Analytical Methods
·
2014
·Vol. 6
·期 5
·1563-1568
·
IF 1.938
Huang Yang,Li Kang,Shao Hui Kai,Liu Sheng Quan,Xiang Fei Jun
A method using molecularly imprinted solid-phase extraction combined with RP-HPLC-UV was developed for determination of liquiritin (LQR) in rat plasma after oral administration of Compound Liquorice Tablets (CLTs). To this end, molecularly imprinted polymers were prepared by in situ polymerization, using LQR as the template, acrylamide as the functional monomer, and ethylene glycol dimethacrylate as the crosslinker, whose solid-phase extraction properties for liquiritin were evaluated by HPLC-UV. The enrichment and extraction recovery were investigated in the study after the extraction procedure was optimized. The recovery was larger than 85.0% and the RSD was less than 10.0%. The calibration curve was expressed as y = 16 004x − 1.864 (r = 0.996) with a linear range of 0.007–1.683 μg mL−1. Besides, the Tmax was 0.5 h for liquiritin and the Cmax was 0.8 μg mL−1 after oral administration of compound liquorice tablets. In addition, the pharmacokinetic parameters were calculated using a two-compartment model. The results indicated that the monolithic polymer pipette presented a good extraction efficiency for liquiritin. At the same time, the results indicated that the index components could basically reveal the pharmacokinetic behavior. This study was aimed to explore an approach that could be applied to promulgate the pharmacokinetics and provide more information for clinical applications.
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MICROCHIMICA ACTA
·
2015
·Vol. 182
·期 9
·1791-1796
·
IF 3.741
Li Lu,Lin Zheng-zhong,Chen Xiao-mei,Zhang Hong-yuan,Lin Yi-dong,Lai Zhu-zhi,Huang Zhi-yong
Molecularly imprinted polymer (MIP) particles for malachite green (MG) were prepared by emulsion polymerization using methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, and a combination of Span-80 and Tween-80 as an emulsifier. The MIP particles were characterized by SEM micrographs and FT-IR spectra. Their binding capacity for MG was evaluated based on kinetic and isothermal adsorption experiments and compared to non-imprinted polymer particles. Analytical figures of merit include an adsorption equilibrium time of 15 min, an adsorption capacity of 1.9 mg∙g‾ 1 in acetonitrile-water (20:80), and an imprinting factor of 1.85. The MIP particles were successfully applied to the extraction of MG from fish samples spiked with MG and the other interfering substances prior to its determination of MG by HPLC. Spiked samples gave recoveries of MG that ranged from 86 to 104 %, much higher than that of the other interfering substance.
Molecularly imprinted polymer particles for malachite green (MG) were prepared by emulsion polymerization. They show adsorption capacity of 1.9 mg∙g‾¹ with imprinting factor of 1.85, and were successfully applied to the extraction of MG from spiked fish samples.
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CHROMATOGRAPHIA
·
2013
·Vol. 76
·期 23
·1649-1655
·
IF 1.437
Wu Anguo,Duan Tingting,Tang Dan,Xu Youhua,Feng Liang,Zheng Zhaoguang,Zhu Jiaxiao,Wang Rushang,Zhu Quan
Nitrite and nitrate are main stable products of nitric oxide, a pivotal cellular signaling molecule, in biological fluids. Therefore, accurate measurement of the two ions is profoundly important. Nitrite is difficult to be determined for a larger number of interferences and unstable in the presence of oxygen. In this paper, a simple, cost-effective and accurate HPLC method for the determination of nitrite and nitrate was developed. On the basis of the reaction that nitrite is oxidized rapidly to nitrate with the addition of acidic potassium permanganate, the determination of nitrite and nitrate was achieved by the following strategy: each sample was injected twice for HPLC analysis, i.e. the first injection was to measure nitrate, and the second injection was to measure total nitrate including initial nitrate and the nitrate from the conversion of nitrite with the addition of acid potassium permanganate in the sample. The amount of nitrite can be calculated as difference between injections 2 and 1. The HPLC separation was performed on a reversed phase C 18 column for 15 min. The mobile phase consisted of methanol–water (2:98 by volume); the water in the mobile phase contained 0.60 mM phosphate salt (potassium dihydrogen and disodium hydrogen phosphate) and 2.5 mM tetrabutylammonium perchlorate (TBAP). The UV wavelength was set at 210 nm. Additionally, we systemically investigated the effects of the concentration of phosphate salt and TBAP in the mobile phase, the pH of the mobile phase, and the amount of acidic potassium permanganate added to the sample on the separation efficacy. The results showed that the limits of detection (LOD) and the limit of quantitation (LOQ) were 0.075 and 0.25 μM for nitrate (containing the oxidized nitrite), respectively. The linear range was 1–800 μM. This developed approach was successfully applied to assay nitrite/nitrate levels in cell culture medium, cell lysate, rat plasma and urine.
