查找使用阿拉丁产品的科研文献

“Quantity-effect” research strategy for comparison of antioxidant activity and quality of Rehmanniae Radix and Rehmannia Radix Praeparata by on-line HPLC-UV-ABTS assay

Li Hong-Ying,Fang Jiang-Ji,Shen Hua-Dan,Zhang Xue-Qiong,Ding Xiao-Ping,Liu Jun-Feng

Background Quantitation analysis and chromatographic fingerprint of multi-components are frequently used to evaluate quality of herbal medicines but fail to reveal activity of the components. It is necessary to develop a rational approach of chromatography coupled with activity detection for quality assessment of herbal medicines. Methods An on-line HPLC-ultraviolet detection-2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) free radical scavenging (HPLC-UV-ABTS) method was developed to obtain the chromatographic fingerprints and ABTS +• inhibition profiles (active fingerprints) of Rehmanniae Radix (Dihuang) and Rehmannia Radix Praeparata (Shu Dihuang). Eighteen compounds showing ABTS +• inhibition activity were identified by HPLC-fourier-transform mass spectrometry (HPLC-FTMS). Verbascoside was used as a positive control to evaluate the total activities of the samples and the contribution rate of each compound. The similarities of the chromatographic and active fingerprints were estimated by the vectorial angle cosine method. Results The results showed that the HPLC-UV-ABTS method could efficiently detect antioxidant activity of the herbal medicine samples. The antioxidants were different between the two herbs and several new antioxidants were identified in Shu Dihuang. A function equation was generated in terms of the negative peak area (x) and the concentrations of verbascoside (y, μg/mL), y = 2E-07 ×  4 - 8E-05 ×  3  + 0.0079 ×  2  + 0.5755x + 1.4754, R 2  = 1. Iridoid glycosides were identified as main antioxidants and showed their higher contributions to the total activity of the samples. The total contributions of the three main active components in the Dihuang and Shu Dihuang samples to the total activity, such as echinacoside, verbascoside and an unknown compound, were 39.2–58.1% and 55.9–69.4%, respectively. The potencies of the main active components in the Shu Dihuang samples were two to ten times those in the Dihuang samples. Similarity values for S12 in the chromatographic fingerprints and S03, S12 and P03 in the active fingerprints were less than 0.9. The three batches of samples might show their different quality with the other samples. Conclusions The results suggested that the combination of “quantity-effect” research strategy and the HPLC-UV-ABTS analysis method could comprehensively evaluate the active components and quality of Dihuang and Shu Dhuang.

Establishment of a HPLC–MS/MS Detection Method for Glyphosate, Glufosinate-Ammonium, and Aminomethyl Phosphoric Acid in Tea and Its Use for Risk Exposure Assessment

Yong Wang,Wanjun Gao,Yeyun Li,Yu Xiao,Wei Song,Ting Yao,Manhuan Cheng,Wenjuan Wang,Ruyan Hou

The tea shrub is grown in long-standing orchards, an environment that is suitable for persistent weed growth, which is increasingly controlled by herbicides. Therefore, there is increasing concern that tea consumers may be exposed to herbicide residues. In this study, the levels of glufosinate-ammonium (GLU), glyphosate [N-(phosphonomethyl) glycine; PMG], and its metabolite aminomethyl phosphoric acid (AMPA) were determined in tea samples by HPLC–MS/MS using several current purification methods and a new method that we developed herein. The matrix effect of our proposed method was between -27.3 and 27.7%, which was lower than that in other methods, indicating that this method effectively reduced the interference of tea matrix in the mass spectrometry process. This method was used to determine the levels of PMG, GLU, and AMPA in 780 samples, including six traditional Chinese teas (green tea, black tea, oolong tea, dark tea, white tea, and yellow tea) and a floral tea, from 14 provinces of China. Probability estimates showed that the 95th percentile risk entropy values of the three pesticide residues were far below the acceptable risk level. The risk assessment results showed that exposure to PMG, GLU, and AMPA caused by drinking tea beverages poses no significant risk to human health.

