| Berberine, jatrorrhizine, palmatine are major isoquinoline alkaloids in Rhizoma Coptidis and have variety of pharmacological effects, including anti-inflammatory, anticancer, anti-oxidative, anti-diabetic and so on. Single and compound preparations are widely used in clinical. Therefore, to build some simple, reliable and sensitve methods for the determination of three alkaloids have important clinical significance. Sample pretreatment plays a vital role in sample analysis. The aims to convert analytes to a more suitably detectable form, includes interferent removal and analytes preconcentration. Traditional liquid-liquid extraction is time-consuming and usually requires some toxic volatile organic solvents that have adverse effects on the operators and environment. Rapid, efficient, organic solvent-free and environmental friendly sample preparation becomes the focus of analytical chemistry. In this paper, several pretreatment methods based on high performance liquid chromatography to determine berberine, jatrorrhizine and palmatine in biological samples were studied. The main research contents are as follows:Part1Determination of alkaloids in urine by temperature-controlled ionic liquid dispersive liquid-liquid microextraction coupled with HPLCA simple, senstitve and environmental friendly method based on temperature-controlled ionic liquid dispersive liquid-liquid microextraction (TCIL-DLLME) combined with high performance liquid chromatography-diode array detection (HPLC-DAD) was developed for preconcentration and determination of berberine, jatrorrhizine and palmatine in human urine samples. The proposed method used1-butyl-3-methylimidazolium hexafluorophosphate ([C4mim][PF6]) as the extraction solvent. The ionic liquid was dispersed completely into the sample solution under the drive of temperature and need not to use organic solvent as dispersive solvent. Under the optimized conditions, good linear relationships were observed in the concentration range from2-200ng/mL for the three alkaloids, with the correlation coefficients (r2) more than0.9986. The detection limits based on the signal to noise (S/N) ratio of3were in the range of0.83～1.25ng/mL. The enrichment factors were between118and135. The spiked recovery of urine samples for each analyte was in the range of92.6%～105.8%.Part2Vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction based on solidification of floating organic droplet method for determination of alkaloids in human plasmaA new vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction based on solidification of floating organic droplet method was adopted to extract three alkaloids in human plasma samples. In this method, a solvent of lower density than water and a proper melting point, n-octanoic acid, was employed as extraction solvent, and non-ionic surfactant Tergitol TMN-6which had no ultraviolet absorption was used as emulsifier to facilitate the dispersion of extraction solvent in the aqueous samples. After extraction assisted by vortex agitation, the two phases can be separated by centrifugation, then the floated extractant was solidified in ice bath and was easily collected for analysis. Under optimal conditions, good linear relationships were observed in the concentration range of5～500ng/mL for three alkaloids, with the correlation coefficients (r2) more than0.9997. The detection limits (LODs) were in the range of0.24～0.60ng/mL. The enrichment factors were between40and45. Good recovery results (84.6%～96.6%) were obtained when the proposed method was applied to determine these three alkaloids in human plasma samples.Part3Extraction and determination of alkaloids in urine using an aqueous two-phase system of hydrophilic ionic liquid and salt with HPLCAqueous two-phase system (ATPS) consisting of a hydrophilic ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate,[C4mim][BF4]) and ammonium sulfate ((NH4)2SO4) coupled with high performance liquid chromatography-diode array detection (HPLC-DAD), was developed for the simultaneous separation, enrichment and determination of three alkaloids in human urine samples. The important parameters affecting the extraction efficiency such as ionic liquid volume, the amount of salt and sample pH were optimized by response surface methodology (RSM). The optimal experimental conditions obtained from this statistical evaluation included:0.53mL [C4mim][BF4],0.93g (NH4)2SO4and pH5.29. Under the optimized conditions, good linear relationships were observed in the concentration range from2.5to500ng mL-1 for three alkaloids, with the correlation coefficients (r2) more than0.9997. The detection limits based on the signal to noise (S/N) ratio of3were in the range of0.56～0.85ng mL-1. The enrichment factors were between20and25. Good recovery results (91.8%～109.6%) were obtained when the proposed method was applied to determine these three alkaloids in human urine samples. |
PDF Full Text Request