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1.
An optimized microwave‐assisted extraction (MAE) method and RP‐HPLC method were developed for the simultaneous extraction and determination of rutin, forsythiaside A, and phillyrin in the fruits of Forsythia suspensa. The key parameters of the open‐vessel MAE process were optimized. A mixed solvent of methanol and water (70:30, v/v) was most suitable for the simultaneous extraction of the three components. The sample was soaked for 10 min before extraction. The optimized conditions were: microwave power 400 W, temperature 70°C, solvent‐to‐material ratio 30 mL/g, and extraction time 1 min. Compared to conventional extraction methods, the proposed method can simultaneously extract the three components in high yields and was proved to be a more rapid method with a lower solvent consumption. The optimized HPLC–photodiode array detection analysis was validated to have good linearity, precision, accuracy, and sensitivity. The developed MAE followed by RP‐HPLC is a fast and appropriate method for the simultaneous extraction and determination of rutin, forsythiaside A, and phillyrin in the fruits of F. suspensa.  相似文献   

2.
An optimized microwave‐assisted extraction method using water (MAE‐W) as the extractant and an efficient HPLC analysis method were first developed for the fast extraction and simultaneous determination of D (+)‐(3,4‐dihydroxyphenyl) lactic acid (Dla), salvianolic acid B (SaB), and lithospermic acid (La) in Radix Salviae Miltiorrhizae. The key parameters of MAE‐W were optimized. It was found that the degradation of SaB was inhibited when using the optimized MAE‐W and the stable content of Dla, La, and SaB in danshen was obtained. Furthermore, compared to the conventional extraction methods, the proposed MAE‐W is a more rapid method with higher yield and lower solvent consumption with a reproducibility (RSD <6%). In addition, using water as extractant is safe and helpful for environment protection, which could be referred to as green extraction. The separation and quantitative determination of the three compounds was carried out by a developed reverse‐phase high‐performance liquid chromatographic (RP‐HPLC) method with UV detection. Highly efficient separation was obtained using gradient solvent system. The optimized HPLC analysis method was validated to have specificity, linearity, precision, and accuracy. The results indicated that MAE‐W followed by HPLC–UV determination is an appropriate alternative to previously proposed method for quality control of Radix Salviae Miltiorrhizae.  相似文献   

3.
A novel and reliable method based on microwave‐assisted extraction (MAE) followed by HPLC‐UV was developed and validated for the simultaneous quantification of six pharmacologically important oxoisoaporphine alkaloids in the total plants of Menispermum dauricum DC. The optimal MAE extraction condition was performed at 60°C for 11 min with ethanol–water (70:30, v/v) as the extracting solvent, and the solvent to solid ratio was 20:1. Chromatographic separation was achieved on a reversed‐phase YMC C18 column (250 × 4.6 mm, i.d., 5 µm) with a gradient mobile phase consisting of A (1% aqueous formic acid) and B (acetonitrile containing 1% formic acid) at a flow rate of 1.5 mL/min. The detection wavelength was set at 422 nm. Excellent linearity over the investigated concentration ranges was observed with values of r >0.999 for all analytes. The method developed was validated with acceptable sensitivity, intra‐ and inter‐day precision and extraction recoveries. It was successfully applied to the determination of six alkaloids in Menispermum dauricum DC from different sources and different parts of Menispermum dauricum DC. The results obtained indicated that the method is suitable for the quality control of Menispermum dauricum DC. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

4.
The aim of our study was to increase the extraction efficiency of carvacrol, rosmarinic, oleanolic and ursolic acid from the different species of oregano herbs (Origanum onites L., Origanum vulgare spp. hirtum and Origanum vulgare L.). Various extraction methods (ultrasound-assisted, heat-reflux, continuous stirring, maceration, percolation) and extraction conditions (different solvent, material:solvent ratio, extraction temperature, extraction time) were used, and the active substances were determined by HPLC. The lowest content of carvacrol, rosmarinic, oleanolic and ursolic acid was obtained by percolation. During heat-reflux extraction, the content of active substances depended on the solvent used: ethanol/non-aqueous solvent (glycerol or propylene glycol) mixture was more effective compared with ethanol alone. The results showed that for each species of oregano the most optimal extraction method should be selected to maximize the content of biologically active substances in the extracts.  相似文献   