Polyethyleneimine-modified porous aromatic framework and silane coupling agent grafted graphene oxide composite materials for determination of phenolic acids in Chinese Wolfberry drink by HPLC

Yaying Lv,Tao Zhu

A simple method for the determination of phenolic acids in Chinese Wolfberry drink based on polyethyleneimine modified porous aromatic framework and graphene oxide composite sorbent for pipette-tip solid-phase extraction was developed. Porous aromatic framework and raphene oxide composite materials were grafted by silane coupling agent (3-Chloropropyl)-trimethoxysilane. The modified materials were characterized by five kinds of characterization. Experimental results showed that the prepared p-phenylenediamine, cyanuric chloride, and graphene oxide composite material had a loose structure combined with the framework which improved hydrophobicity, and polyethyleneimine to increase the selectivity with the targets. The parameters of the pipette-tip solid-phase extraction procedure including the amount of sorbents, volumes and types of washing solvents and elution solvents were optimized to achieve optimal extraction efficiency. Good linearity of best material was achieved in the range of 0.1–400 µg/mL with correlation coefficient of chlorogenic acid (0.9994), caffeic acid (0.9997), and ferulic acid (0.9998). Recoveries between 93.5 and 102.3% were obtained at three spiked levels with relative standard deviation ≤3.1%. The proposed method was successfully applied for the determination of phenolic acids in Chinese Wolfberry drink sample.

Development of Surface Molecularly Imprinted Polymers as Dispersive Solid Phase Extraction Coupled with HPLC Method for the Removal and Detection of Griseofulvin in Surface Water

Kamran Bashir,Zhimin Luo,Guoning Chen,Hua Shu,Xia Cui,Wen Li,Wang Lu,Qiang Fu

Griseofulvin (GSF) is clinically employed to treat fungal infections in humans and animals. GSF was detected in surface waters as a pharmaceutical pollutant. GSF detection as an anthropogenic pollutant is considered as a possible source of drug resistance and risk factor in ecosystem. To address this concern, a new extraction and enrichment method was developed. GSF-surface molecularly imprinted polymers (GSF-SMIPs) were prepared and applied as solid phase extraction (SPE) sorbent. A dispersive solid phase extraction (DSPE) method was designed and combined with HPLC for the analysis of GSF in surface water samples. The performance of GSF-SMIPs was assessed for its potential to remove GSF from water samples. The factors affecting the removal efficiency such as sample pH and ionic strength were investigated and optimized. The DSPE conditions such as the amount of GSF-SMIPs, the extraction time, the type and volume of desorption solvents were also optimized. The established method is linear over the range of 0.1–100 µg/mL. The limits of detection and quantification were 0.01 and 0.03 µg/mL respectively. Good recoveries (91.6–98.8%) were achieved after DSPE. The intra-day and inter-day relative standard deviations were 0.8 and 4.3% respectively. The SMIPs demonstrated good removal efficiency (91.6%) as compared to powder activated carbon (67.7%). Moreover, the SMIPs can be reused 10 times for water samples. This is an additional advantage over single-use activated carbon and other commercial sorbents. This study provides a specific and sensitive method for the selective extraction and detection of GSF in surface water samples.Keywords:dispersive solid phase extraction;griseofulvin;HPLC;removal and analysis;pharmaceutical pollutants;surface water

Quality Control of Gastrodia elata by High-Performance Liquid Chromatography with Fluorescence Detection (HPLC–FLD) and Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA)

Bocheng Yu,Zhen Li,Jinyi Wu,Jiamin Ying,Yuqing Tang,Bingchu Wu,Chunlan Tang,Jinyan Xu

A high-performance liquid chromatography with fluorescence detection (HPLC–FLD) and principal component analysis (PCA) and hierarchical cluster analysis (HCA) were developed for the quality control of Gastrodia elata. The developed protocols were successfully applied to the analysis and evaluation of 47 batches of this material from eight regions. A standard fluorescence fingerprint for G. elata was established based on 12 common peaks measured in all samples and the similarities between sample fingerprints and standard fingerprint were almost greater than 0.85. The results of PCA and HCA analysis showed that the samples from the eight regions could be classified into three groups. The correlation between the fingerprints and antioxidant activities was investigated by a stepwise regression model and Pearson correlation analysis. Gastrodigenin and parishin E were screened and validated as potential antioxidant markers of G. elata. This study provides a valuable reference for the evaluation of G. elata and other herbal medicines or their related foods.

Coupling mesoporous imprinted polymer based DGT passive samplers and HPLC: A new tool for in-situ selective measurement of low concentration tetrabromobisphenol A in freshwaters

