Simultaneous preconcentration and determination of trace flavonoids in complex matrix by phosphatidylcholine supramolecular solvent-based dispersive liquid-phase microextraction

Abstract

A new phosphatidylcholine supramolecular solvent dispersive liquid-phase microextraction (PCSS-DLPME) combined with high-performance liquid chromatography was first developed and introduced for simultaneous preconcentration and determination of the trace flavonoids (myricetin, quercetin, isorhamnetin, baicalein, wogonin, kaempferide) in Ginkgobiloba, Platycladus orientalis and Scutellaria. In this study, a supramolecular solvent formed by self- assembly of an amphoteric biosurfactant phosphatidylcholine and chloroform was used as the extraction phase in DLPME, and the six flavonoids were extracted from herbal aqueous samples into the supramolecular solvent. The crucial parameters affecting the enrichment factors of target analytes, such as type of organic solvent in PCSS, phosphatidylcholine content in PCSS, type of dispersant, pH of sample phase, concentration of salt, volume of PCSS, shaking time, centrifugation rate and time were investigated and optimized. Under the optimum conditions, the analytes’ EFs were between 107.6 and 205.3, better linearities (r ≥ 0.9927) were obtained, the limits of detection were 0.15–0.5 ng/mL, satisfactory precisions (relative standard deviation were 1.7–11.2%) and average recoveries (87.6%–104.4%) were achieved. This method has the advantages of simple and convenient preparation of supramolecular solvent, high enrichment, good sensitivity and selectivity for flavonoids, which was suitable for the analysis of trace substances in complex matrix.