5.
A method based on microwave‐assisted extraction (MAE) has been developed for the determination of paclitaxel and five related taxoids, namely 10‐deacetylbaccatin III (10‐DAB III), cephalomannine, 10‐deacetylpaclitaxel (10‐DAT), 7‐xyl‐10‐ deacetylpaclitaxel (7‐xyl‐10‐DAT), and 7‐epi‐10‐deacetylpaclitaxel (7‐epi‐10‐DAT) in Taxus species in this study. The influential parameters of the MAE procedure were optimized, and the optimal conditions were as follows: extraction solvent 80% ethanol solution, solid/liquid ratio 1:10 (g/mL), temperature 50°C, and three extraction cycles, each cycle 10 min. The method validation for LC‐MS/MS analysis was performed. The LOD and LOQ were 3.16–9.20 and 12.20–30.45 ng/mL, respectively. Repeatability and reproducibility for the six taxiods with RSD ranged from 2.78 to 3.85% and from 5.26 to 6.60%. The recoveries of the method for the six taxoids were 92.6–105.6%. The developed MAE‐LC‐MS/MS method was also successfully applied to determine the contents of six taxoids in different Taxus species.  相似文献   

6.
The performance of microwave‐assisted extraction and HPLC with photodiode array detection method for determination of six analgesic and anti‐inflammatory drugs from plasma and urine, is described, optimized, and validated. Several parameters affecting the extraction technique were optimized using experimental designs. A four‐factor (temperature, phosphate buffer pH 4.0 volume, extraction solvent volume, and time) hybrid experimental design was used for extraction optimization in plasma, and three‐factor (temperature, extraction solvent volume, and time) Doehlert design was chosen to extraction optimization in urine. The use of desirability functions revealed the optimal extraction conditions as follows: 67°C, 4 mL phosphate buffer pH 4.0, 12 mL of ethyl acetate and 9 min, for plasma and the same volume of buffer and ethyl acetate, 115°C and 4 min for urine. Limits of detection ranged from 4 to 45 ng/mL in plasma and from 8 to 85 ng/mL in urine. The reproducibility evaluated at two concentration levels was less than 6.5% for both specimens. The recoveries were from 89 to 99% for plasma and from 83 to 99% for urine. The proposed method was successfully applied in plasma and urine samples obtained from analgesic users.  相似文献   

7.
A cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) method was established for the determination of oleanolic acid and ursolic acid in cornel. The two components were separated in the running buffer of 40 mmol/L sodium borate containing 5% methanol, 25 mmol/L SDS and 15 mmol/L hydroxypropyl-beta-cyclodextrin (HP-beta-CD). The applied voltage was 24 kV. The wavelength of detection was 200 nm. The temperature was kept at 25 C. Cinnamic acid was used as the internal standard. The analytical performance of the method was tested with respect to linearity, precision and recovery. The calibration curves were linear in the range of 10.15-243.6 microg/mL, r=0.9993 (oleanolic acid) and 10.07-241.7 microg/mL, r=0.9994 (ursolic acid); the intra-day precision (RSD) was less than 3.7% (oleanolic acid) and 4.1% (ursolic acid); the inter-day precision (RSD) was less than 4.2% (oleanolic acid) and 4.9% (ursolic acid). The limits of detection were 1.6 microg/mL for both components. The method proved to be sensitive, rapid, accurate and suitable for the determination of oleanolic acid and ursolic acid in cornel.  相似文献   

