Characterization and quantification of chemical constituents in Fuzhuan brick tea using ultra-high-performance liquid chromatography–mass spectrometry

Fuzhuan brick tea, a distinctive dark tea fermented by microorganisms, is a traditional beverage in China throughout history. Recently, it has attracted considerable attention owing to its unique quality characteristics and potential health benefits. The aim of this study was to establish a method for the quality control of Fuzhuan brick tea for stable production. Ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry was used to identify Fuzhuan brick tea, and the major components were chosen for further quantitative analysis. Subsequently, a quantification method was developed using ultra-high-performance liquid chromatography coupled with triple-quadrupole mass spectrometry, and its reliability was verified through methodological validation. Finally, a total of 30 compounds were identified, including catechins, flavonoids, alkaloids, and fatty acids. The established method was reliable for methodological validation and was applied to the quantitative analysis of Fuzhuan brick tea. This study provides a fundamental basis for the quality control and further studies on the component analysis of Fuzhuan brick tea.     

The chemical profile of active fraction of Kalimeris indica and its quantitative analysis

Kalimeris indica (L) Sch-Bip is a medicinal plant used by the Miao ethnic group in the Guizhou province of China. It is widely used as a fresh vegetable to treat colds, diarrhea and gastric ulcers. However, few studies have been conducted on the mechanism of its effect on colds, and its quality control. The anticomplement and antitussive activities of different polar extracts of K. indica were evaluated. Fifty-nine compounds, mainly including phenols and flavonoids, were identified in K. indica extract by ultra-high-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry. A method was established through ultra-high-performance liquid chromatography with a photodiode array to simultaneously determine the anticomplement and antitussive activity of five compounds in K. indica combining chemical identification with chemometrics for discrimination and quality assessment. Also, 3,5-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid exhibited significantly higher anticomplementary activity than the other three compounds. The quantitative data were further analyzed by principal component analysis and orthogonal partial least-squares discriminant analysis. Heatmap visualization was conducted to clarify the distribution of the major compounds in different geographical origins. Screening pharmacological activities by a combination of chemometrics and chemical identification might be an effective method for the quality control of K. indica.     

Comprehensive metabolite profiling of Plantaginis Semen using ultra high performance liquid chromatography with electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry coupled with elevated energy technique

Plantaginis Semen is commonly used in traditional medicine to treat edema, hypertension, and diabetes. The commercially available Plantaginis Semen in China mainly comes from three species. To clarify the chemical composition and distinct different species of Plantaginis Semen, we established a metabolite profiling method based on ultra high performance liquid chromatography with electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry coupled with elevated energy technique. A total of 108 compounds, including phenylethanoid glycosides, flavonoids, guanidine derivatives, terpenoids, organic acids, and fatty acids, were identified from Plantago asiatica L., P. depressa Willd., and P. major L. Results showed significant differences in chemical components among the three species, particularly flavonoids. This study is the first to provide a comprehensive chemical profile of Plantaginis Semen, which could be involved into the quality control, medication guide, and developing new drug of Plantago seeds.     

Qualitative and quantitative analysis of diterpenoids in Salvia species by liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry

An on-line ultra-high-performance liquid chromatography (UHPLC) coupled with photodiode-array detection and quadrupole time-of-flight tandem mass spectrometry (QTOF-MS/MS) method has been optimized and established for the qualitative and quantitative analysis of the important diterpenoids in the methanol extracts of 12 Salvia species. Specific marker components were identified for the classification of the Salvia samples by principal component analysis. The accurate mass measurement within 3 ppm error for all the protonated molecules and subsequent fragment ions offers higher quality structural information for interpretation of fragmentation pathways of various groups of diterpenoids. Thus, a total of 21 diterpenoids from different Salvia species were separated within 10 min, and were unequivocally or tentatively identified via comparisons with authentic standards and literature. This UHPLC-QTOF-MS/MS method was validated to be sensitive, precise and accurate with the limit of detections at 3.0–16 ng/ml, and the overall intra-day and the inter-day variations less than 3%. The recovery of the method was in the range of 96.2–101.8%, with relative standard deviation (RSD) less than 3.0%. The results demonstrated that the qualitative and quantitative differences in diterpenoids were not only useful for chemotaxonomy in some Salvia species but also for the standardization and differentiation of large numbers of similar samples.     

