Simultaneous determination of 4-substituted cathinones (4-MMC, 4-MEC and 4-FMC) in human urine by HPLC-DAD.

This study developed a selective and rapid high-performance liquid chromatography-diode array detection method for the confirmation of different cathinone derivates in human urine. Samples were prepared by solid-phase extraction (SPE) using procaine hydrochloride as the internal standard. The chromatographic separation was performed on a Kinetex PFP column using isocratic elution.

Detection of tinuvin 770, a light stabilizer of plastic materials from dialysis membranes, by high-performance liquid chromatographic analysis.

Tinuvin 770 [bis(2,2,6,6-tetramethyl-4-piperidinyl)sebacate] is a pharmacologically active agent used worldwide as a light stabilizer for plastic materials. In vitro studies show that it is an L-type Ca(2+) channel and neuronal nicotic acethylcholine receptor blocker. Hypotension, vegetative dysfunction, and neurological symptoms are frequently observed during a haemodialysis treatment.