查找使用阿拉丁产品的科研文献

Comprehensive online two-dimensional liquid chromatography coupled to hybrid linear ion trap Orbitrap mass spectrometry with optimized dilution and modulation for analysis of Huangqi Guizhi Wuwu decoction

Jiang Maoyuan,Hua Shiyao,Zou Liang,Wang Yitao,Li Peng

Huangqi Guizhi Wuwu decoction (HGWD), as a classical formula, has been used for thousands of years in China. In this work, a comprehensive strategy was proposed for characterizing the chemical profile of HGWD based on online two-dimensional hydrophilic interaction and reversed-phase liquid chromatography coupled with hybrid linear ion trap-Orbitrap mass spectrometry (online HILIC × RP-ESI/HRMS/MS n ). The compounds in HGWD were first separated by the combined use of an XBridge amide column (150 × 4.6 mm, 3.5 μm) and Accucore C18 column (50 mm × 4.6 mm, 2.6 μm). Modulation with assistant technology, including trap columns and online dilution, was optimized and developed to decrease potential analyte loss and improve the resolution of the system. Subsequently, the accurate mass was determined by high-resolution Orbitrap and MS n fragment data by a hybrid linear ion trap (LTQ). In total, 170 chemical constituents were unambiguously identified or tentatively characterized in both positive and negative ion modes. Our study demonstrated that the proposed online HILIC × RP system coupled to the LTQ-Orbitrap MS platform is an efficient analytical technique for characterizing the chemical profile of multicomponent systems.

Miniaturized thermal purge-and-trap device combined with self-calibration colorimetric/SERS dual-model optical sensors for highly rapid and selective detection of sulfur dioxide in wine

Yun Wu,Meiqi Wang,Ying Gu,Kun Ge

Herein, the miniaturized thermal purge-and-trap (MTPT) device combined with self-calibration colorimetric/surface-enhanced Raman spectroscopy (SERS) dual-model optical sensors were designed for effective analysis of sulfur dioxide (SO 2 ) in wine. The SO 2 can be rapidly separated from wine and enriched by MTPT device, ensuring colorimetric/SERS dual-model optical sensing based on Karl Fischer reaction. The high separation efficiency of miniaturized MTPT device combined with self-calibration of dual-model optical sensors significantly alleviate matrix interference and improve the detection accuracy. The satisfactory linear range of 0.1–200.0 mg/L and 0.1–500.0 mg/L with limit of detection of 0.03 mg/L can be obtained. Finally, the MTPT-colorimetric/SERS method was applied to determine the content of SO 2 in different kinds of wine to verify the practicality. These results provide an ideal strategy in construction of MTPT device combined with self-calibration dual-model optical sensors for quantification of gaseous hazards in complex food samples with high rapidity, anti-interference and accuracy.

Flexible and powerful strategy for qualitative and quantitative analysis of valepotriates in Valeriana jatamansi Jones using high-performance liquid chromatography with linear ion trap Orbitrap mass spectrometry

Chunguo Wang,Zhiquan Zheng,Xinqi Deng,Xiaojie Ma,Shengnan Wang,Jie Liu,Yong Liu,Jinli Shi

Valeriana jatamansi Jones is an important medicinal plant and its quality is closely related to its region of origin. In the current study, we utilized a flexible and powerful strategy for comprehensive evaluation of the quality diversity for 15 regions in China. The method was based on a hybrid linear ion trap-Orbitrap mass spectrometry platform. For structure characterization, fragmentation patterns were detected by analyzing a series of standard compounds using data dependent multistage mass spectrometry acquisition. A fragment ion database for valepotriates was established, and the acquired data were high throughput filtered by fragment ion search for compound identification. For quantitative purposes, we normalized the mass spectrometry data of 15 samples using SIEVE 2.0 and the differences in composition were analyzed using principal component analysis combined with hierarchical clustering analysis. The results identified a total of 92 compounds from Valeriana jatamansi Jones. Samples from Dali, Kunming, and Baoshan have better qualities and concentrations of the main active constituents. To verify our strategy, we compared the valtrate, acevaltrate, and baldrinal contents using high-performance liquid chromatography with diode array detector. We developed and validated a comprehensive qualitative and quantitative analytical method to achieve quality control of Valeriana jatamansi Jones.

