Determination of ivermectin and transformation products in environmental waters using hollow fibre-supported liquid membrane extraction and liquid chromatography-mass spectrometry/mass spectrometry

A simple and easy-to-use extraction method for aqueous samples based on hollow fibre-supported liquid membrane (HF-SLM) followed by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) was developed to determine ivermectin and transformation products, the monosaccharide (TP1) and the aglycon of ivermectin (TP2). The proposed method attained enrichment factors up to 80, after optimising parameters, such as fibre length, organic solvent, stirring speed, salt level, pH in samples/fibre, extraction time and fibre emptying technique. Method validation with tap and lake water samples provided good linearity and detection limits of 0.2, 1.6 and 0.9 mu g/l for ivermectin, TP1 and TP2 in lake water with RSD below 15%