TALANTA
·
2019
·
IF 4.916
Xiao-Dong Sun,Hai-Long Wu,Zhi Liu,Yue Chen,Jun-Chen Chen,Li Cheng,Yu-Jie Ding,Ru-Qin Yu
Chemometrics multivariate calibration coupled with high performance liquid chromatography-diode array detection (HPLC-DAD) analytical strategy was applied for fast and sensitive quantification of the eight small molecules (uric acid, creatinine, tyrosine, homovanillic acid , hippuric acid, indole-3-acetic acid, tryptophan and 2-methylhippuric acid) in human urine. The objective of this work was to get the successful resolution of the complex matrix with minimum experimental time in the presence of highly overlapping peaks, of distortions in the time and baseline aspects among chromatograms, and of the presence of unknown and background interferences. All the analysis were based on a short C18 column with the chromatographic system operating in isocratic mode and all analytes can be successfully quantified within 6 min. The second-order HPLC-DAD data acquired were handled intelligently by two typical chemometrics tools including alternating trilinear decomposition (ATLD) and multivariate curve resolution-alternating least squares (MCR-ALS). Reasonable resolution and satisfactory quantification results were obtained regardless of the complex matrix interferences from the urine samples and the second-order advantage was fully exploited. With the validation by classic HPLC method, the proposed strategy could take extra advantages such as increased selectivity and sensitivity, shorter analysis time, undemanding elution conditions and sufficiency of lower limit of quantification benefit from multivariate calibration. The method was shown as a promising means for fast and sensitive determination of small molecules in human urine and also for fast diagnosis or surveillance in related diseases.
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高影响因子
ANALYTICA CHIMICA ACTA
·
2019
·
IF 5.256
Shiwei Yang,Danyu Zhang,Heyong Cheng,Yuanchao Wang,Jinhua Liu
For the past several decades, lots of adsorbent nanomaterials have been adopted for the enrichment of mercuric compounds. In this paper, graphene oxide bounded silica particles were employed as the absorbent for online preconcentration of Hg(II), methylmercury (MeHg) and ethylmercury (EtHg) by solid phase extraction . The adsorbent offered satisfactory adsorption capacities of 40.7 for Hg(II), 91.4 for MeHg and 103.8 mg g −1 for EtHg. Enrichment conditions such as type, concentration and volume of conditioning and eluting reagents were optimized. The pH, volume and flow rate of sample were also optimized. High enrichment factors (1963, 1881 and 1794 for Hg(II), MeHg and EtHg, respectively) were obtained with 10 mL sample (adjusted to pH 4–7) at 10 mL min −1 flow rate, 5 μL of 10 mM benzoic acid for elution and 4 mL of 1 mM 4-phenyl-3-aminothiourea for preconditioning. The detection limits obtained were downscaled to be 0.005 for Hg(II), 0.006 for MeHg and 0.009 ng L −1 for EtHg with relative standard deviations of all the analytes below 5%. Standard reference material and spiked water samples were analyzed for validating the method with satisfactory recoveries of 89–106%. The present method was successfully applied to determine mercury compounds in drinking water , and river and tap water , in which Hg(II), MeHg and EtHg were presented below the China's drinking standard limit of 1 μg L −1 .
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高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2019
·Vol. 42
·期 18
·2957-2967
·
IF 2.516
Xintong Jia,Xiaoyue Yang,Wei Zhao,Yuanan Hu,Hefa Cheng
Driven by the significant need for characterization of the chemical speciation of arsenic in food, this work developed a method for rapid determination of four common arsenic species, namely, arsenite, arsenate, monomethyl arsenic acid, and dimethyl arsenic acid, in vegetables using microwave-assisted extraction, followed by detection with high-performance liquid chromatography hyphenated to inductively coupled plasma-mass spectrometry. Initial screening results showed that microwave-assisted extraction using 1% HNO 3 exhibited the highest overall efficiencies for all arsenic species without causing significant degradation of the organic ones. With the aid of response surface methodology, the optimum conditions established for extraction of arsenic species from vegetables were: 500 mg of freeze-dried vegetable sample, extracted by closed vessel microwave-assisted extraction using 10 mL of 2% v/v HNO 3 at 90°C for 17 min. Application of the method in the analysis of 24 market vegetable samples indicates that the extraction efficiencies for total arsenic species were in the range of 91.4–106%. Arsenite and arsenate were found to be the predominant arsenic species in the vegetables, which suggests that vegetable consumption could be an important route of inorganic arsenic exposure for the population with a heavy vegetable diet in arsenic polluted regions.