Zhongmin Feng,Yun Wang,Lan Yang,Ting Sun

Accurate measurement of tetrabromobisphenol A (TBBPA) is very important because of its widespread environmental pollution . Diffusive gradients in thin films technique (DGT), an in-situ passive sampling method, is regarded as a reliable and robust measurement technique. A new DGT technique based on mesoporous imprinted polymer was combined with high-pressure liquid chromatography (HPLC) method for sampling, preconcentration and monitoring low concentration TBBPA in natural waters. The diffusion coefficient of TBBPA through the diffusive gel was measured by diffusion cell test and simulated using mathematical expression. The effects of different ambient conditions were tested under laboratory conditions and the performance of DGT sampler was validated in natural waters. The diffusion coefficient of TBBPA in the diffusive gel was measured as 2.18 × 10 −6  cm 2  s −1 and simulated as in the range 1.41–3.48 × 10 −6  cm 2  s −1 by Amsden model. Comparison of experimental and theoretical data, the validity of the experimental method can be verified by the mathematical model. The binding agent with mesoporous imprinted polymer showed selective affinity to TBBPA and its adsorption rate met the requirement of DGT device. The DGT method detection limit was at the level of ng L −1 for 7 days deployment. DGT sampler was suitable for application in aquatic environment with a range of pH (4.5–7.6), ionic strength (1 × 10 −4 - 0.5 mol L −1 ), and dissolved organic matter (DOM) concentration (0–10 mg C L −1 ). The coupling method of DGT and HPLC was a promising technique for in situ sampling, preconcentration and monitoring low concentration TBBPA in most typical natural waters.

A stable mesoporous metal-organic framework as highly efficient sorbent of dispersive micro solid-phase extraction for the determination of polycyclic aromatic hydrocarbons by HPLC

Lian Xia,Lijie Liu,Yanan Dou,Lan Guo,Guoliang Li,Zhiwei Sun,Jinmao You

Owing to the large molecular sizes of polycyclic aromatic hydrocarbons, their adsorption using microporous sorbents leads to a low adsorption capacity. Here, to increase the extraction capacity and detection sensitivity of polycyclic aromatic hydrocarbons, a highly efficient dispersive micro solid-phase extraction method was developed based on a stable mesoporous metal-organic framework named Jilin University China 48. Jilin University China 48 is a super hybrid with large one-dimensional hexagonal nanotube-like channels of 24.5 × 27.9 Å, which exhibits high potential to be an efficient sorbent of dispersive micro solid-phase extraction to adsorb polycyclic aromatic hydrocarbons. By combining with high-performance liquid chromatography, a sensitive method was developed for the determination of seven polycyclic aromatic hydrocarbons. The synthesized Jilin University China 48 exhibited excellent characteristics of stability, good morphology, large surface area, and open adsorption sites. Under the optimized extraction conditions, better extraction results were obtained than that of other methods reported previously. The proposed method exhibited high sensitivity with the limit of detections in the range of 0.021–0.13 ng/mL, good linearity in the range of 0.068–50 ng/mL with related coefficients of >0.9988, satisfactory precision with relative standard deviation of <4.3%, and adequate recoveries between 85.8 to 109.55% for all the target compounds.

A rapid, accurate and sensitive method for determination of monosaccharides in different varieties of Osmanthus fragrans Lour by pre-column derivatization with HPLC-MS/MS

Baolei Fan,Tingting Li,Xiaofang Song,Chao Wu,Chunqi Qian

A specific HPLC-MS/MS (High-Performance Liquid Chromatography with tandem Mass Spectrometry) method was developed and validated for simultaneous determination of several monosaccharides in three kinds Osmanthus fragrans Lour . After extraction, separation, protein removal, pigment removal and hydrolysis , monosaccharides was finally obtained from Osmanthus fragrans Lour . Positive ion mode detection and Multiple Reaction Monitoring (MRM) mode were used for quantitative analysis by PMP pre-column derivatization and Electrospray Ionization (ESI). Analysis and content determination of 6 monosaccharide components in 3 kinds of Osmanthus fragrans Lour . The HPLC separation was achieved on a Shim-pack VP-ODS6022748 (150 L × 2.0) with gradient elution at a flow rate of 0.2 ml/min in a run time of 40 min, and the mobile phase was acetonitrile-5 mmol/L ammonium acetate. PMP derivatization in HPLC-MS/MS can accurately measure Osmanthus fragrans Lour . mannose (Man), ribose (Rib), rhamnose (Rha), galacturonic acid (Gal UA), glucose (Glu), galactose (Gal), xylose (Xyl), fucose (Fuc). The results showed that HPLC-MS/MS pre-column derivatization method was simple and rapid, with small measurement error, but high sensitivity and good repeatability. The analysis of monosaccharide components in polysaccharide components has important practical significance.