8.
《中国化学会会志》2018,65(8):989-994
In this study, an electromembrane extraction (EME) method combined with a simple HPLC‐UV analysis was developed and validated for the determination of valproic acid in human plasma samples. The major parameters influencing EME procedure, namely the solvent composition, voltage, pH of acceptor and donor solutions, salt effect, and time of extraction, were evaluated and optimized. The drug was extracted from the donor aqueous sample solution (pH 5) to the acceptor aqueous solution (pH 13). The donor and acceptor phases were separated by a hollow fiber dipped in 1‐octanol as a supported liquid membrane. A voltage of 60 V during 25 min was applied as the driving force. The drug concentration enrichment factor obtained was >125, which enhanced the sensitivity of the method. The limit of detection and the limit of quantitation were 0.2 and 0.5 μg/mL, respectively. The proposed method was successfully applied to a human plasma sample, with a relative recovery of 75%. The method was linear over the range 0.5–10 μg/mL for valproic acid (R2 > 0.9996) with a repeatability (%RSD) between 0.9 and 3.3% (n = 3). Valproic acid is an anticonvulsant drug with poor UV absorption, and EME can improve the sensitivity of HPLC‐UV for the determination of valproic acid in plasma samples.  相似文献   

9.
A microwave‐assisted extraction (MAE) protocol and an efficient HPLC analysis method were first developed for the fast extraction and simultaneous determination of bisphenol F diglycidyl ether (Novolac glycidyl ether 2‐Ring), Novolac glycidyl ether 3‐Ring, Novolac glycidyl ether 4‐Ring, Novolac glycidyl ether 5‐Ring, Novolac glycidyl ether 6‐Ring, bisphenol A diglycidyl ether, bisphenol A (2,3‐dihydroxypropyl) glycidyl ether, bisphenol A (3‐chloro‐2‐hydroxypropyl) glycidyl ether, bisphenol A bis(3‐chloro‐2‐hydroxypropyl) ether, bisphenol A (3‐chloro‐2‐hydroxypropyl) (2,3‐dihydroxypropyl) ether in canned fish and meat. After being optimized in terms of solvents, microwave power and irradiation time, MAE was selected to carry out the extraction of ten target compounds. Analytes were purified by poly(styrene‐co‐divinylbenzene) SPE columns and determinated by HPLC‐fluorescence detection. LOD varied from 0.79 to 3.77 ng/g for different target compounds based on S/N=3; LOQ were from 2.75 to 10.92 ng/g; the RSD for repeatability were <8.64%. The analytical recoveries ranged from 70.46 to 103.44%. This proposed method was successfully applied to 16 canned fish and meat, and the results acquired were in good accordance with the studies reported. Compared with the conventional liquid–liquid extraction and ultrasonic extraction, the optimized MAE approach gained the higher extraction efficiency (20–50% improved).  相似文献   

10.
The method of capillary zone electrophoresis (CZE) with direct UV detection was developed for the determination of oleanolic acid, ursolic acid, quercetin and apigenin. and then for the first time successfully applied to the analysis of four analytes in Swertia mussotii Franch and its preparations. Various factors affecting the CZE procedure were investigated and optimized, and the optimal conditions were: 50 × 10?3 mol/L borate‐phosphate buffer (pH 9.5) with 5.0 × 10?3 mol/L β‐cyclodextrin, 15 kV separation voltage, 20 °C column temperature, 250 nm detection wavelength and 5 s electrokinetic injection time (voltage 20 psi). Under the conditions, oleanolic acid, ursolic acid, quercetin and apigenin could be determined within the test ranges with a good correlation coefficient (r2 > 0.9991). The limits of detection for conditions, oleanolic acid, ursolic acid, quercetin and apigenin were 0.3415, 0.2003, 0.0062 and 0.2538 µg/mL, respectively, and the intra‐ and inter‐day relative standard deviations were no more than 4.72%. This procedure provided a convenient, sensitive and accurate method for simultaneous determination of oleanolic acid, ursolic acid, quercetin and apigenin in S. mussotii Franch. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