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高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 11
·1-8
·
IF 5.479
Jiang Yanxiao,Ma Pinyi,Piao Huilan,Qin Zucheng,Tao Shuo,Sun Ying,Wang Xinghua,Song Daqian
Cellulose paper was coated with the metal-organic framework MIL-101(Cr) in a chitosan matrix and utilized for thin-film microextraction (TFME). The coated paper possesses excellent extraction efficiency for the triazine herbicides atraton, desmetryn, secbumeton, prometon, ametryn, dipropetryn, and dimethametryn. High-performance liquid chromatography-tandem mass spectrometry was applied to quantify target analytes. The effects of mass ratio of MIL-101(Cr) to chitosan, sample pH value, time of adsorption and desorption, and type and volume of desorption solvent on extraction efficiency were optimized. Under the optimal conditions, the method has limits of detection between 1.5 and 22 ng·L −1 . The recoveries of triazines from spiked tap water, drinking water, lake water and river water range from 77.0 to 125.3%, with relative standard deviations of <17.4%.
Cellulose paper was modified with metal-organic framework MIL-101(Cr)/chitosan by using a simple, efficient and environmentally friendly approach. The modified cellulose paper was then used as a novel extraction phase in thin-film microextraction (TFME).
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JOURNAL OF THE BRAZILIAN CHEMICAL SOCIETY
·
2018
·Vol. 29
·期 4
·757-765
·
IF 1.444
Li Xiaolan,Meng Dongling,Liu Ruiqi,Yang Yaling
A novel extraction technique combining dispersive liquid-liquid microextraction (DLLME) with magnetic solid-phase extraction (MSPE) is presented for pre-concentration of four primary aromatic amines (PAAs) released from azo dyes in paper samples prior to high performance liquid chromatography (HPLC). n-Octanol was used as the extractant and hydrophobic oleic acid modified Fe3O4 nanoparticles (Fe3O4@OA NPs) as an efficient adsorbent was applied to retrieve the PAAs-containing n-octanol in the DLLME step. Because of the rapid mass transfer associated with the DLLME and MSPE steps, fast extraction could be achieved. The main parameters affecting the efficiency of MSPE-DLLME procedure of PAAs were investigated and optimized. Under optimum conditions, the recoveries ranged from 79.6 to 88.5% and the limits of detection (LODs) were in the range of 0.21-1.16 ng mL-1 (S / N = 3). The intra-day precision (relative standard deviation (RSD)) was below 7.8% and inter-day RSD was less than 11%.
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TALANTA
·
2013
·
IF 3.498
Weina Wang,Ruiyang Ma,Qiuhua Wu,Chun Wang,Zhi Wang
In this study, a magnetic microsphere-confined graphene (Fe 3 O 4 @SiO 2 -G) was prepared as a novel adsorbent for the preconcentration of some phthalate esters in environmental water and soybean milk samples prior to high performance liquid chromatography analysis. The properties and morphology of the Fe 3 O 4 @SiO 2 -G were characterized by transmission electron microscopy and X-ray diffraction. This novel graphene-based magnetic nanocomposite showed great adsorptive ability toward the analytes. The method, which takes the advantages of both the high adsorption capacity of G and easy phase separation of the magnetic adsorbent from the sample solution, could avoid the time-consuming experimental procedures related to the traditional solid phase extraction . Various experimental parameters that could affect the extraction efficiencies, such as the amount of Fe 3 O 4 @SiO 2 -G, the extraction time, the pH of sample solution and the desorption conditions, were investigated. Under the optimum conditions, the limits of detection ( S / N =3) of the method for the compounds were between 0.07 and 0.10 ng mL −1 in water samples, and between 0.15 and 0.30 ng mL −1 in soybean milk samples. The relative standard deviations (RSDs) varied from 2.7% to 6.1% ( n =5). The recoveries of the method were in the range between 87.2% and 109.0% for environmental water and soybean milk samples. The method is suitable to determine the five phthalate esters (diallyl phthalate, di- n -propyl-phthalate, benzyl butyl phthalate, dicyclohexyl-phthalate and diethyl-hexyl-phthalate) in environmental water and soybean milk samples.
