Quality evaluation of Radix Astragali through a simultaneous determination of six major active isoflavonoids and four main saponins by high-performance liquid chromatography coupled with diode array and evaporative light scattering detectors

A method, high-performance liquid chromatography coupled with diode array and evaporative light scattering detectors (HPLC-DAD-ELSD), was developed to evaluate the quality of Radix Astragali through a simultaneous determination of six major active isoflavonoids and four main saponins. The wavelength at 280 nm was chosen to determine six isoflavonoids: calycosin-7-O-beta-D-glucoside (1), ononin (2), (6alphaR, 11alphaR)-9,10-dimethoxypterocarpan-3-O-beta-D-glucoside (3), (3R)-2'-hydroxy-3',4'-dimethoxyisoflavan-7-O-beta-D-glucoside (4), calycosin (5), and formononetin (6); and ELSD connected after DAD was employed to determine four saponins: astragaloside IV (7), astragaloside II (8), astragaloside I (9), and acetylastragaloside I (10). This assay was fully validated with respect to precision, repeatability and accuracy. The proposed method was successfully applied to quantify the ten components in eleven samples from different localities in China; significant variations were demonstrated in the content of these compounds in the samples from different areas. This simple, rapid, low-cost and reliable HPLC-DAD-ELSD method is suitable for routine quantitative analysis and quality control of traditional Chinese medicines (TCMs) consisting of bioactive multi-components with different structures such as Radix Astragali.     

Simultaneous determination of bioactive constituents in Danggui Buxue Tang for quality control by HPLC coupled with a diode array detector,an evaporative light scattering detector and mass spectrometry

Danggui Buxue Tang (DBT), a classical traditional Chinese formula comprising Radix Angelicae Sinensis (RAS) and Radix Astragali (RA), has been widely used to treat menopausal irregularity in Chinese women for nearly 800 years. In this study, a comprehensive analytical method of simultaneously determining the main types of bioactive constituents, eighteen in all from the formula, involving flavonoids, saponins, organic acid and some volatile compounds, was developed. This method was based on HPLC coupled to a diode array and evaporative light scattering detectors (HPLC-DAD-ELSD) on a common reverse-phase C(18) column. Liquid chromatography coupled with on-line electrospray ionization mass spectrometry (LC-ESI-MS) was also used to further validate and analyze the constituents. It was found that 0.3% aqueous formic acid and acetonitrile was the optimum mobile phase for gradient elution. This method, which showed good precision and accuracy, was successfully used to quantify the bioactive constituents in six products. As a result, the validated HPLC method, together with the LC-ESI-MS analysis, provided a new basis for assessing the quality of traditional Chinese medicinal compound preparations (TCMCPs) consisting of many bioactive components.     

Application of high-performance liquid chromatography-electrospray ionization time-of-flight mass spectrometry for analysis and quality control of Radix Astragali and its preparations

A high-performance liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry (HPLC-ESI-TOF-MS) method has been developed for qualitative and quantitative analysis of isoflavonoids and saponins, as well as for the quality control of Radix Astragali and its preparations. The selectivity, reproducibility and sensitivity are compared with HPLC with diode array detection (DAD) and evaporative light scattering detection (ELSD). Limits of detection and quantification fell in ranges of 9-40 and 23-103 ng/mL for 13 analytes with a injection of 10 microL samples, and all calibration curves showed good linear regression (r(2)>0.9938) within the test range. The assay was successfully utilized to analyze the 13 marker components in 20 samples of Radix Astragali products. The quantitative results demonstrated that samples from different localities and manufacturers showed different quality. Advantages, in comparison with conventional HPLC-DAD-ELSD, are that reliable identification of target compounds could be achieved by accurate mass measurements (<3 ppm) along with characteristic retention time, extracted ions chromatograms using a narrow mass window for quantification ensure that the chromatographic peaks are free from background or co-elutes interference, and the great enhancement in selectivity and sensitivity allows identification and quantification of low levels of constituents in complex Radix Astragali matrixes.     

Simultaneous determination of major bioactive components in Qingkailing injection by high-performance liquid chromatography with evaporative light scattering detection

High-performance liquid chromatography with evaporative light scattering detection (HPLC/ELSD) was established for simultaneous determination of seven major bioactive components of Qingkailing injection including adenosine, geniposide, chlorogenic acid, baicalin, ursodeoxycholic acid, cholic acid, and hyodeoxycholic acid. The proposed method was applied to analyze ten various Qingkailing injections and produced data with acceptable linearity, repeatability, precision and accuracy having a limit of detection (LOD) of 10-50 ng. In comparison with UV detection, HPLC/ELSD permits the determination of non-chromophoric compounds without prior derivatization, and shows good compatibility to the multi-components of complex analytes. The proposed method is a useful alternative for routine analysis in the quality control of traditional Chinese medicine.     