11.
A rapid method combining microwave‐assisted extraction (MAE) and high‐speed counter‐current chromatography (HSCCC) was applied for preparative separation of six bioactive compounds including loganic acid ( I ), isoorientin‐4′‐O‐glucoside ( II ), 6′‐O‐β‐d ‐glucopyranosyl gentiopicroside ( III ), swertiamarin ( IV ), gentiopicroside ( V ), sweroside ( VI ) from traditional Tibetan medicine Gentiana crassicaulis Duthie ex Burk. MAE parameters were predicted by central composite design response surface methodology. That is, 5.0 g dried roots of G. crassicaulis were extracted with 50 mL 57.5% aqueous ethanol under 630 W for 3.39 min. The extract (gentian total glycosides) was separated by HSCCC with n‐butanol/ethyl acetate/methanol/1% acetic acid water (7.5:0.5:0.5:3.5, v/v/v/v) using upper phase mobile in tail‐to‐head elution mode. 16.3, 8.8, 12., 25.1, 40.7, and 21.8 mg of compounds I–VI were obtained with high purities in one run from 500 mg of original sample. The purities and identities of separated components were confirmed using HPLC with photo diode array detection and quadrupole TOF‐MS and NMR spectroscopy. The study reveals that response surface methodology is convenient and highly predictive for optimizing extraction process, MAE coupled with HSCCC could be an expeditious method for extraction and separation of phytochemicals from ethnomedicine.  相似文献   

12.
A simple and green sodium dodecyl sulfate‐synergistic microwave‐assisted extraction method was developed to extract and determine the iridoids, phenylpropanoids, and lignans in Eucommiae Cortex followed by ultra‐high‐performance liquid chromatography with photodiode array detection. The biodegradable solution (sodium dodecyl sulfate) was used as a promising alternative to organic solvents. The response surface methodology provided the optimum extraction conditions (2 mg/mL sodium dodecyl sulfate, 1100 W microwave power, and 6 min extraction time). The recoveries of three types of components ranged from 95.0 to 105% (RSDs < 5%). The intra‐ and inter‐day precision and accuracy were less than 3.40% and within the range of 97.1‐105%, respectively. Compared with other extraction methods, this newly established method was more efficient and environmental friendly. The results demonstrated that sodium dodecyl sulfate‐synergistic microwave‐assisted extraction followed by ultra‐high‐performance liquid chromatography with photodiode array method was applicable for the simultaneous extraction and determination of these three types of compounds for quality evaluation of Eucommiae Cortex.  相似文献   

13.
Microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE) and conventional extraction of vanillin and its quantification by HPLC in pods of Vanilla planifolia is described. A range of nonpolar to polar solvents were used for the extraction of vanillin employing MAE, UAE and conventional methods. Various extraction parameters such as nature of the solvent, solvent volume, time of irradiation, microwave and ultrasound energy inputs were optimized. HPLC was performed on RP ODS column (4.6 mm ID x 250 mm, 5 microm, Waters), a photodiode array detector (Waters 2996) using gradient solvent system of ACN and ortho-phosphoric acid in water (0.001:99.999 v/v) at 25 degrees C. Regression equation revealed a linear relationship (r2 > 0.9998) between the mass of vanillin injected and the peak areas. The detection limit (S/N = 3) and limit of quantification (S/N = 10) were 0.65 and 1.2 microg/g, respectively. Recovery was achieved in the range 98.5-99.6% for vanillin. Maximum yield of vanilla extract (29.81, 29.068 and 14.31% by conventional extraction, MAE and UAE, respectively) was found in a mixture of ethanol/water (40:60 v/v). Dehydrated ethanolic extract showed the highest amount of vanillin (1.8, 1.25 and 0.99% by MAE, conventional extraction and UAE, respectively).  相似文献   

