Can any experts out there tell me how to obtain S/N ratios on the peaks after an injection? I am new to method development and am using Agilent 1100 w/Chemstation. Thanks in advance.

How about start by reading the software manuals. There are multiple ways to report both noise and s/n with ChemStation. It doesn't take an expert - it requires literacy.

Thank you for your great advice. However, I do not find the manual anywhere. May be the person left the job took it with him.

If you don't want to help that's ok, but please don't assume that people have all the resources that you have. Mr. Literacy.

Dear Ye of Few Resources

You do know, of course, that all of the user manuals are available from the Agilent website, free of charge.

Hey you know what, Mr/Mrs/Ms literacy know everything: Just talked to Agilent, they can't figure it out either. It's not a function in the original Chemstation software. Now I have to try a macro program in order to get what I want (may or may not happen). So I think it's already installed in your units that you just take it for granted.

I think you may want to go back to school and READ someting about the software before you put your comment out. This will only make yourself even more embrassing.

You have a really big mouth and very little else where it counts.

Dear Dumb Dumbs

Right from the Agilent website (just like I said)

Enabling Calculation And Reporting Of Signal-To-Noise Ratios- CE/GC/LC/A to D ChemStation

The lack of quality Agilent service/support never fails to amaze me.

Could we please keep this place civil? Snide comments are not necessary, but if you insist on them please have the guts to identify yourself.

I'm not impressed by either of you.

Chris

I think anon#2 is mean and arrogant. Anon#1 started out with a simple question politely. He's new so I think we should help him out.

Go to data analysis screen, pull down Report and select Specify report. In the style section, select Performance+noise and OK.

Then pull down Report again and select System Suitability, select Edit noise ranges. Enter your time range and OK.

Make sure you change these parameters before your run. It doesn't work on existing data that were acquired prior to the change.

For details you can go to Agilent website look for A10197.doc. Good luck.

Also, Agilent's right about the macro. You can also install macro#11 in the software CD. The path is LC_ucl\macros. In addition, it has a lot more to offer than just the s/n ratio. Instructions are in the readme.txt

By the way, I have the guts to id myself, how about you guys?

Gen,
Thanks for the correct info and getting out of the bickering. I am an Agilent Applications person and all that you said is exactly correct. I couldn't have stated it better. Anon#1 if you have any problems please call you local Agilent rep and we can get you any more info or even email you the usermanuals.

Hi!
What Gen wrote is correct. But need a small modification with respect to one of his/her views that the parameters for determining the S/N ratio have to be put before acquiring the data. This is indeed not the case. You can determine the S/N ratio of any data without fixing these parameter before acquiring the run.
When you process the data after fixing the noise range, you will obtain noise in term of ASTM,POP and 6*SD mode. You can use help of chemstation to understand the difference in these values and how they are calculate. Depending on your own use you can choose one of the mode to determine the S/N ratio. I think this should solve your problem.

Hi Noname,
Get the sensitivity of your method by diluting a sample until you know at what concentration you can not detect it. Divide that amount into your requirement for the low range of your analyte.
This number will be the best work you can ever do, if you have a blank matrix, work around the sensitivity you found until you get the value for a barely detectable amount in the matrix. Calculate the S/N from it.
Jim