Simultaneous qualification and quantification of eight triterpenoids in radix achyranthis bidentatae by high-performance liquid chromatography with evaporative light scattering detection and mass spectrometric detection

An HPLC with evaporative light scattering detection (ELSD) and ESI-MS was established for the simultaneous determination of eight triterpenoids in Radix Achyranthis Bidentatae. The optimal chromatographic conditions were achieved on a Zorbax C18 column by linear gradient elution with 0.08% v/v aqueous formic acid and ACN as the mobile phase at the flow rate of 0.8 mL/min. Temperature for the detector drift tube was set at 101 degrees C and the nitrogen flow rate was 2.8 L/min. The identities of the analytes were accomplished by comparing retention times and mass data with those of reference compounds. The validation of the method included tests of linearity, sensitivity, repeatability, recovery, and stability. All the calibration curves of the eight triterpenoids showed good linear regression (R2 >0.997) within the test ranges. The method provides desirable repeatability with overall intra- and interday variations of less than 4.9%. The obtained recoveries varied between 93.6 and 98.1% while the RSDs were below 3.9% (n = 3). The analysis results indicate that the content of investigated triterpenoids in Radix Achyranthis Bidentatae from different locations was greatly diverse, and the triterpenoids could be used as chemical markers for the discrimination of genuine and ungenuine crude drugs.     

清开灵注射液HPLC/ELSD指纹图谱建立及质量相关性研究

运用高效液相色谱／蒸发光散射检测器(HPLC／ELSD)建立了复方清开灵注射液的指纹图谱。对其中7种有效成分进行了定量测定,方法学考察结果良好;通过指纹图谱相似度评价软件,对10批清开灵注射液的HPLC／ELSD指纹图谱进行了相似度计算,结果表明：10批样品相似度很好。该方法为中药质量控制提供了一种可以同时实现整体定性、指标成分定量且简便易行的方法模式。     

应用高效液相色谱-二极管阵列检测器-蒸发光散射检测器联用技术同时测定清开灵注射液中的五类有效成分

建立了复方清开灵注射液中5类主要有效成分的定量测定方法。应用高效液相色谱-二极管阵列检测器-蒸发光散射检测器联用技术(HPLC-DAD-ELSD),根据各类成分紫外吸收光谱的差异,分别在240,254,280和330 nm波长下检测栀子苷、核苷(包括尿苷和腺苷)、黄芩苷和有机酸(包括绿原酸和咖啡酸)等4类成分,同时使用ELSD测定胆酸、熊去氧胆酸和猪去氧胆酸等3种甾体化合物,从而实现了清开灵注射液中5类有效成分(共9个化合物)的同时分离和定量测定。用该法测定了3个不同厂家的19批清开灵注射液成品。该法快速、准确,操作相对简单,为中药复方复杂体系的多组分定量测定和质量控制提供了一种可靠、合理且简便、易行的方法模式。     

Comparative study on major bioactive components in natural, artificial and in-vitro cultured Calculus Bovis

Major bioactive components in various Calculus Bovis, including natural, artificial and in-vitro cultured Calculus Bovis, were comparatively studied. An approach of high-performance liquid chromatography coupled with ultraviolet and evaporative light scattering detections (HPLC/UV/ELSD) was established to simultaneously determinate six bioactive components thereof, including five bile acids (cholic acid, deoxycholic acid, ursodeoxycholic, chenodeoxycholic acid, hyodeoxycholic acid) and bilirubin. ELSD and UV detector were applied to detect bile acids and bilirubin respectively. The assay was performed on a C(18) column with water-acetonitrile gradient elution and the investigated constituents were authenticated by comparing retention times and mass spectra with those of reference compounds. The proposed method was applied to analyze twenty-one Calculus Bovis extraction samples, and produced data with acceptable linearity, precision, repeatability and accuracy. The result indicated the variations among Calculus Bovis samples under different developmental conditions. Artificial and in-vitro cultured Calculus Bovis, especially in-vitro cultured ones, which contain total bioactive constituents no less than natural products and have the best batch-to-batch uniformity, suffice to be used as substitutes of natural Calculus Bovis.     