14.
In this research, a novel homogeneous liquid‐phase microextraction method was successfully developed based on applying octanoic acid as low‐density extraction solvent. The method was applied for extraction and determination of chlorophenols (CPs) as model compounds. Twelve milliliter of the sample solution was poured into a home‐designed glass vial. Sixty microliter of octanoic acid was solved in water sample by adjusting pH and ionic strength. By rapid addition of 75 μL of concentrated HCl (6 M), a cloudy solution was obtained. Phase separation occurred at 5000 rpm for 5 min. After that, 20 μL of the collected phase (approximately 26 μL) was injected into the HPLC‐UV instrument for analysis. The effect of some parameters such as the volume of concentrated HCl (phase separation reagent), ionic strength, extraction time, centrifugation time, and the volume of extracting phase on the extraction efficiency of the CPs were investigated and optimized. The preconcentration factors in a range of 159–218 were obtained under the optimal conditions. The linear range, detection limits (S/N = 3), and precision (n = 3) were 1– 200, 0.3–0.5 μg/L, and 4.6–5.1%, respectively. Tap water, seawater, and river water samples were successfully analyzed for the existence of CPs using the proposed method and satisfactory results were obtained.  相似文献   

15.
A new method was employed to solid-phase extract ursolic acid from Ilex kudingcha C. J. Tseng using molecularly imprinted microspheres (MIMs) as the sorbent. Using a surface molecular imprinting technique, MIMs for ursolic acid were prepared with bonded beta-CD and acrylamide in combination based on functionalized poly(glycidyl methacrylate) microspheres (F-PGMA). Compared with non-MIMs (NIMs), MIMs showed high adsorption capacity, significant selectivity, and good site accessibility for ursolic acid. The maximum static adsorption capacities of the MIMs and NIMs for ursolic acid were 42.5 and 4.9 micromol/g, respectively. Chromatographic analysis shows that ursolic acid and oleanolic acid could be separated well when MIMs were used as the stationary phase of HPLC. The conditions of molecularly imprinted SPE (MISPE) of ursolic acid from the herb extract were optimized using different concentrations of ethanol solutions as loading, washing, and eluting solutions. The successful extraction of ursolic acid by MIMs provided a possible innovative approach to separate ursolic acid from herb.  相似文献   

16.
Ursolic acid (UA) is the most important bioactive phytoconstituent of Eucalyptus × hybrida Maiden leaves and exhibits anticancer, antimutagenic, anti‐inflammatory, antioxidative, and antiprotozoal activities. In this study, microwave‐assisted extraction technique was employed for rapid isolation of UA from the leaves of Eucalyptus × hybrida and simultaneously HPLC‐diode array method was developed for the quantification of UA. Effects of several experimental parameters on the extraction efficiencies of UA, such as type and volume of extraction solvents, microwave power and extraction time, were evaluated. The optimal extraction conditions were found to be 20 mL of a mixture of chloroform/methanol, 60:40; liquid‐to‐material ratio, 4:1; preleaching time, 10 min; microwave power, 600 W; temperature, 50°C; and microwave irradiation time, 5 min. Under the optimum conditions, the yield of UA was found to be 1.95 ± 0.08% in the dry leaves of Eucalyptus × hybrida. The results showed that microwave‐assisted extraction is a more rapid extraction method with higher yield and lower solvent consumptions than the conventional method. It is a faster, convenient, and appropriate method and it may be used for rapid isolation and quantification of UA and other important phytoconstituents present in the leaves of Eucalyptus × hybrida.  相似文献   

17.
To separate and determine oleanolic acid and ursolic acid, a rapid and accurate HPLC using γ‐CD as the mobile phase additive was developed. The effect of CD nature and concentration, and the acidity of the mobile phase on the chromatographic behavior of two bioactive triterpenes were systematically studied. Two bioactive triterpenes were completely separated (R = 3.11) on a Kromasil® C18 column (150×4.6 mm id, 5 μm) with the mobile phase consisting of acetonitrile/0.1% phosphoric acid with 2 mM γ‐CD as the mobile phase modifier (60:40, v/v). The flow rate was set at 1.0 mL/min and the eluent was detected at 210 nm for two bioactive triterpenes. The linearity of the method was excellent (r=0.9999) over the studied range of 6–300 μg/mL for oleanolic acid, and 12–600 μg/mL for ursolic acid. The LOD and LOQ were 1.5 and 5.0, 1.0 and 3.0 μg/mL for oleanolic acid and ursolic acid, respectively. The optimized method was successfully applied to separate and determine two bioactive triterpenes in five Chinese herbs. It is concluded that this method could be used for rapid and accurate qualitative and quantitative analysis of the two bioactive triterpenes in Chinese herbs.  相似文献   

