Chromatography Forum

Hi. Im having some trouble here trying to determine the signal to noise in an analysis I've done with a Shimadzu instrument using the software LC solution. The version seem to be 1.2 from what i can tell, and I can't seem to find any function to calculate the S/N directly in the software. If anyone knows about any such function, it would be very appreciated.

Also, if there is no such function I would have to do this manually and Im just wondering, how much would the calculation differ if you compare a software calculate S/N versus a manually calculated S/N?

Thanks!
/Pär

this won't help much, but it has to be said: if you calculate S/N in exactly the same way as the software, you should get the same answer, but there are unfortunately many different ways to calculate S/N, and frequently the way it's done by software isn't clear. For example, Thermo's Xcalibur has three different integrators, two of which return S/N ratios for peaks, but the actual ratios returned for the same peak in the same chromatogram vary about 10-fold as I remember (and this is in one package from one manufacturer!). So my answer to your second question is that it is unlikely you will get the same answer manually as you would by software, but equally unlikely that two software packages will give the same answer.

Hi Pär

thing is there is more than one way of calculating S/N ratio, so you first need to chose if using the EP pharmacopiea formula and reccomendations, in shor 2*H/h where h is meqasured over a minimum time depending of width at hal peak hight in a standard, or something else.

generally speaking if software spits out the correct values, manual or system calcutated ration should not differ significantly (number of decimal places used-set in reports may cause a small difference).

hmm considering your first name, Swedish by any chance?

Okay, thanks people. Too bad the software doesn't seem to have this function.
Yes krickos, I'm Swedish. Born and raised in Östersund. How about you?

Okay, thanks people. Too bad the software doesn't seem to have this function.
Yes krickos, I'm Swedish. Born and raised in Östersund. How about you?

Hi
I guess you have tried to talk to a Shimadzu rep in Sweden?

Personally I live in Stockholm area.

No, but the boss at my company since he provides demos for shimadzu salesmen. But the problem was solved. We had a newer software, Lab solution, which had that function and made the evaluation much easier

Krickos: Forgot to mention that I live and work in Uppsala, after studying in Linköping and working in Växjö.