Selective extraction of alkaloids in human urine by on-line single drop microextraction coupled with sweeping micellar electrokinetic chromatography.

摘要: Abstract A novel method of on-line single drop microextraction (SDME) coupled with sweeping micellar electrokinetic chromatography (MEKC) for the selective extraction and dual preconcentration alkaloids was developed. In this technique, analytes three were firstly extracted from 4.0 mL basic aqueous sample solution (donor phase, 500 mM NaOH) into a layer n -octanol at temperature 30 °C stirring rate 1150 rpm, then back-extracted acidified acceptor (acceptor 50 mM H 3 PO 4 ) suspended tip capillary 650 rpm. Then, introduced by hydrodynamic injection height difference 15 cm between inlet outlet 300 s, analyzed directly MEKC. With SDME, we able to extract without any interfering components in human urine samples. Under optimum conditions, proposed achieved limits detections (LOD) 0.2 ng mL −1 1.5 ng mL 1583–3556-fold increases detection sensitivity analytes, which indicated that it promising analysis urine.