18.
A simple hollow fiber liquid‐phase microextraction method for the determination of synthetic pyrethroid metabolites, 3‐phenoxybenzoic acid and 4‐hydroxy‐3‐phenoxybenzoic acid, in human and rat urine was developed and validated. A polypropylene hollow fiber tightly fitted onto a Nylon rod and impregnated with organic solvent served as a disposable extraction device. Desorption of analytes was carried out in NaOH solution, analyzed further by gradient HPLC and diode array detection method. Important factors were identified using Taguchi OA16 (45) orthogonal array design and further optimized using univariate approach. The optimum method performance was observed when 1 mL of urine hydrolyzed with 0.2 mL of concentrated HCl was further supplemented with 100 mg of NaCl and extracted for 120 min into dihexyl ether immobilized in the pores of the hollow fiber. Metabolites were desorbed into 0.1 mL of 0.1 M NaOH for another 120 min. Limits of detection and quantitation of 15 and 50 ng/mL were obtained for both analytes. Relative standard deviations of 1.6–12.6% over the linear range (50–10,000 ng/mL, r > 0.9906) were observed. Intra‐ and inter‐day accuracies of the method ranged from 98.3 to 109.5% and from 93.3 to 110.9%, respectively. The optimized method was applied to the analysis of real urine samples collected from rats exposed orally to cypermethrin. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

19.
Arjunic acid and arjunolic acid are main bioactive components of Terminalia arjuna stem bark and reported for various biological activities. In this study, microwave-assisted extraction (MAE) of arjunic and arjunolic acid from stem bark of T. arjuna was investigated with developed and validated HPLC-PDA method, which resulted in the isolation of a novel anticancer molecule i.e. arjunic acid. Effects of several experimental parameters, such as type and volume of extraction solvents, microwave power, microwave extraction time, on the extraction efficiencies of arjunic, and arjunolic acid from stem bark of T. arjuna were evaluated. The optimal extraction conditions identified were 5.0 g quantity of stem bark powder, 20 mL of ethyl acetate, preleaching time 10 min, microwave power 600 W, temperature 65°C, and microwave irradiation time 5 min. The results showed that MAE is a more rapid extraction method with higher yield and lower solvent consumptions than reported methods. The HPLC-PDA analysis method was developed and validated to have good linearity, precision, sensitivity, and accuracy. MAE-HPLC-PDA is a faster, convenient, and appropriate method for isolation and determination of arjunic acid and arjunolic acid in the stem bark of T. arjuna.  相似文献   

20.
A novel graphene‐sensitized microporous membrane/solvent microextraction method named microporous membrane/graphene/solvent synergistic microextraction, coupled with high‐performance liquid chromatography and UV detection, was developed and introduced for the extraction and determination of three cinnamic acid derivatives in Rhizoma Typhonii. Several factors affecting performance were investigated and optimized, including the types of graphene and extraction solvent, concentration of graphene dispersed in octanol, sample phase pH, ionic strength, stirring rate, extraction time, extraction temperature, and sample volume. Under optimized conditions, the enrichment factors of cinnamic acid derivatives ranged from 75 to 269. Good linearities were obtained from 0.01 to 10 μg/mL for all analytes with regression coefficients between 0.9927 and 0.9994. The limits of quantification were <1 ng/mL, and satisfactory recoveries (99–104%) and precision (1.1–10.8%) were also achieved. The synergistic microextraction mechanism based on graphene sensitization was analyzed and described. The experimental results showed that the method was simple, sensitive, practical, and effective for the preconcentration and determination of cinnamic acid derivatives in Rhizoma Typhonii.  相似文献   

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