Ultra-Performance Liquid Chromatography–Electrospray Ionization–Ion Trap Tandem Mass Spectrometry for Fragmentation of Cyclic Dipeptides: Methodology and Application to the Chemical Profiling of the Fungus Hormonema dematioides

Min Jae Kim,Xinyun Zhang,Zhao Yang,Xiaofan Fan,Hongjuan Pan,Zhihong Cheng

Cyclic dipeptides (CDPs), distinguished by a 2,5-diketopiperazine core, exhibit a broad spectrum of biological activities. The (un)targeted discovery of CDPs in complex matrices is therefore of considerable interest, and mass spectrometry (MS) offers unrivalled advantages: rapid analysis, high sensitivity, minimal sample consumption, and limited pre-treatment requirements. Yet, confident MS-based identification of CDPs has been hampered by the scarcity of authentic reference standards. To address this deficit, we undertook a systematic investigation of 21 CDPs isolated from the fungus Hormonema dematioides using ultra-performance liquid chromatography–electrospray ionization–linear ion trap multistage MS (UPLC–ESI–LIT-MS n ) in positive ion mode. Hierarchical MS 2 and MS 3 experiments afforded reproducible fragmentation pathways that unambiguously delineated the CDP nucleus and the constituent amino acid residues. For the first time, we herein proposed [M + H-17] + and [M + H-56] + as co-diagnostic ions for the 2,5-diketopiperazine scaffold, together with the previously reported [M + H-28] + , [M + H-45] + , and [M + H-73] + ions. Additionally, in contrast to previous reports, the [M + H-28] + ion consistently appeared as the base peak for the majority of CDPs examined. Amino-acid-specific fragments were found to be strictly dependent on the nature of the incorporated residues. These fragmentation rules were subsequently applied to the untargeted profiling of H. dematioides , enabling the identification or tentative annotation of 30 CDPs through combined UV and MS n ( n = 3) data, corroborated wherever possible by authentic standards. Notably, 10 of the CDPs are reported here for the first time from this fungal species.

Unveiling the complexity of Astragali Radix by comprehensive two-dimensional hydrophilic interaction liquid chromatography × reversed phase liquid chromatography system coupled to hybrid linear ion trap Orbitrap mass spectrometry

Shiyao Hua,Jiayue Liu,Sijia Pu,Liang Zou,Lei Zhang,Peng Li

Comprehensive elucidation of the chemical constituents of Astragali Radix is crucial for its quality control and edible product development. Herein, online comprehensive two-dimensional hydrophilic interaction liquid chromatography × reversed phase liquid chromatography tandem high-resolution mass spectrometry was elaborately designed to separate, identify, and qualitatively compare various chemical components of Astragali Radix from two species. After selection and optimization of stationary phase, mobile phase, elution program and interface, an optimum method suitable for chemical components in Astragali Radix was established successfully. Under the optimized separation conditions, the orthogonality reached 99 %. A total of 212 compounds were identified and tentatively identified (198 from A. membranaceus var. mongholicus and 177 from A. membranaceus ). Additionally, the fragmentation pattern of flavonoids and saponins mass data in Astragali Radix have also been systematically studied. These findings not only unveiled multi-component complexity and diversity in two Astragalus species, but also proposed an innovative strategy for the rapid separation and identification of other complex systems.

Identification and dynamic analysis of the purine alkaloids in rat plasma after oral administration of green tea by liquid chromatography hybrid ion trap time-of-flight mass spectrometry

Mantong Song,Tiejie Wang,Qing Li,Longshan Zhao,Huijuan Fang,Dongxiang Li,Kaishun Bi

A liquid chromatography hybrid ion trap time-of-flight mass spectrometric (LC–IT-TOF-MS) method was developed and validated for identification and simultaneous determination of the potential bioactive components from green tea in rat plasma. The plasma samples were extracted by liquid–liquid extraction with ethyl acetate and separated on Shim-pack XR-ODS II column by a gradient elution within a runtime of 8.0   min. The mobile phase consisted of A (0.1% formic acid in acetonitrile) and B (0.1% formic acid in water) at a flow rate of 0.4   ml/min. Two prototype components and one metabolite were successfully identified as caffeine, theobromine and theophylline according to their retention times, accurate molecule weight, and major fragment ions. Then they were determined with the addition of two internal standards, hypoxanthine and paracetamol. The linear range was 10–10,000   ng/ml for caffeine, 2.0–2000   ng/ml for theobromine and 1.0–1000   ng/ml for theophylline, respectively. Intra-day and inter-day precision were within 6.0% and 10.9%, and accuracy was less than 4.8% and 6.5%, respectively. The validated method was successfully applied to investigate the dynamic change rules of caffeine, theobromine and theophylline in rat plasma after oral administration of caffeine, theobromine and green tea extract. The comparative analysis of the pharmacokinetic parameters indicated that there were obvious differences between green tea extract administration and single substances administration.

