This experiment is based on the LC-MS measurement of photodegradation of benzisothiazolinone, which is a biocide molecule. The photolysis of the compound was studied under irradiation using a UV lamp (254 nm) and samples were taken before the irradiation (t0) and 30, 60 respectively 120 minutes after irradiation. The analysis was performed on the same mass spectrometer as the acetamiprid data but coupled to liquid chromatography, instead of direct infusion. In the dataset, the parent compound, Benzisothiazolinone, is observed at m/z 152.01 and retention time 7.9 minutes as [MH]+. During the irradiation this compound undergoes isomerization, and we obtain a second peak in the chromatogram, with the same m/z value and retention time at 9.5 minutes. Three isomer photoproducts with m/z 168.01 can be observed at retention times 1.2, 5.4 and 8.3 minutes.

1 Run the demo

Select the demo benzisothiazolinone (.mzxml format)

The objective of this study is to see how some peaks of the spectrum evolve over time at different retention times. The peaks (i.e.ย the m/z values at different retention times) associated with a significant change are represented. Here, the color represents the part of variance explained by the model

Explore the plotted data by enabling the data cursor mode

Then, select a pixel (i.e a \(m/z\) and a retention time) to plot the fitted model