Qualitative identification and quantitative comparison of Physochlainae Radix from different regions based on chemometric methods

Physochlainae Radix (PR) is an essential herbal medicine that has been generally applied for treating cough and asthma. In this study, a comprehensive strategy for quality evaluation of PR from different origins was established by integrating qualitative identification, quantitative analysis, and chemometric methods. A total of 58 chemical components were identified by ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UHPLC-Q-TOF-MS/MS), and a sensitive and rapid UHPLC-QqQ-MS/MS method was established for the simultaneous determination of 12 compounds. In addition, multivariate statistical analysis was applied for discriminant analysis to compare the differences among 30 batches of PR samples. The results showed that the 30 batches of PR collected from four provinces could be clustered into three categories, in which scoparone, protocatechuic acid, tropic acid, and scopolin were important components to distinguish the primary and non-primary producing areas, as well as superior and inferior products of PR. Chemometric results were consistent and validated each other, and systematically explained the intrinsic quality characteristics of PR. This study first demonstrated that LC-MS combined with multivariate statistical analysis, provided a comprehensive and effective means for quality evaluation of PR.     

Comparative analysis of absorbed ingredients and metabolites,and pharmacokinetic studies of Zhimu–Huangbai herb pair in the plasma of normal and type 2 diabetes mellitus rats by UHPLC-linear trap quadrupole-orbitrap MS and LC-MS/MS

A new rapid ultra-high-performance liquid chromatography coupled with linear trap quadrupole orbitrap mass spectrometry method was established for the qualitative analysis of absorbed ingredients and metabolites of Zhimu–Huangbai herb pair, which is used to treat type 2 diabetes mellitus. A total of 16 absorbed ingredients and 11 metabolites were identified in normal and type 2 diabetes mellitus rats, respectively. Such findings indicated that the diabetic model had no effect on the type of components in plasma. Seven absorbed ingredients and 11 metabolites were first identified after the oral administration of Zhimu–Huangbai herb pair. Thereafter, ultra-high-performance liquid chromatography coupled with linear trap quadrupole orbitrap mass spectrometry and liquid chromatography-API4000⁺ triple quadrupole mass spectrometer methods were established and validated for pharmacokinetic comparative studies of seven major bioactive components in normal and type 2 diabetes mellitus rats. Partial pharmacokinetic parameters in the plasma of type 2 diabetes mellitus rats were significantly different from those in normal rats. To our knowledge, this is the first comparison of absorbed ingredients and metabolites of Zhimu–Huangbai herb pair, and its use in pharmacokinetic studies between normal and type 2 diabetes mellitus rats. Ultimately, our findings provide insights into the clinical usage of Zhimu–Huangbai herb pair.     

UPLC-MS/MS method for the determination of acrylic acid in tap water

Abstract

A simple and rapid method employing ultra-high performance liquid chromatography tandem mass spectrometry has been developed for the direct determination of acrylic acid in tap water for the first time. The method worked on a ultra-high-performance liquid chromatography system and utilized the direct injection of 10?μL volumes. Aqueous samples were filtered with 0.22?μm membrane after diluting with the acetonitrile without any further pretreatment. The separation was accomplished by using a HILIC column with a gradient elution program. Acetonitrile and ammonium acetate solution (pH = 7) were applied in the method as the mobile phase. Acrylic acid- d₃ was used as the internal standard in the quantification process. The method provided good recovery from 102.8% to 104.4%, good precision with intraday relative standard deviations in a range of 2.3% and 5.1%. The limit of quantification for the method was 45?μg/L. The possible structures of qualitative ion and quantitative ion of acrylic acid were proposed in this work with the help of the product ion spectra of acrylic acid and its corresponding isotopic standards. This study provided a reliable and quantitative method that could be used for daily monitoring of water quality.     

高效液相色谱-光电二极管阵列-高分辨质谱联用鉴定马鞭草提取物中的化学成分

采用高效液相色谱-光电二极管阵列-高分辨质谱联用(HPLC-PDA-HRMS)技术对马鞭草中的主要化学成分进行分析和鉴定。通过综合分析所检测到化合物的色谱、一级和多级全扫描质谱数据,对马鞭草提取物中的化学成分进行分析鉴定。马鞭草提取物中检测到环烯醚萜苷类、黄酮类、三萜类、苯乙醇苷类和二萜酚类化合物等共21种化学成分,其中鼠尾草酸、鼠尾草酚、迷迭香酚、异迷迭香酚、迷迭香酸以及金合欢素-7-O-芸香糖苷6种化合物并未在其他有关马鞭草提取物鉴定的文献中出现。该方法简单快速,准确度高,为鉴定中药材真伪和品质提供了可靠的科学依据。     

