Chromatography Forum

On Agilent ChemStation, A.09 with GC-FID (6890), we routinely use the data system to give automated system suitability reports for peak areas; this works great for most of our test methods (which are external standard).

For the few we use that are internal standard methods, we use the Area of the Analyte Peak divided by the Peak Area of the Internal Standard Peak for each injection, then tally that ratio and calculate the %RSD of those ratios. The problem is that we are currently entering in the peak areas into Excel manually, and using Excel to calculate the RSD for us. Is there a way in ChemStation to to %RSD like I want, even a user Macro, available. I'm about average on a computer, so I'd need pretty specific directions. Thanks.

Or maybe someone likes writing Macros for "fun" and would like a challenge. A decade ago we paid Agilent to help write a macro for FAME assay by GC where we then could have the data station calculate equivalent weight of the blend, etc., and that works fine (even though I never could've done that on my own, even in a decade)...

For myself, I am not too familiar with ISTD calculations.
However, I do see a chance of at least extracting your peaks with the areas to an Excel file _automatically_ . If you see this as an improvement, I could try. Please contact me at kawieroe (at) gmx.de

I have not done any internal standard calculations in ChemStation, but my understanding is:
1) Define your internal standard in the calibration table (there is a column labelled ISTD).
2) Where you specify the reporting options, in the Qunatitative results section (top right) change Calculate: to ISTD.

The ChemStation help options should be able to fill in any missing details.

I have not done any internal standard calculations in ChemStation, but my understanding is:
1) Define your internal standard in the calibration table (there is a column labelled ISTD).
2) Where you specify the reporting options, in the Quantitative results section (top right) change Calculate: to ISTD.

The ChemStation help options should be able to fill in any missing details.

1) Define your internal standard in the calibration table (there is a column labelled ISTD). I already do this.
2) Where you specify the reporting options, in the Quantitative results section (top right) change Calculate: to ISTD. We use ISTD% now, I'll look into this.

With all these macros options I have really considered take a class to learn more about it.

Something that you can do fairly easily which would remove your manual data entry step would be to generate a .xls file from Chemstation (not sure your exact version, but should be something like 'Generate Detailed File' as a quant report that spits out a detail.xls file or something similar) and then use an Excel spreadsheet that links to the detail.xls file. Then instead of plugging in your values by hand you can just change the link to the data file.

It's not as elegant as a macro, but it will save you some time and is a pretty simple thing to do. Plus if you get in the habit of exporting your data to Excel for manipulation it's a lot easier to find folks experienced in Excel or Access than in Chemstation macros (I'd think).

I've done in the past to export results to Excel. That may help "a little", but that really isn't what I'm looking for. I would think that the software designers would've included this.

Have you tried using the ConCal pulldown and evaluating samples as a CCV? I believe it has a %Dev column which may be what you're looking for.

Is this the LC or GC or GC-MS ChemStation?

For the LC/GC version, I can send you a macro that will export the data to Excel after each run. It is not difficult to use.

You can also generate a Batch Report and save it as an Excel file.

There are several ways to do this, but as someone else mentioned, getting a little training would help a great deal. You might find that there are several other features that you could use. Like many software programs, ChemStation is easy to use but not intuitive to learn.

seriously, get the training! We did, one day on-site, tailored to our requirements. We've never regretted it. It is possible to spend a lot of time setting up macros to do what Chemstation already has, except that the function we're looking for is well hidden behind some strange button...

lmh:
Who did your training? Where are you located? It is always good to know about these options. I am sure the rest of the readers could benefit.

Create a calibration table using internal standard. Put the amount of internal standard to 1 and say yes for internal standard in box on extreme right.Then in the calibration settings select the ISTD method it will automatically calculate the amounts according to the ISTD

mbicking, our training was from Crawford Scientific, I believe, but was a few years ago now. Back then I believe they were subcontracted training by Agilent within the UK, and they certainly did a very good job. We got on-site training, and they discussed with us beforehand exactly what we needed, and weren't afraid to get involved in pointing out where we needed things we didn't know we needed.

Use a report from chemstore mate. Can be done so easily then and all you would need to do is press print after it has been set up.

As far as macros go, i know nothing about them. Sorry!