If you run a Horiba Aqualog, EEMs and absorbance spectra are stored in a proprietary Origin project file (.opj, or .ogw from SampleQ runs). The software lets you export *.dat files. Especially if some pre-processing has happened, this can lead to confusion. For example, have IFEs been corrected already? Maybe a student exported these data ages ago and now nobody can remember. Or maybe you forgot to export data for each opj file and now you have 20 opjs to open individually for the ASCII export dialog.

We had so much data to go through that we decided to automate the data import into the drEEM toolbox completely. All while producing FAIR NetCDF files with the raw data that could be reanalyzed in years to come.

To do all of that, I write “aqualog2nc”, a free, open-source tool that reads OPJ and OGW files directly and exports everything — EEMs, absorbance spectra, blanks, correction vectors, sample metadata — into a single, standards-compliant NetCDF file.

The best part: If this sounds complicated, you don’t even need to touch it yourself. drEEM calls the tool natively through the new importaqualog function. Point it at a folder of Aqualog project files, and importaqualog fetches the right aqualog2nc binary for your platform (macOS, Windows, or Linux) behind the scenes, runs the conversion, and hands you back a fully formed drEEM dataset — samples and blanks matched, ready for PARAFAC — or the raw imported data if you’d rather work with that directly. No more popup status GUIs either; The tool grabs the raw data and reprocesses it into fully corrected EEMs. That’s why it know about the status (and doesn’t need to ask!).

aqualog2nc is open source at github.com/urbanwuensch/aqualog2nc and archived on Zenodo for citation. But if you’re a drEEM user, the easiest way to use it is the one you already have installed: drEEMtoolbox.importaqualog()