Data reduction is pretty straightforward. The two things you’re mostly checking for are a) retention time and b) qualifier ions. If the retention time and qualifier ions match, it’s likely a hit. If you’re not sure, just leave it in and the reviewers will tell you if you need to delete the compound from the data. It seems weird at first, but the more you do it the easier it gets. Data reduction is more difficult with highly saturated and matrix samples because they likely require manual integration.

Manual Integration

Manual integration is done when compound peaks aren’t being identified properly. The integration might have the wrong baseline, retention time, or peak cutoff. When manually integrating, you need to print out the graphics report before and after fixing the integration.

To manually integrate a peak (while in QEdit Quant Result):

1. Go to QEdit > Graphics Report to Printer for the compound before you manually integrate the peak.
2. Zoom into the peak to see it better, then hold down the right-click button on the mouse and drag it. This sets the new baseline for integration. Try to make sure the baseline is straight.
3. Go to QEdit > Graphics Report to Printer for the compound after you manually integrate the peak. Make sure you can see the peak fully when you print the graphics report.
4. Stamp the manually integrated graphics report. Check the reason for manual integration and initial with the date.

Compounds that usually require manual integration in dirty samples (like 90% of the time it’s at least one of these):

• vinyl chloride
• 1,1-dichloroethene
• cis-1,2-dichloroethene
• benzene
• trichloroethene
• toluene
• ethylbenzene
• m,p-xylene
• o-xylene
• isopropylbenzene
• n-propylbenzene
• 1,3,5-trimethylbenzene
• 1,2,4-trimethylbenzene
• p-isopropyltoluene

Non-integrated peaks

Some peaks are so saturated that they don’t get integrated at all when the data is initially calculated. Other times, the peak is next to an extremely saturated peak so the program fails to recognize the peak is there. Check the second page of the raw data to see if there are any extremely large unidentified peaks. Do a TIC search to identify the compound. To do so:

1. Right-click on the unknown peak. It should pull up a spectra for the specific scan.
2. Right-click on the spectra. This should generate a screen showing compound identification.

• If the compound is in the compound list, manually integrate the peak.
• If the compound is not in the compound list, print the identification for that compound (we call this a TIC).

Generating TIC file

Some folders ask for a TIC along with the data to identify compounds that aren’t part of the method. To generate a TIC report for data, you first need to set the minimum area counts for the TIC. This is determined by calculating 10% of the corrected area of the peak with the closest retention time to the 3rd IS in the instrument blank for that day. Print out the LSC summary for the blank (Library > LSC Summary to Printer). Print this out first.

You don’t need to do anything before printing this since we only need it for the corrected area value. The corrected area changes every day. You need to redo this for every day you run samples requiring TIC.

[insert highlighted pic of value]

This value should be inputted into the integration parameters file being used for the LSC report. To check which file is being used, go to Library > Edit Parameters for LSC Report > RTEINT Parameter File and write down/memorize the integration parameters file name. Then, go to Integrate > Integration Parameters and load the parameter file being used for the LSC report. Under minimum peak area input the corrected area value you calculated from the instrument blank. Save and return to the original integration parameters file (RTE.p).

[insert picture of screen]

Now, you can generate the LSC detailed report for the instrument blank and all samples (Library > LSC Detailed to Printer). Make sure you also generate the RR file to include the LSC report (Tools > Generate RR File > Current Results and LSC’s) for all samples you report.

The generated RR file should either be in the data folder or in the RR file itself. It’ll look like one of these.

[RR file in data folder]

[LSC report appended to bottom of RR file]