高效液相色谱/蒸发光散射法测定多黏菌素类原料药中主成分含量

建立了高效液相色谱/蒸发光散射法测定多黏菌素B和多黏菌素E原料药中主成分含量的分析方法。采用Phenomenex Kinetex Biphenyl色谱柱(50 mm×4.6 mm i.d.,5μm)分离,甲醇和20 mmol/L乙酸铵水溶液(含0.6%甲酸)为流动相,梯度洗脱,流速为0.5 mL/min;蒸发光散射检测器参数为:漂移管温度55℃,气体压力20 psi,增益250。结果表明,多黏菌素B和多黏菌素E在10～200μg/mL质量浓度范围内线性良好,检出限分别为0.8μg/mL和1.2μg/mL,定量下限分别为2.6μg/mL和4.0μg/mL。批内回收率分别为100%～104%和101%～103%,批内相对标准偏差(RSD)分别为0.90%～2.4%和0.90%～2.6%,批间回收率分别为101%～103%和101%～102%,批间RSD分别为1.1%～1.9%和1.3%～1.7%。与微生物检定法相比,该方法简便,能够更准确地反映原料药中目标分析物含量,精密度更高,可用于多黏菌素B和多黏菌素E两种原料药的质量控制。     

Determination of the enantiomers of 3-tert.-butylamino-1,2-propanediol by high-performance liquid chromatography coupled to evaporative light scattering detection

A method for the separation and quantitation of the enantiomers of 3-tert.-butylamino-1,2-propanediol by high-performance liquid chromatography and evaporative light scattering detection has been developed. Separation of the enantiomers was performed in normal-phase liquid chromatography on a Chiralpak AS chiral stationary phase. The influence of the gas nature, gas pressure and temperature of the drift tube of the evaporative light scattering detector on the detection sensitivity was investigated. The method was validated in terms of linearity, limit of quantitation, accuracy and precision. The enantiomeric excess of (S)-3-tert.-butylamino-1,2-propanediol, used for the industrial synthesis of (S)-timolol, was measured from 0 to 94%.     

Simultaneous determination of multiple platycosides with a single reference standard in Platycodi Radix by high‐performance liquid chromatography coupled with evaporative light scattering detection

A traditional external standard method using HPLC coupled with evaporative light scattering detection has been developed for fast and accurate determination of seven platycosides in Platycodi Radix. However, inevitable difficulties in reference standards preparation process, which are quite costly and time consuming, have made its application limited. To avoid this inconvenience, a simultaneous determination of multiple components with a single reference standard strategy, which could be realized by calibrating the standard curve with internal standard and response factors, was introduced to the HPLC coupled with evaporative light scattering detection method. This is the first time that an incorporation of these two methods has been realized. Among seven ingredients, platycodin D was selected as the internal standard for its relatively easy preparation and low cost. Moreover, according to the investigation on concentration‐dependent effects over response factors and robustness test, platycoside E, deapioplatycodin D, platycodin D, and polygalacin D₂ were chosen to be the indicators for this novel method. The present method has not shown statistically significant differences with a traditional external standard method as verified sample analysis by the F‐test (p = 95%, n = 6).     

Simultaneous quantitative determination of 13 active components in the traditional Chinese medicinal preparation Suanzaoren oral liquid by HPLC coupled with diode array detection and evaporative light scattering detection

To control the quality of different forms of Suanzaoren decoction, an effective and reliable method for the simultaneous determination of 13 major components (neomangiferin, mangiferin, spinosin, liquiritin apioside, liquiritin, 6′′′‐feruloylspinosin, senkyunolide I, timosaponin BII, isoliquiritoside, timosaponin C, jujuboside A, jujuboside B, and timosaponin AIII) was developed and validated for the first time in this study using high‐performance liquid chromatography with diode array detection and evaporative light scattering detection. The chromatographic separation was performed on a Venusil MP C₁₈ column (250 mm × 4.6 mm, 5 μm) at 30°C with a gradient of acetonitrile/redistilled water as the mobile phase. Diode array detection was carried out at a wavelength of 275 nm. The drift tube temperature and the nitrogen gas flow rate of the evaporative light scattering detection were set at 50°C and 1.6 L/min, respectively. The newly developed method was successfully applied to the determination of 13 components in lab‐prepared Suanzaoren oral liquid, Suanzaoren mixture, and clinical Suanzaoren granules, and this study showed that this was a useful way to comprehensively evaluate the quality of Suanzaoren decoction in different forms of the preparation.     

