Using VUVision Software to identify mis-identified peaks
In Part 1, we looked at a gasoline sample with a mis-identified peak. We could see that the measured absorbance spectrum and the fit spectrum weren’t matching up well, and the residuals indicated a bad fit. So, what’s the next step?
The first thing we can do is try and identify the compound using VUVision™ Software. The full VUV reference library contains thousands of spectra, while the VUV PIONA spectral library only contains compounds that are pertinent to gasoline. If we load the file into VUVision and take a look at the peak, we see in Figure 1 that the compound is N-methylaniline (NMA), a compound that’s been reported as a harmful gasoline additive. Although NMA can boost a fuel’s octane rating, it has been demonstrated to cause high gum formation, lower gasoline stability, and lead to oil leaks by swelling seal rings.
Now that we’ve identified the compound, we can use VUVision’s Library Editor tool to copy N-methylaniline over to the PIONA library. Once the sample is re-run, we can see that the peak is properly identified, as shown in Figure 2.
Now, VUV Analyze can identify and quantify NMA. We can tell VUV Analyze to report NMA in each sample by adjusting the report method, shown below in Figure 3. In Part 3, we’ll take the principle of customizing your analysis with VUV Analyze and apply it to QA/QC standard checks.