Chemical profiling and characterization of phenolic acids,flavonoids, terpene glycosides from Vangueria agrestis using ultra-high-performance liquid chromatography/ion mobility quadrupole time-of-flight mass spectrometry and metabolomics approach

Vangueria agrestis is a shrub indigenous to tropical Africa, belonging to family Rubiaceae and is traditionally used as a decoction for treatment of fever, pain, and malaria. This study was undertaken to investigate the chemical constituents based on precursor exact mass and fragment ion information. The chemical profiling and structural characteristics of chemical constituents from methanolic extracts of dried aerial parts and roots of V. agrestis and dietary supplements were analyzed using ultra-high-performance liquid chromatography/ion mobility quadrupole time-of-flight mass spectrometry coupled with UNIFI platform and multivariate analysis in both negative and positive ion modes. A non-targeted ultra-high-performance liquid chromatography-mass spectrometry analysis was carried out to profile the chemical constituents of crude extracts of V. agrestis, and 73 compounds, including reference compounds, were identified. The fragments of flavonoids, monoterpene, and triterpene glycosides revealed the characteristic cleavage of glycosidic linkages, and the fragmentation pattern provided the identity of the sugars. This analytical method provides a quick method for quality assessment of dietary supplements. Finally, a chemometrics approach with multivariate statistical tools was used to visualize the differences between root and aerial parts of plant samples and to find the potential chemical markers that differentiate among these parts of V. agrestis samples and dietary supplements.     

Identification and quantification of cucurbitacin in watermelon frost using molecular networking integrated with ultra-high-performance liquid chromatography-tandem mass spectrometry

Watermelon frost, a traditional Chinese medicine produced using watermelon and Glauber's salt, has been widely used for the therapy of oral and throat disorders. Watermelon contains various phytochemical compounds including cucurbitacins and their glycoside derivatives, which have attracted considerable attention because of their medicinal values. However, whether the composition of cucurbitacins existed in watermelon frost was rarely reported. In this study, three cucurbitacins including cucurbitacin B, isocucurbitacin B, and cucurbitacin E were found from watermelon frost extract assisted by ultra-high-performance liquid chromatography-tandem mass spectrometry and molecular networking guided strategy, and the compounds were verified using standard solutions. Furthermore, a quantification method for simultaneously targeted analysis of cucurbitacins was established using ultra-high-performance liquid chromatography-tandem mass spectrometry operating in the multiple reaction monitoring mode. Among them, cucurbitacin B and cucurbitacin E in watermelon frost samples were determined, and the concentrations were 3.78 ± 0.18 and 0.86 ± 0.19 ng/ml, respectively. While isocucurbitacin B was not detected due to the lower content possibly. In conclusion, ultra-high-performance liquid chromatography-tandem mass spectrometry combined with molecular networking is a very useful technique for the rapid identification of unknown cucurbitacin components in watermelon frost.     

Rapid determination of flavonoids in licorice and comparison of three licorice species

A simple, sensitive and fast method for the simultaneous quantitation of 15 flavonoids in licorice based on an ultra high performance liquid chromatography coupled with triple quadrupole electrospray tandem mass spectrometry had been established and validated in this study. The analysis was performed on an ACQUITY HSS T3 column with gradient elution using a mobile phase consisted of A (0.1% formic acid in water)/B (acetonitrile) at a flow rate of 0.4 mL/min. Satisfactory separation of these compounds was obtained in less than 9 min. All calibration curves showed good linearity (r² = 0.9940) during the test ranges. The precision, repeatability, accuracy, limit of detection and limit of quantification were also fully investigated. The validated method was successfully applied for the simultaneous quantitation of 15 flavonoids in 106 licorice samples which contained 83 batches of G. uralensis, 14 batches of G. glabra and 9 batches of G. inflata. Furthermore, multivariate statistical analysis (using principal components analysis) was performed to classify the samples based on the contents of the 15 analyzed compounds. The results showed that all of these licorice samples were rich in flavonoids, although their contents were obviously various, and the proposed method could serve as a prerequisite for quality control of licorice products.     

