Effervescent-salt-assisted dispersive micro-solid-phase extraction using mesoporous hybrid materials coupled with ultra-performance liquid chromatography for the determination of trace-level compounds in complicated plant preparations.

A novel effervescent-salt-assisted dispersive micro-solid-phase extraction using mesoporous hybrid materials was developed for the extraction of minute traces of constituents in complicated plant preparations. In this study, a special tablet containing carbon dioxide sources (sodium dihydrogenphosphate and sodium carbonate) and the sorbent (mesoporous hybrid materials) was prepared. The effects of different parameters influencing the extraction efficiency such as the concentration of salts, the type and concentration of mesoporous material, pH of diluent, and desorption solvents were investigated and optimized. Results show that the proposed method using green solvents (water) as extraction solutions required low consumption of sample amount and obtained high enrichment efficiency. Moreover, under optimized conditions, the tested tanshinones exhibited good linearity (r(2) > 0.994) in the concentration range of 0.5 to 80 ng mL(-1). The limits of detection values were lower than 0.0803 pg using UV-visible detection. The developed method was successfully applied for the analysis of trace tanshinones in compound Danshen dripping pill and Danqi tablet samples.

Ionic-liquid-micelle-functionalized mesoporous Fe3O4 microspheres for ultraperformance liquid chromatography determination of anthraquinones in dietary supplements.

A magnetic solid-phase extraction method using ionic liquid (IL)-micelle-functionalized mesoporous Fe3O4 microspheres (MFMs) was proposed for the preconcentration of anthraquinones in dietary supplements. The analytes were then determined by ultraperformance liquid chromatography combined with an ultraviolet detector. The extraction parameters, such as the choice of ILs, the concentrations of ILs and MFMs, the pH of diluent, and the concentration of acetic acid in the eluent, were presented. Under the optimized conditions, the limits of detection and limits of quantitation were 0.4-2.8 ng mL(-1) and 1.4-9.4 ng mL(-1), respectively. The accuracy of the proposed method was investigated by recovery in herb and granules of Radix et Rhizoma Rhei, yielding values between 89.25% and 96.48%. The use of the proposed method in the sample pretreatment of complex dietary supplements is feasible due to the high surface area and excellent adsorption capacity of MFMs after modification with IL.

Highly sensitive analysis of flavonoids by zwitterionic microemulsion electrokinetic chromatography coupled with light-emitting diode-induced fluorescence detection.

A rapid zwitterionic microemulsion electrokinetic chromatography (ZI-MEEKC) approach coupled with light-emitting-diode-induced fluorescence (LED-IF, 480nm) detection was proposed for the analysis of flavonoids. In the optimization process, we systematically investigated the separation conditions, including the surfactants, cosurfactants, pH, buffers and fluorescence parameters. It was found that the baseline separation of the seven flavonoids was obtained in less than 5min with a running buffer consisting of 92.9% (v/v) 5mM sodium borate, 0.6% (w/v) ZI surfactant, 0.5% (w/v) ethyl acetate and 6.0% (w/v) 1-butanol. High sensitivity was obtained by the application of LED-IF detection. The limits of detection for seven flavonoids were in the range of 3.30×10(-8) to 2.15×10(-6)molL(-1) without derivatization. Ultimately, the detection method was successfully applied to the analysis of flavonoids in hawthorn plant and food products with satisfactory results.

Ionic liquid-based one-step micellar extraction of multiclass polar compounds from hawthorn fruits by ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry.

An ionic liquid (IL)-based one-step micellar extraction procedure was developed for the extraction of multiclass polar analytes (protocatechuic acid, chlorogenic acid, epicatechin, hyperoside, isoquercitrin, quercetin) from hawthorn fruits and their determination using ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UHPLC-Q-TOF/MS). Compared to conventional organic solvent extractions, this newly proposed method was much easier, more sensitive, environmentally friendly, and effective as well. Several important parameters influencing the micellar extraction efficiency are discussed, such as selection of ILs, surfactant concentration, and extraction time. Under the optimal conditions, good linearity was achieved for each analyte with correlation coefficients (r(2)) ranging from 0.9934 to 0.9999, and the recovery values ranged from 89.3 to 106% with relative standard deviations lower than 5.5%. Results suggest that the IL-based one-step micellar extraction could be an alternative and promising means in future food analysis.