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Materials
·
2017
·Vol. 10
·期 4
·440
·
IF 2.654
Bing Yu,Tao Xu,Hailin Cong,Qiaohong Peng,Muhammad Usman
By using the two-step activated swelling method, monodisperse porous poly(styrene-divinylbenzene) (P(S-DVB)) microparticles were successfully synthesized. The influence of porogens, swelling temperatures and crosslinking agents on the porosity of porous microparticles was carefully investigated. Porous P(S-DVB) microparticles were used as a packing material for high performance liquid chromatography (HPLC). Several benzene analogues were effectively separated in a stainless-steel column as short as 75 mm due to the high specific surface area of the porous microparticles. Porous P(S-DVB) microparticles were further sulfonated and subsequently modified with diazoresin (DR) via electrostatic self-assembly and UV (ultraviolet) radiation. After treatment with UV light, the ionic bonding between sulfonated P(S-DVB) and DR was converted into covalent bonding through a unique photochemistry reaction of DR. Depending on the chemical structure of DR and mobile phase composition, the DR-modified P(S-DVB) stationary phase performed different separation mechanisms, including reversed phase (RP) and hydrophilic interactions. Therefore, baseline separations of benzene analogues and organic acids were achieved by using the DR-modified P(S-DVB) particles as packing materials in HPLC. According to the π–π interactional difference between carbon rings of fullerenes and benzene rings of DR, C60and C70were also well separated in the HPLC column packed with DR-modified P(S-DVB) particles.Keywords:polystyrene;seeded polymerization;macroporous structures;diazoresin;high performance liquid chromatography
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TALANTA
·
2017
·
IF 4.162
Liang Li,Biaoping Cheng,Rendan Zhou,Zhigang Cao,Chun Zeng,Laisheng Li
A novel N -benzyl-phenethylamino-β-cyclodextrin-bonded ordered mesoporous SBA-15 chiral stationary phase (BZCDP) for high-performance liquid chromatography (HPLC) was prepared. The structure and morphology of the ligand and the stationary phase were characterized by mass spectrometry, elemental analysis , infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and thermogravimetric analysis . The enantiomers of chiral compounds including nine common β-adrenergic blocker drugs (β-blockers), eight dansyl amino acids (DNS-AA) and six flavanones were successfully separated by polar organic solvent and reversed-phase chromatography, respectively. The results showed that BZCDP was a kind of multimode chiral separation materials with an excellent chromatographic performance for the above compounds. In polar organic solvent mode, BZCDP can effectively separate β-blockers, in which the enantioselectivity factors and resolutions of β-blockers were up to 1.30 and 1.97 within 20 min, respectively. Under the reversed-phase mode, BZCDP exhibited high enantioselectivities for DNS-AA, among them the resolution of dansyl-tyrosine was 3.29 with 20 min. BZCDP was also successfully used to separate the flavanone compounds with methanol or acetonitrile as mobile phase . The resolution of 4'-hydroxy flavanone enantiomers reached to 3.65 about 15 min. Compared with the native β-cyclodextrin and γ-cyclodextrin-bonded stationary phases in the literature, the separation speed of BZCDP containing mono - N -benzyl-phenethylamino-β-cyclodextrin ligand was faster and the separation selectivity was better, which indicated that the N -benzyl-phenethylamino group could also take part in the chiral recognition. After further study, we found that in polar organic solvent mode, the inclusion and hydrogen bonding were the main forces of chiral separations, and in reversed-phase mode, the inclusion and hydrophobic interaction are the main driving forces for chiral separations. Besides excellent chromatographic performance, the home-made cyclodextrin column with mesoporous SBA-15 as the matrix was much cheaper than commercial columns, and good permeability, which can reduce the cost of test and provide fast separation. BZCDP has a good prospect in chiral drug analysis.
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JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
·
2017
·
IF 2.603
Jingyi Zhang,Donghao Liu,Yi Shi,Chen Sun,Muchuan Niu,Ruya Wang,Fan Hu,Deli Xiao,Hua He
In this research, a novel insoluble sorbent based on cyclodextrin and rigid aromatic groups tetrafluoroacetonitrile was designed for dispersive insoluble solid-phase extraction (DSPE). Due to its high adsorption capacity, this obtained polymer was applied to separation and concentration of trace quinolones in wastewater before HPLC determination. Various parameters influencing the extraction performance were studied and optimized. A DSPE approach coupled with high performance liquid chromatography was developed for the determination of four quinolones in wastewater samples. The limit of quantitation of fleroxacin, ciprofloxacin, gatifloxacin, norfloxacin were 2.67, 3.17, 4.75, 5.50 ng mL −1 , respectively. The recoveries of four quinolones range from 96.43 to 103.3% with relative standard deviations less than 4.5%. These results demonstrated that the proposed approach based on CDP was efficient, low-cost for extraction of quinolones from wastewater.
