Liquid-phase microextraction combined with high-performance liquid chromatography for the enantioselective analysis of mefloquine in plasma samples

Three-phase, liquid-phase microextraction combined with high performance liquid chromatography-fluorescence detection for the simultaneous determination of fluoxetine and norfluoxetine in human plasma

“…A clear decline in analyte extraction was observed with salt addition. A similar negative effect was reported by some authors when using LPME for the extraction of drugs from plasma [30,32]. Most likely, a high salt concentration modifies the physical properties of the diffusion film and reduces the rate of diffusion of analytes into the organic solvent [44].…”

“…All LPME experiments were performed using Accurel Q3/2 polypropylene hollow fibre membranes (600 m I.D., 200 m wall thickness and 0.2 m pore size) from Membrana (Wuppertal, Germany). These were in a "U" format, as described previously [25,32,33]. The hollow fibre was manually cut to 7 cm and employed for LPME.…”

“…In three-phase mode, analyte extraction occurs using three liquid phases, including: (1) the sample solution (donor phase), where pH is adjusted to keep compounds neutrally charged, (2) the organic extractor phase, which is immobilised in fibre pores, and (3) the receiving aqueous phase (acceptor phase), with a pH that is adjusted to ionise the analytes. Compounds in their non-ionised form are extracted into the organic solvent and are subsequently back-extracted into the acceptor phase, which can be directly analysed via HPLC [30][31][32].…”

Hollow-Fiber Liquid-Phase Microextraction and Chiral LC–MS/MS Analysis of Venlafaxine and its Metabolites in Plasma

“…In other studies employing HF LPME, similar recoveries were observed to those reported here. De Santana et al [19] and Magalhães et al [21] demonstrated recoveries between 24 and 35% for the extraction of mirtazapine and mefloquine from plasma samples, respectively. The recovery rates for rosiglitazone and its metabolites obtained in microsomal preparation were 47-70% [20].…”

“…The addition of salt to the samples can increase analyte recovery in microextraction processes due to the salting-out effect [20,21]. However, higher salt concentrations in the donor phase can result in the increase of sample viscosity, which had a negative effect on the extraction.…”