Rapid identification of chemical compositions of three species of Schisandra chinensis by ultra-high-performance liquid chromatography quadrupole-orbitrap-mass spectrometry

Schisandra chinensis is a traditional Chinese medicine, which has played an important role in the field of medicine and food. In this study, ultra-high-performance liquid chromatography quadrupole-orbitrap-mass spectrometry was used to rapidly classify and identify the chemical compositions. Note that 32, 28, and 30 kinds of compounds were successfully identified from northern Schisandra chinensis, vinegar-processed Schisandra chinensis, and wine-processed Schisandra chinensis, respectively. The cleavage patterns of various components including lignans, organic acids, flavonoids, and terpenoids were summarized, and the effects of different processing methods on Schisandra chinensis were analyzed through chemical composition. This method realized the rapid classification and identification of raw Schisandra chinensis and two different processed products, and provided references for improving the traditional processing methods, strengthening quality control, and ensuring safe clinical application.     

Development and validation of a UHPLC method for the determination of flavonoids in red wine

A simple and fast ultra-high-performance liquid chromatography (UHPLC) method was developed for the identification and quantification of the following flavonoids in red wine: (+/-)-catechin, (-)-epicatechin, rutin, quercitrin, hesperidin, neohesperidin, (+/-)-naringenin, hesperetin, and chrysin. Chromatographic separation of the flavonoids was performed on a Chromolith Fast Gradient C18e column. A gradient elution was used with mobile phases consisting of 0.1% formic acid in water and acetonitrile. UV detection was performed at 280 nm. A complete separation of flavonoids was possible within 6 min. The calibration curves showed good linearity (R2 > or = 0.9990) in the selected range of each analyte; the LOD ranged between 0.06 and 0.19 microg/mL. An optimized sample preparation method utilized SPE. The Oasis HLB column with the highest recoveries was selected for the preconcentration step. This method was successfully applied to the determination of these flavonoids in the red wine samples with excellent results.     

Quality evaluation of Semen Cassiae (Cassia obtusifolia L.) by using ultra-high performance liquid chromatography coupled with mass spectrometry

A sensitive and reliable ultra-high performance liquid chromatography-electrospray ionization-tandem mass spectrometry has been developed and partially validated to evaluate the quality of Semen Cassiae (Cassia obtusifolia L.) through simultaneous determination of 11 anthraquinones and two naphtha-γ-pyrone compounds. The analysis was achieved on a Poroshell 120 EC-C(18) column (100 mm × 2.1 mm, 2.7 μm; Agilent, Palo Alto, CA, USA) with gradient elution using a mobile phase that consisted of acetonitrile-water (30 mM ammonium acetate) at a flow rate of 0.4 mL/min. For quantitative analysis, all calibration curves showed perfect linear regression (r(2) > 0.99) within the testing range. This method was also validated with respect to precision and accuracy, and was successfully applied to quantify the 13 components in nine batches of Semen Cassiae samples from different areas. The performance of developed method was compared with that of conventional high-performance liquid chromatography method. The significant advantages of the former include high-speed chromatographic separation, four times faster than high-performance liquid chromatography with conventional columns, and great enhancement in sensitivity. This developed method provided a new basis for overall assessment on quality of Semen Cassiae.     

Simultaneous high‐performance liquid chromatography with diode array detection and time‐of‐flight mass spectrometric confirmation of the ten bioactive compounds in Semen Sojae Preparatum

Semen Sojae Preparatum is one of the most widely used traditional Chinese medicines. A reliable and accurate high‐performance liquid chromatography with diode array detection method has been developed and validated for the quantitative determination of the ten bioactive compounds contained in Semen Sojae Preparatum. The samples were first extracted by pressurized liquid extraction using 80% ethanol at 100°C for 15 min and three static extraction cycles. Chromatographic separation was conducted on a C18 column using a mobile phase consisting of water and acetonitrile under gradient elution, and the detection wavelength was set at 210 nm. The samples were further analyzed on a high‐performance liquid chromatography with time‐of‐flight mass spectrometry system to confirm the determination results. All the ten analytes were well separated, and the calibration curves showed good linearity. The intra‐ and interday precisions were evaluated in terms of relative standard deviation values within the ranges of 0.20–1.43% and 0.40–4.78%, respectively. The recoveries for the ten analytes were all in the ranges of 96.2–104.3%, with relative standard deviation values < 3.85%. The established high‐performance liquid chromatography method could serve as a reliable and accurate method for the quality evaluation of Semen Sojae Preparatum from different origins.     