Simultaneous quantitation of three major triterpenoid glycosides in Centella asiatica extracts by high performance liquid chromatography with evaporative light scattering detection

A high-performance liquid chromatography method with evaporative light scattering detection was established for simultaneous determination of three major triterpenoid glycosides, i.e. asiaticoside, madecassoside and asiaticoside-B, in Centella asiatica extracts. The optimal chromatographic conditions were achieved on a COSMOSIL 5C(18)-MS-II column by constant elution with water (0.01% trifluoroacetic acid, v/v) and acetonitrile (1.0% methyl tert-butyl ether, 0.01% trifluoroacetic acid, v/v) (78:22) as mobile phase at a flow rate of 1.0 mL/min; the column temperature was 30 degrees C. The evaporative light scattering detector was set at an evaporating temperature of 40 degrees C and nitrogen gas pressure of 3.5 bar. The validation of the method included tests of linearity, sensitivity, precision, repeatability, stability and accuracy. All calibration curves showed good linear regression (r(2) > 0.9993) within test ranges. The established method showed good precision and accuracy with overall intra-day and inter-day variations of 1.73-3.06 and 3.89%-4.92%, respectively, and overall recoveries of 97.63-99.39% for the three compounds analyzed. The method developed was successfully applied to quantify the main triterpenoid glycosides in Centella asiatica extracts from different companies.     

Determination of seven compounds in Tang Maikang granule by high-performance liquid chromatography

An accurate and sensitive high-performance liquid chromatography method is developed and applied to the determination of seven compounds in a kind of traditional Chinese medicinal preparation of Tang Maikang Granule. The method is performed on Hypersil C(18) column (250- x 4.6-mm i.d., 5 microm), and different mobile phases and detectors are selected according to the various compounds. For astragaloside IV, an evaporative light scattering detector (ELSD) is used with a gradient of methanol-water at an eluent gas rate of 2.0 mL/min, under a drift tube temperature of 80 degrees C. Formononetin and calycosin are also eluted by a gradient of methanol-water, but a photodiode array (PDA) detector is used at a wavelength of 254 nm for formononetin and calycosin. A PDA detector at a wavelength of 230 nm is used for paeoniflorin, with methanol-water (30:70, v/v) as the mobile phase. For danshensu and protocate chualdehyde, an eluent of methanol-0.5% acetic acid (12:88, v/v) is used, with PDA detection at 280 nm. For berberine, methanol and water containing 0.1% sodium dodecanesulphonate (SDS) and 0.1% phosphorous acid (70:30, v/v) is employed as the mobile phase, also using a PDA detector, but the detection wavelength is 265 nm. The intra- and interrun precision (relative standard deviation) of this method is less than 5% for seven analytes.     

Determination of the enantiomers of 3-tert.-butylamino-1,2-propanediol by high-performance liquid chromatography coupled to evaporative light scattering detection

A method for the separation and quantitation of the enantiomers of 3-tert.-butylamino-1,2-propanediol by high-performance liquid chromatography and evaporative light scattering detection has been developed. Separation of the enantiomers was performed in normal-phase liquid chromatography on a Chiralpak AS chiral stationary phase. The influence of the gas nature, gas pressure and temperature of the drift tube of the evaporative light scattering detector on the detection sensitivity was investigated. The method was validated in terms of linearity, limit of quantitation, accuracy and precision. The enantiomeric excess of (S)-3-tert.-butylamino-1,2-propanediol, used for the industrial synthesis of (S)-timolol, was measured from 0 to 94%.     

Chemical Profiling and Quantification of Potential Bioactive Components in Gandouling Pill by Ultra-High Performance Liquid Chromatography Coupled with Diode Array Detector/Quadruple-Qrbitrap Mass Spectrometry