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JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
·
2017
·
IF 2.603
Xiaona Zhang,Jiahua Niu,Xiaoting Zhang,Rui Xiao,Minghua Lu,Zongwei Cai
In this research, a modified Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method based on graphene oxide@SiO 2 (SiO 2 @GO) nanocomposite as adsorbent of dispersive solid-phase extraction (dSPE) combined with high performance liquid chromatography (HPLC) for the analysis of four plant hormones in different plants was established. The as-prepared SiO 2 @GO was characterized by scanning electron microscopy, transmission electron microscopy and infrared spectroscopy. The experimental conditions for dSPE, including the ratio of material to liquid, pH of sample, adsorption and desorption time, desorption temperature as well as desorption solution, were investigated. The detection limits for the analysis of indole-3-acetic acid, indole-3-butyric acid, 1-naphthylacetic acid and abscisic acid were achieved below 0.05 μg mL −1 . The established method was applied to the analysis of the plant hormones in fruits, vegetables and other food samples. The obtained results indicated that the method was sensitive, accurate, convenient and quick, which provided an alternative analytical approach for plant hormones in complex matrices.
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PHYTOCHEMICAL ANALYSIS
·
2024
·
IF 3
Jing Qiu,Jie Li,Si-yang Shang,Peng Zhou,Jing Leng
Introduction Huangma Tincture (HMT) is a Chinese patent medicine with a history of clinical use for more than 60 years, widely used for treating dermal chronic ulcer such as diabetic foot ulcer. However, the overall quality evaluation and control method of HMT has not yet been researched. Objective The aim of this study is to establish a comprehensive quality evaluation and control method for HMT based on high-performance liquid chromatography (HPLC) fingerprint, chemometrics, and multicomponent content determination. Methods Establishing chemical fingerprint of HMT and carrying out similarity analysis comprehensively reflect the consistency of the formulation in terms of chemical composition. Chemometrics analyses, including hierarchical cluster analysis (HCA), principal component analysis (PCA), and orthogonal partial least squares-discriminant analysis (OPLS-DA), were performed to identify components crucial to quality differences. The content of five potential bioactive ingredients (brucine, strychnine, jatrorrhizine, coptisine, and berberine hydrochloride) was determined as a supplementary quality control measure. Results HPLC fingerprint of HMT with similarity index > 0.990 was established, in which five common compounds (brucine, strychnine, jatrorrhizine, coptisine, and berberine hydrochloride) were identified. HCA, PCA, and OPLS-DA results, validated through 200 permutation tests, were basically consistent. The contents of brucine, strychnine, jatrorrhizine, coptisine, and berberine hydrochloride in 20 batches of HMT samples were 0.2088–0.5556, 0.2599–0.9868, 0.1358–0.2092, 0.2634–0.6843, and 1.8301–2.7826 mg/mL, respectively. Conclusion HPLC fingerprint combined with chemometrics and multicomponent content determination considering both effect and toxicity provides a robust method for the comprehensive quality evaluation and control of HMT.
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JOURNAL OF CHROMATOGRAPHY A
·
2024
·
IF 3.8
Wenhui Lu,Shanchao Fu,Xiuqi Lang,Huizhen Zhao,Deyi Zhu,Shan Cao,Lingxin Chen,Jinhua Li
Magnetic multi-template molecularly imprinted polymers (M-mt-MIPs) were successfully synthesized by surface imprinting and multi-template imprinting strategy, using polydopamine coated magnetic multi-walled carbon nanotubes as supporting materials, five typical chlorophenols (CPs) as templates, methacrylic acid as functional monomer and ethylene glycol dimethacrylate as cross-linker. Compared to non-imprinted polymers (NIPs), the as-prepared M-mt-MIPs showed high adsorption capacity (32.58‒80.63 mg g −1 ), rapid mass transfer and specific selectivity for the five targeted CPs, which were applied as magnetic solid-phase extraction (MSPE) adsorbents. Parameters affecting MSPE efficiency were detailed investigated, such as adsorbents dosage, sample pH, extraction time, type and volume of desorption solvent and salt effect. Combined with HPLC-DAD, a simple, rapid and sensitive method was established, showing good linearity (2‒200 μg L −1 ), low limits of detection (0.32‒0.49 μg L −1 ), and high enrichment factors (35.2‒108). The developed M-mt-MIPs-MSPE-HPLC method was applied to enrich and determine CPs in tannery wastewater, wet-blue and crust leather, and satisfactory spiking recoveries were attained in the range of 73.95‒109.7% with relative standard deviations (RSDs) of 2.13–8.48%. This study provided a new alternative material and method to rapid simultaneously extract and analyze low concentration of typical CPs in complicated matrices.