A Comparative Study of Gas-phase Fluorination and Nano-Al2O3 Doping on Space Charge Behavior and Trap Level in Epoxy Resin

Zijia Shen,Feipeng Wang,Muhammad Zeeshan Khan,Zhengyong Huang,Li He,Yushuang He,Jian Li

Quality consistency evaluation on three species of North Patrininae herba by high-performance liquid chromatography coupled with electrospray ion trap time-of-flight mass spectrometry and network pharmacology approaches

Qian Sun,Bing Wang,Lili Xu,Lewen Xiong,Dongxiao Guo,Weiliang Cui,Xingyan Xu,Yongqiang Lin

North Patrininae herba, a perennial herbaceous plant, has long been used in traditional Chinese medicine to treat appendicitis, enteritis, and dysentery. Sonchus arvensis L., Sonchus oleraceus L., and Ixeris chinensis (Thunb.) Nakai are used as substitutes for North Patrininae in different regions, but the consistency of chemical composition and efficacy of these three species is still unknown. In this study, a detailed chemical analysis was carried out of the extract obtained from Sonchus arvensis L., Ixeris chinensis (Thunb.) Nakai and Sonchus oleraceus L. and a chemical component not previously reported in Ixeris chinensis (Thunb.) Nakai was found—Luteolin-7- O -(6''-malonylglucoside). The mechanism of action of the extract against inflammation and type II diabetes was investigated using network pharmacology and analysis of blood-absorbed components following oral dosing of rats. Finally, a highly accurate and reliable method was established for quality control purposes. The results showed that Sonchus arvensis L. and Sonchus oleraceus L. may be considered potential resources of a medicinal compound, whereas Ixeris chinensis (Thunb.) Nakai requires further evaluation.

Simultaneous qualitative and quantitative analysis of 21 mycotoxins in Radix Paeoniae Alba by ultra-high performance liquid chromatography quadrupole linear ion trap mass spectrometry and QuEChERS for sample preparation

Yanyan Xing,Wenting Meng,Wanyang Sun,Dongxiang Li,Zhiguo Yu,Ling Tong,Yunli Zhao

A high-throughput method for simultaneous qualitative and quantitative analysis of 21 mycotoxins in Radix Paeoniae Alba (RPA) was developed by coupling the modified QuEChERS method with ultra-high performance liquid chromatography quadrupole linear ion trap mass spectrometry (UHPLC-QqLIT-MS). The 21 mycotoxins were extracted and cleaned up using QuEChERS-based procedure, then further separated on a C18 column and detected by a hybrid triple quadrupole linear ion trap mass spectrometer equipped with electrospray ionization source in the multiple reaction monitoring-information dependent acquisition-enhanced product ion (MRM-IDA-EPI) mode. Under this technique, 13 mycotoxins were detected using acetonitrile and water containing 0.1% formic acid as the mobile phase in positive mode while the other 8 mycotoxins were detected using acetonitrile and water containing 0.1% ammonia as the mobile phase in negative mode. The calibration curves of all analytes showed good linearity ( r 2   >   0.995) within test ranges. The limits of detection and quantification ranged from 0.031 to 5.4   µg/kg and 0.20 to 22   µg/kg, respectively. Additionally, recoveries were all above 75.3% with relative standard deviations within 15%. The method proposed herein with significant advantages including simple pretreatment, rapid determination as well as high sensitivity, accuracy and throughput would be a preferred candidate for the determination and quantification of multi-class mycotoxin contaminants in real samples.

An on-line high-performance liquid chromatography–diode-array detector–electrospray ionization–ion-trap–time-of-flight–mass spectrometry–total antioxidant capacity detection system applying two antioxidant methods for activity evaluation of the edible flowers from Prunus mume

Xiaoxia Zhang,Zongtao Lin,Jinggui Fang,Meixian Liu,Yanyan Niu,Shizhong Chen,Hong Wang

An on-line high-performance liquid chromatography−diode-array detector−electrospray ionization−ion-trap−time-of-flight−mass spectrometry−total antioxidant capacity detection (HPLC−DAD−ESI−IT−TOF−MS−TACD) system was created for identification and evaluation of antioxidants in Prunus ( P. ) mume flowers. Applying this system, the HPLC fingerprint, ultraviolet (UV) spectra, mass fragmentations, active profiles against 1,1-diphenylpicryl-2-hydrazyl radical (DPPH•) scavenging activity and ferric reducing antioxidant power (FRAP) of each complex sample were obtained simultaneously after one injection. Synchronous structure identification and activities screening of complex samples were thus accomplished. In this study, 78 compounds were identified from P. mume flowers by their chromatographic behaviors, UV spectra and MS data with the assistance of standard compounds and literature reports. The DPPH and FRAP activity of 24 samples (23 different P. mume varieties and 1 related herbal medicine) were then quantified by their detailed activity profiles from the on-line system, and by the total activity of each sample extract from off-line 96-well plate method. As a result, 21 and 32 compounds in the on-line system showed anti-oxidative effects against DPPH and FRAP, respectively. The established on-line system is efficient, sensitive and reliable to tell the DPPH and FRAP antioxidant activities of individual compound in complex samples, and therefore would be a useful and promising technique for antioxidant screening from different food and medicinal matrices.