[loosescrews]

To some extent. There are limitations on the technique, including, but not limited to, not determining the relative concentrations and not detecting all components. The WSJ article actually links to an older Wired article about doing gas chromatography and mass spectroscopy on WD-40 and the results: https://www.wired.com/2009/04/st-whatsinside-6/

[hurricanepootis]

You could use techniques like HPLC to determine the concentrations within the sample if you know what's in it.