Nanofibrous Online Solid-Phase Extraction Coupled with Liquid Chromatography for the Determination of Neonicotinoid Pesticides in River Waters.

Polymeric nano- and microfibers were tested as potential sorbents for the extraction of five neonicotinoids from natural waters. Nanofibrous mats were prepared from polycaprolactone, polyvinylidene fluoride, polystyrene, polyamide 6, polyacrylonitrile, and polyimide, as well as microfibers of polyethylene, a polycaprolactone nano- and microfiber conjugate, and polycaprolactone microfibers combined with polyvinylidene fluoride nanofibers. Polyimide nanofibers were selected as the most suitable sorbent for these analytes and the matrix.

3D-Printed Magnetic Stirring Cages for Semidispersive Extraction of Bisphenols from Water Using Polymer Micro- and Nanofibers.

A magnetic stirring device allowing semidispersive solid phase extraction of eight bisphenols (A, AF, AP, C, BP, G, M, and Z) from river waters using polymer nano- and microfibers followed by HPLC with spectrophotometric detection has been developed and applied. About 50 mg of fibers was placed in a round, cage-like housing consisting of two identical 3D printed pieces that were locked together by a magnetic stirring bar. Magnetic stirring action of the cage devices enabled highly efficient interaction of the fibers housed inside with the aqueous samples and analyte transfer without risking fiber compaction and/or damaging.

Screening of extraction properties of nanofibers in a sequential injection analysis system using a 3D printed device.

A novel application of the three-dimensional printing technology for the automation of solid phase extraction procedures in a low-pressure sequential injection analysis system is presented. A 3D printed device was used as a housing for nanofiber membranes in solid phase extraction. The applicability of the device is demonstrated with the extraction of substances of various physical-chemical properties.

Direct-immersion single-drop microextraction and in-drop stirring microextraction for the determination of nanomolar concentrations of lead using automated Lab-In-Syringe technique.

Two operational modes for Lab-In-Syringe automation of direct-immersion single-drop microextraction have been developed and critically compared using lead in drinking water as the model analyte. Dithizone was used in the presence of masking additives as a sensitive chromogenic complexing reagent. The analytical procedure was carried out inside the void of an automatic syringe pump.

Flow-batch analysis of clenbuterol based on analyte extraction on molecularly imprinted polymers coupled to an in-system chromogenic reaction. Application to human urine and milk substitute samples.

A fully automated spectrophotometric method based on flow-batch analysis has been developed for the determination of clenbuterol including an on-line solid phase extraction using a molecularly imprinted polymer (MIP) as the sorbent. The molecularly imprinted solid phase extraction (MISPE) procedure allowed analyte extraction from complex matrices at low concentration levels and with high selectivity towards the analyte. The MISPE procedure was performed using a commercial MIP cartridge that was introduced into a guard column holder and integrated in the analyzer system.