The presence of Polysorbate 80 in samples can challenge liquid chromatography-electrospray ionisation mass spectrometry (LC-ESI-MS) analysis as it is easily ionised and detected. In this study, we demonstrate that interference from Polysorbate 80 can be reduced by complexation with a metal ion followed by precipitation by thiocyanate. The precipitation procedure was tested on a mixture of low molecular weight compounds (e.g. amino acids and non-amino organic acids) and it was shown that none of the tested compounds were precipitated.