Magnetic solid-phase extraction based on Fe3O4/graphene oxide nanoparticles for the determination of malachite green and crystal violet in environmental water samples by HPLC

Leilei Zhang,Yiying Zhang,Yurong Tang,Xiaorong Li,Xinfeng Zhang,Chaobi Li,Shuxia Xu

Determination of the degree of acetylation and the distribution of acetyl groups in chitosan by HPLC analysis of nitrous acid degraded and PMP labeled products

Zhangrun Han,Yangyang Zeng,Hong Lu,Lijuan Zhang

Chitin is one of the most abundant polysaccharides on earth. It consists of repeating β-1,4 linked N-acetylated glucosamine (A) units. Chitosan is an N-deacetylated product of chitin. Chitosan and its derivatives have broad medical applications as drugs, nutraceuticals , or drug delivery agents. However, a reliable analytical method for quality control of medically used chitosans is still lacking. In current study, nitrous acid was used to cleave all glucosamine residues in chitosan into 2,5-anhydromannose (M) or M at the reducing end of di-, tri-, and oligosaccharides . PMP , i.e. 1-phenyl-3-methyl-5-pyrazolone, was used to label all the Ms. Online UV detection allowed quantification of all M-containing UV peaks whereas online MS analysis directly identified 11 different kinds of mono-, di-, tri-, and oligosaccharides that correlated each oligosaccharide with specific UV peak after HPLC separation. The DA (degree of acetylation) for chitosans was calculated based on the A/(A+M) value derived from the UV data. This newly developed method had several advantages for quality control of chitosan: 1. the experimental procedures were extensively optimized; 2. the reliability of the method was confirmed by online LC-MS analysis; 3. the DA value was obtainable based on the UV data after HPLC analysis, which was comparableto that of 1 H NMR and conductometric titration analyses; 4. finally and most importantly, this method could be used to obtain the DA as well as chemical acetylation/deacetylation mechanisms for chitosan by any laboratory equipped with a HPLC and an online UV detector.

Development and Validation of a Stability-Indicating High Performance Liquid Chromatographic (HPLC) Method for the Determination of Related Substances of Micafungin Sodium in Drug Substances

Shengsheng Zhu,Xiang Meng,Xin Su,Yongwei Luo,Zuyue Sun

An isocratic, sensitive and stability-indicating high performance liquid chromatographic (HPLC) method for separation and determination of the related substances of micafungin sodium was developed. The chromatographic separation was achieved on Agilent Zorbax SB-C18 column (250 × 4.6 mm, 5 μm). Forced degradation study confirmed that the newly developed method was specific and selective to the degradation products. The performance of the method was validated according to the present ICH guidelines for specificity, linearity, accuracy, precision and robustness. Regression analysis showed correlation coefficient value greater than 0.999 for micafungin sodium and its six impurities. Limit of detection of impurities was in the range of 0.006%–0.013% indicating the high sensitivity of the newly developed method. Accuracy of the method was established based on the recovery obtained between 98.2% and 102.0% for all impurities. RSD obtained for the repeatability and intermediate precision experiments, was less than 1.0%. The method was successfully applied to quantify related substances of micafungin sodium in bulk drugs.Keywords:micafungin sodium;related substances;stability-indicating;forced degradation;validation

Ionic Liquid-Based Surfactant Extraction Coupled with Magnetic Dispersive μ-Solid Phase Extraction for the Determination of Phthalate Esters in Packaging Milk Samples by HPLC

Wang Meng,Yang Fan,Liu Le,Cheng Chunsheng,Yang Yaling

A highly selective sample cleanup procedure combining ionic liquid-based surfactant extraction (ILSE) and magnetic dispersive μ-solid phase extraction (MD-μ-SPE) was triumphantly developed for the synchronously extraction of four phthalate acid esters (PAEs) in packaging milk samples prior to high-performance liquid chromatography coupled with photodiode array detector (HPLC-DAD). In this ionic liquid (IL)-based surfactant method, 1-octyl-3-methylimidazolium hexafluorophosphate ([C 8 MIM] [PF 6 ]) was used as extraction solvent, anionic surfactant sodium linear alkylbenzene sulfonate (LAS) was used as auxiliary extraction solvent, and then sodium chloride (NaCl) was mixed to drive phase separation. The synthesized hydrophobic diatomaceous earth-supported Fe 3 O 4 magnetic nanoparticles (DSMNPs) were applied as an efficient adsorbent to retrieve the analyte-containing IL and LAS. Under the optimal extraction situations, good linearity of the approach was obtained in the concentration range from 10 to 1000 ng/mL for target analytes, and the preconcentration process was rapidly accomplished in 5 min. The limits of detection (LODs) based on a signal-to-noise ratio (S/ N  = 3) were ranged from 1.42 to 3.57 ng/mL with the relative standard deviations (RSDs) over the range of 1.84–3.56% ( n  = 5). The above-mentioned method was applied to the trace analysis of four PAEs including benzyl butyl phthalate (BBP), dicyclohexyl phthalate (DCHP), di-n-butyl phthalate (DBP), and di-n-octyl phthalate (DNOP) in packaging milk samples, and recoveries were between 89.8 and 99.7%.