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JOURNAL OF FOOD BIOCHEMISTRY
·
2018
·Vol. 42
·期 3
·e12517
·
IF 1.552
Jiao-Jiao Yuan,Jun-Ling Tu,Frank G. F. Qin,Yong-Jun Xu,Bing Li
Oleuropein is an antioxidant olive constituent, but it is liable to degrade into hydroxytyrosol. Oleuropein extract was hydrolyzed by hemicellulase and the results presented that 14 phenols were identified in the ethyl acetate extract of enzymatic hydrolysate by HPLC-MS. Antioxidant activities (DPPH, ABTS, total reducing power, FRAP, and Fe 2+ chelating ability) of phenols were all added with the samples concentration increased, and dose–effect relationship also existed. 14 phenols all possessed certain inhibition effect against selected bacteria, and they had better inhibition effect against tested Gram-positive bacterium ( Staphylococcus aureus ) than Gram-negative bacterium ( Escherichia coli ). Finally, hydroxytyrosol, oleuropein, eugenol, caffeic acid, and 3,4-dihydroxybenzoic acid could present excellent antioxidant and antibacterial effect, and the two activities mainly had close relationship. Practical applications From the previous study we could know enzymatic biotransformation from oleuropein to HT was a promising method. Therefore, HT preparation from enzyme has attracted great attention of researcher. If that, a lot of enzymatic hydrolysate would be produced in the process. So, present study was to use fully the ethyl acetate extract of enzymatic hydrolysate, and to determine the chemical composition of phenolic compounds in EAE by HPLC-MS, and to evaluate their antioxidant and antimicrobial capacity. The result was shown that phenols of oleuropein extract after enzymatic process, therefore, may be suitable as a source of powerful antioxidants and bacteriostatic due to their stronger antioxidant and antibacterial activities. They could be widely applied in functional food industry for preservation.
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MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Yaqin Nan,Pingyi Zheng,Xiaoqian Yuan,Xinyu Xu,Xiao Zhang,Youxin Li
In this study, sulfopropyl ether β-cyclodextrin polymer (SPE-β-CDP) with simple synthesis steps using cheap reagents was large-scalely prepared. Characterization results showed the average sulfonic group substitution in each β-CD molecule was about 7.261, and there were 195.87 μmol/g β-CD units in polymer. It was low viscosity and produced a little effect on column pressure. It was used as chiral selectors first time to add into mobile phase to separate 13 chiral drugs in HPLC. After investigation, results showed buffer pH, chiral additive concentration, organic phase proportion in mobile phase and flow rate could affect chiral separation. High separation ability of SPE-β-CDP was proved through baseline separation of 12 drugs which attributed to the homogeneity of SPE-β-CDP in sulfonic acid group substitution degree and position. The resolutions of salbutamol, bisoprolol, chlorpheniramine, propranolol and metoprolol could be even up to 7.47–19.02, which were significantly better than that of some references. Separations of 4 chiral drugs were even better than that of CE. Compared with monomer, SPE-β-CDP showed better chiral separation ability. SPE-β-CDP could be used in both of C8 and C18 columns. It was stable in batches and showed good recyclability and reusability. These provided a new strategy for chiral separation.
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INDUSTRIAL CROPS AND PRODUCTS
·
2024
·
IF 5.6
Weikang Shen,Haobo Wang,Zhouzhe Lan,Guangzhi Xu,Qinxue Ni,Qiufen Mo,Youzuo Zhang,Yan Wang
Gardenia fruit oil (GFO) is a new emerging edible woody oil with few investigations of its’ refinement process. In this study, different degumming, deacidification and bleaching technologies were introduced for realizing moderate refining of the GFO based on the preservation of bioactive micronutrients. Firstly, a simple multi-stage solid phase extraction (SPE) combined with a lab- affordable HPLC-UV instrument was developed for determinations of several vital biological constituents, such as crocetin, geniposide, polyphenols, phytosterols and squalene in the GFO. Satisfactory limit of detection (LOD), limit of quantification (LOQ), recovery, intra-day and inter-day precision were obtained. Subsequently, changes of those phytochemicals during three types of degumming, followed by three kinds of deacidification and then three ways of bleaching were investigated, offering insightful suggestions for achieving moderate refining of the GFO. Finally, the refined GFO might be suggested as a potential functional edible oil with valuable micronutrients. To our knowledge, this is the first study investigating moderate refinement techniques for GFO, as well as developing novel methods for phytonutrients analysis in the GFO.
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