Firstly, general conditions for the ion source and ion transmission parameters were studied. To this aim, a solventbased standard at 250 μg L−1 was injected into the system, in positive and negative mode, and different parameters of the source and the analyser (scan time, inter-scan time and collision energy of the acquisition functions of LE and HE employed in the MSE mode) were optimised in order to improve absolute sensitivity of the characteristic ions, observing that the conditions indicated in the previous section provided suitable results.