Performance in (Ultra-)high-performance liquid chromatography—How to qualify and optimize instruments in practice

This paper investigates the suitability of an ultra-high-performance liquid chromatography/high-performance liquid chromatography hybrid system for ultra-high-performance liquid chromatography applications. Thus, the effect of extra column band broadening, the gradient system, and the injection system were tested and optimized according to their capabilities. An increase of the theoretical plate number up to a factor of two is achieved by the optimization of the extra column volume into the typical ultra-high-performance liquid chromatography range (<10 μl). Moreover, for qualitative purposes injections of volumes typical for ultra-high-performance liquid chromatography methods are precise. Despite this, a lack of precision and accuracy was determined for the gradient system, and the dwell volume meets the typical specification range for conventional HPLC systems. Therefore, hybrid systems are the intercept between both spectra and are limitedly suitable for ultra-high-performance liquid chromatography applications. Another way to approximate ultra-high-performance liquid chromatography performance using a high-performance liquid chromatography system is superficially porous particles. Thus, H/u curves of 5 μm superficially porous and 3 μm fully porous particles were recorded in order to determine the effect of the particle technology resulting in comparable performance of the used stationary phases.     

Targeted quantitative analysis of monoterpenoid indole alkaloids in Alstonia scholaris by ultra-high-performance liquid chromatography coupled with quadrupole time of flight mass spectrometry

Monoterpene indole alkaloids exhibit structural diversity in herbal resources and have been developed as promising drugs owing to their significant biological activities. Confidential identification and quantification of monoterpene indole alkaloids is the key to quality control of target plants in industrial production but has rarely been reported. In this study, quantitative performance of three data acquisition modes of ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry including full scan, auto-MS² and target-MS², was evaluated and compared for specificity, sensitivity, linearity, precision, accuracy, and matrix effect using five monoterpene indole alkaloids (scholaricine, 19-epi-scholaricine, vallesamine, picrinine, and picralinal). Method validations indicated that target-MS² mode showed predominant performance for simultaneous annotation and quantification of analytes, and was then applied to determine monoterpene indole alkaloids in Alstonia scholaris (leaves, barks) after extraction procedures optimization using Box-Behnken design of response surface methodology. The variations of A. scholaris monoterpene indole alkaloids in different plant parts, harvest periods, and post-handling processes, were subsequently investigated. The results indicated that target-MS² mode could improve the quantitative capability of ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry for structure-complex monoterpene indole alkaloids in herbal matrices. Alstonia scholaris, monoterpene indole alkaloids, quadrupole time of flight mass spectrometry, qualitative and quantitative analysis, ultra-high-performance liquid chromatography     

Identification and quantitative analysis of the chemical constituents of Gandouling tablets using ultra-high-performance liquid chromatography with quadrupole time-of-flight mass spectrometry

Gandouling tablets are used in a clinical agent for the treatment of hepatocellular degeneration; however, their chemical constituents have not been elucidated. Here, we screened and identified the chemical constituents of Gandouling tablets using ultra-high-performance liquid chromatography (UHPLC)-quadrupole time of flight/mass spectrometry. A method for the quality evaluation of Gandouling tablets was developed by combining the UHPLC fingerprints and the simultaneous quantitative analysis of multiple active ingredients. For fingerprint analysis, 20 shared peaks were identified to assess the similarities among the 10 batches of Gandouling tablets and the similarity was >0.9. The levels of nine representative active ingredients were simultaneously determined to ensure consistency in quality. A total of 99 chemical components were identified, including 18 alkaloids, 20 anthraquinones, 13 flavonoids, 11 phenolic acids, 9 polyphenols, 7 phenanthrenes, 5 sesquiterpenes, 3 curcuminoids, 2 lignans, 2 isoflavones, 2 dianthranones, and 7 other components. The retention times, molecular formulae, and secondary fragmentation information of these compounds were analyzed, and the cleavage pathways and characteristic fragments of some of the representative compounds were elucidated. This systematic analysis used to identify the chemical components of Gandouling tablets lays the foundation for its further quality control and research on their pharmacodynamic substances.     

UPLC fingerprint analysis and identification of flavonoids in Scutellaria indica by UFLC-triple-quadrupole time-of-flight mass spectrometry

The aim of this study was to raise the quality control level of Scutellaria indica. A quick and stable ultra performance liquid chromatography method was established for the fingerprint analysis of S. indica. A total of 32 common peaks were marked with 10 batches S. indica detected in 30?min using similarity evaluation system for chromatographic fingerprint of traditional Chinese medicine (2004A version). Besides, a high-resolution mass spectrometer was used to identify flavonoids in S. indica. A total of 27 flavonoids in S. indica were identified. And a series of fragmentation regularities were obtained, which could be used for the identification of other flavonoids. Therefore, the established liquid chromatography–tandem mass spectrometer method could be successfully utilized for the quality control of S. indica.