Gandouling (GDL) Pill is a novel Traditional Chinese medicinal drug to treat Wilson’s disease in clinics. It is composed of six separate herbal medicines, including Rhei Radix ET Rhizoma, Coptidis Rhizoma, Salviae Miltiorrhizae Radix ET Rhizoma, Spatholobi Caulis, Curcumae Rhizoma, and Curcumae Longae Rhizoma. In this study, a strategy was proposed to investigate the chemical constituents and to quantify the potential bioactive components in GDL Pill. Firstly, the mass fragmentation behaviors of representative compounds were investigated, and, in total, 69 compounds were characterized in GDL Pill using full scan/dd-MS² scan mode by ultra-high-performance liquid chromatography (UPLC)/Q-Orbitrap mass spectrometry (MS). These compounds included 18 alkaloids, 18 ketones, 16 phenolic compounds, 11 organic acids, and 6 tanshinones. Seventeen of the compounds were unambiguously identified by comparison with reference standards. Secondly, the absorption components of GDL Pill in rat plasma were investigated by using target-Selected Ion Monitoring (t-SIM) scan mode built in Q-Orbitrap MS. A total of 18 components were detected, which were considered as potential bioactive components of GDL Pill. Thirdly, 10 major absorption components were simultaneously determined in six batches of samples by UPLC/diode array detector (DAD). The method was fully validated with respect to linearity, precision, repeatability, stability, and recovery. Alkaloids from Coptidis Rhizoma, such as coptisine (8), berberine (18), palmatine (19), were the most abundant bioactive compounds for GDL Pill that possess the potential be used as quality markers. The proposed strategy is practical and efficient for revealing the material basis of GDL Pill, and also provides a simple and accurate method for quality control.     

Quantitation of seven polyoxypregnane glycosides in Marsdenia tenacissima using reversed-phase high-performance liquid chromatography-evaporative light-scattering detection

A high-performance liquid chromatography coupled with an evaporative light scattering detector (HPLC-ELSD) has been developed for the simultaneous determination of seven polyoxypregnane glycosides, tenacissosides A, B, G, H, I and marsdenosides C, G, in the stem of Marsdenia tenacissima, a Chinese herbal medicine. With a C18 analytical column, the analytes were separated efficiently using methanol-water as the mobile phase in a gradient program. The method limits of detection ranged from ca. 0.3 microg for marsdenoside C to ca. 0.5 microg for marsdenoside G and the method limits of quantitation from 1.0 microg for marsdenoside C to 1.7 microg for marsdenoside G, respectively. The intra- and inter-day precisions of the method were evaluated and all were less than 4%. All the recoveries for the spiked analytes exceeded 90%. This method was successfully used to analyze 19 samples of the stem of M. tenacissima.     

Determination of Biodiesel and Triacylglycerols in Diesel Fuel by LC

A high performance liquid chromatographic method was developed for quantifying blends of biodiesel (simple alkyl esters of fatty acids) in petrodiesel. The method uses a silica column with an isocratic mobile phase consisting of hexane and methyl t-butyl ether. Separated components were quantitated using either an evaporative light scattering detector (ELSD) or UV detector. Precision of injection and linearity of response of the ELSD and UV detectors over a range of biodiesel-petrodiesel blends [1–30 v/v %] were established by use of standards. The method also can be used for quantitating similar levels of oils or fats (triacylglycerols) in petrodiesel.     

Determination of nine active components in Radix Hedysari and Radix Astragali using capillary HPLC with diode array detection and MS detection

A capillary HPLC (cHPLC) coupled with diode array detection (DAD) and MS method was developed for the simultaneously qualitative and quantitative determination of nine components, namely vanillic acid, calycosin-7-O-beta-D-glucoside, (6alphaR,11alphaR)-9,10-dimethoxypterocarpan-3-O-beta-D-glucoside, ononin, calycosin, (3R)-2'-hydroxy-3',4'-dimethoxyisoflavan-7-O-beta-D-glucoside, isoliquiritigenin, formononetin, (3R)-8,2'-dihydroxy-7,4'-dimethoxyisoflavan, in Radix Hedysari (Hongqi) and Radix Astragali (Huangqi). Simultaneous separation of these nine compounds was achieved on a Zorbax C18 microcolumn (5 microm, 150 x 0.3 mm). The mobile phase consisted of (A) 0.3% aqueous formic acid and (B) ACN with a gradient elution. The identification of nine compounds in both Hongqi and Huangqi was confirmed by TOF-MS. All calibration curves showed good linearity (R(2) >0.998) within test ranges. This method showed good repeatability for the quantification of these nine components in Hongqi and Huangqi with intra- and inter-day variations of less than 1.89 and 3.13%, respectively. The validated method was successfully applied to quantify nine investigated components in eighteen samples of Hongqi and Huangqi. Hierarchical cluster analysis of 18 samples was performed using the peak area of nine analytes on cHPLC chromatograms. The result showed that Hongqi and Huangqi are significantly different, though the two species of Astragalus are very similar.