grouping but with no real success.

It will group the 2 peaks by name yes,, but dose not sum areas for each injection then calc RF then % RSD
I am not sure what expression to put in for the grouping.. anything I try displays ' statistics no available '

I am thinking if its worth the bother ,, where is certain other CDS's when you need them !