Liquid-phase Microextraction - High Performance Liquid Chromatography In The Analysis Of Traditional Chinese Medicine

Objective Single-drop liquid-phase microextraction(SD-LPME)coupled with high performance liquid chromatography(HPLC)was developed for the determination of rutin in Sophora japonica L.and capsula preparation.Method A self-made LPME system was adopted.The optimal experimental conditions,100μl n-butanol as organic solvent,3.00 ml 0.01 mol/L HCl as the donor aqueous solution,600 r/min of the stirring rate,and 10 min of the extraction time,were selected.After extraction,the extractant was dissolved in 100μl methanol.An aliquot(20μl)was injected into an HPLC system with methanol:1%HAc(50∶50)as the mobile phase.The C₁₈column was used with flow rate at 0.8 ml/min and temperature at 30℃.The detective wave length was set at 257 nm.Under the optimal conditions high extract efficiency was obtained.Result The linear range of rutin is from 10 to 100μg/ml with the correlation coefficient(r) 0.9925.The average relative recoveries of rutin in Sophora japonica L.and capsula were (101.7±5.5)%(n=9)and(103.4±3.3)%(n=9)respectively.The relative standard deviation was lower than 8.5%.The limit of detection was 1.0μg/ml for rutin.Conclusion This method was applied to eliminate the interference of matrices,and to decrease the volume of use of organic solvent,and results showed the possibility for the determination of rutin in Sophora japonica L.and capsula preparation.It is a quick,efficient and sensitive pre-processing technique. Objective Liquid-phase microextraction with back extraction(LPME/BE)based on porous hollow fibres coupled with high performance liquid chromatography(HPLC)was developed for the simultaneous determination of oxymatrine and matrine in Sophora flavescens Ait.,injection preparation and biological matrices.Method The effects of kinds of hollow fiber and microextraction solvent,pH in the donor and acceptor phases,stirring rate and extraction time on the extract efficiency were investigated.The optimal experimental conditions,the polyacrylonitrile fiber was cut into 10 cm pieces,ispropyl alcohol as organic solvent,2.00 ml pH9 NaOH as the donor phase,pH4 HCl as the acceptor phase,1500 r/min of the stirring rate,and 30 min of the extraction time,were selected.An aliquot(20μl),after extraction,was subsequently withdrawn into a microsyringe and directly injected into an HPLC system with methanol:pH6.0 phosphate buffer(57∶43)as the mobile phase.The C₁₈column was used with flow rate at 0.8 ml/min and temperature at 35℃.The detective wave length was set at 220 nm.Under the optimal conditions high extract efficiency was obtained.Result In Sophora flavescens Ait.and injection preparation:The linear ranges of oxymatrine and matrine were from 11 to 437μg/ml and from 10 to 433μg/ml respectively with the correlation coefficient(r)better than 0.999.The relative standard deviation was lower than 9.4%and 6.7% respectively.The average relative recoveries of oxymatrine and matrine in injection preparation were 83.0%～116.1%and 108.8%～117.8%respectively.The average relative recovery of oxymatrine in Sophora flavescens Ait.was 104.3%～114.7%.The limit of detection was 1.0μg/ml for oxymatrine,1.0μg/ml for matrine.In plasm:The linear ranges of oxymatrine and matrine were from 5 to 119μg/ml and from 3 to 117μg/ml respectively with the correlation coefficient(r)better than 0.997.The relative standard deviation was lower than 5.9%and 5.1%respectively.The average relative recoveries of oxymatrine and matrine were 88.8%～106.4%and 96.0%～104.2%respectively.The limit of detection was 1.4μg/ml for oxymatrine,1.0μg/ml for matrine.In liver:The linear range of matrine was from 3 to 131μg/ml with the correlation coefficient(r)0.9995.The relative standard deviation was lower than 6.8%.The average relative recovery of matrine was 93.7%～101.6%.The limit of detection was 1.0μg/ml for matrine. Conclusion This method applied to eliminate the interference of matrices,had improved the selectivities,and results showed the possibility for the simultaneous determination of oxymatrine and matrine in Sophora flavescens Ait.,injection preparation and biological matrices. Objective Nonaqueous liquid-phase microextraction with back extraction(NLPME/BE)based on porous hollow fibres coupled with high performance liquid chromatography(HPLC)was developed for the simultaneous determination of quercetin,kaempferol and isorhamnetin in Ginkgo Biolbal..Method The effects of kinds of hollow fiber and microextraction solvent,pH in the donor and acceptor phases,stirring rate and extraction time on the extract efficiency were investigated.The optimal experimental conditions,the polysulfone fiber was cut into 10 cm pieces,octanol as organic solvent,pH10 NaOH as acceptor phase,10^-3mol/L HCI of methanol 2.00 ml as the donor phase,1500 r/min of the stirring rate and 30 min of the extraction time,were selected.An aliquot(20μl),after extraction,was subsequently withdrawn into a mierosyringe and directly injected into an HPLC system with methanol:0.4%H₃PO₄(60∶40)as the mobile phase.The C₁₈ column was used with flow rate at 0.8 ml/min and temperature at 30℃.The detective wave length was set at 360 nm.Under the optimal conditions high extract efficiency was obtained.Result The linear ranges of quercetin,kaempferol and isorhamnetin were from 3.63 to 49.36μg/ml,from 3.63 to 49.36μg/ml and from 1.85 to 25.19μg/ml respectively,with the correlation coefficient(r)better than 0.994.The average relative recoveries were(95.6±4.8)%(n=5), (107.5±5.3)%(n=5)and(103.4±4.1)%(n=5)respectively.The relative standard deviation was 4.6%,3.7%and 4.3%respectively.The limit of detection was 40,70 and 90ng/ml respectively.Conclusion Nonaqueous liquid-phase microextraction was adopted for the first time.This method was applied to simultaneous determination of quercetin,kaempferol and isorhamnetin in Ginkgo Biolbal..