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JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
·
2014
·
IF 2.829
Guo Ma,Jiayuan Lin,Weimin Cai,Bo Tan,Xiaoqiang Xiang,Ying Zhang,Peng Zhang
Bilirubin, an important endogenous substances and liver function index in humans, is primarily eliminated via UGT1A1-catalyzed glucuronidation. Instability of bilirubin and its glucuronides brings substantial technical challenges to conduct in vitro bilirubin glucuronidation assay. In the present study, we developed a simple and robust HPLC method for simultaneous determination of unconjugated bilirubin (UCB) and its multiple glucuronides, i.e. bilirubin monoglucuronides (BMGs, including BMG1 and BMG2 isomers) and diglucuronide (BDG) in rat liver microsomes (RLM), human liver microsomes (HLM) and recombinant human UGT1A1 enzyme (UGT1A1) incubation systems, and applied it to study in vitro bilirubin glucuronidation. UCB, BMG1, BMG2, BDG and their isomers in the incubation mixtures were successfully separated using a C18 column with UV detection at 450 nm and mobile phase consisted of 0.1% formic acid in water and acetonitrile by a linear gradient elution program. Assay linearities of bilirubin were confirmed in the range 0.01–2 μM. Precision of UCB, BMG1, BMG2 and BDG ( n = 5) at low, medium and high concentration was within the range of RSD 0.4–3.7%, accuracy expressed in the mean assay recoveries of them ( n = 5) ranged from 92.8 ± 1.5% to 104.3 ± 2.2% for intra- and inter-day assays and the mean extraction recoveries of them ( n = 5) were above 91.5 ± 1.0%. Stability of bilirubin and its glucuronides was satisfactory at 37 °C in the incubation solutions during the reaction (30 min), 25 °C for 24 h and −70 °C for 7 d in the processed incubation samples with methanol. Furthermore, we established stable, reliable in vitro incubation systems and optimized the incubation conditions to characterize the kinetics of bilirubin glucuronidation by RLM, HLM and UGT1A1, respectively. The kinetic parameters of formation of total bilirubin glucuronides (TBG, the sum of BMG1, BMG2 and BDG) were as follows: K m of 0.45 ± 0.016, 0.40 ± 0.022, 0.44 ± 0.018 μM, V max of 2.65 ± 0.057, 1.86 ± 0.029, 2.95 ± 0.036 nmol/mg/min, CL int of 5.92 ± 0.22, 4.70 ± 0.079, 6.72 ± 0.27 mL/mg/min by RLM, HLM and UGT1A1, respectively. Bilirubin glucuronidation obeyed the Hill equation by RLM and the Michaelis–Menten equation by HLM and UGT1A1 in the range of substrate concentration selected, respectively. In addition, the relative proportions between BDG and BMGs were in connection with enzyme sources (e.g. RLM, HLM and UGT1A1) and bilirubin concentration.
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Analytical Methods
·
2014
·Vol. 6
·期 13
·4845-4852
·
IF 1.938
Qi Yun,Qingwang Liu,Cunyong He,Xiaohua Ma,Xiaoli Gao,Amer Talbi,Jianping Zhou
Nigella glandulifera Freyn et Sint seeds (NG) as well as Nigella sativa L. seeds (NS) have been employed as folk remedies for centuries. However, little work has been done on their quality control. In order to assess the quality and guarantee therapeutic effects, the chemical constituents of the two herbs were extensively characterized by ultra-performance liquid chromatography coupled with electrospray time-of-flight mass spectrometry (UPLC-Q-TOF/MS), and a simple, practical, and reliable HPLC fingerprinting method was established and applied to determination of 20 batches of samples. With their chromatographic fingerprints, the two species were successfully differentiated by pattern recognition methods, namely, principal component analysis (PCA) and partial least square discriminant analysis (PLS-DA). Results from this study show that the proposed analytical methods can be applied to the quality control of the seeds and have high potential to ensure their safety and efficacy.
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JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
·
2016
·
IF 2.687
Xia Wu,Han Cao,Lifang Zhao,Jianao Song,Yuqi She,Yifan Feng
Non-destructive proton nuclear magnetic resonance ( 1 H NMR) spectroscopy and highly sensitive ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (U-HPLC/Q-TOF-MS) coupled to data processing methods were applied to analyze the metabolic profiling changes of glycerophospholipids (GPLs) in RAW264.7 cells from inflammation to prognosis. Analysis of 1 H NMR was shown that the models were grouped successfully, illustrating that all of them had significant differences. Based on the highly simple, accurate, non-targeted and non-destructively advantages of 1 H NMR, it could be used as a new screening tool of anti-inflammatory drugs in the metabolic profiling of GPLs. 58 GPLs were identified by U-HPLC/Q-TOF-MS, and 19 components were firstly identified in this study compared with our previous results. In addition, ten potential biomarkers were proved, of which phosphatidylcholine (PC) (16:0/18:1) and (18:0/18:1) changed consistently in three drug-induced groups and might be the important biomarkers. Compared with 1 H NMR, U-HPLC/Q-TOF-MS showed higher sensitivity and specificity and was more suitable for the determination of biomarkers apart from the deficiency of time-consuming sample preparation steps and unambiguous metabolite identification. Therefore, it is feasible to analyze the changes of GPLs during inflammation by combining 1 H NMR spectroscopy with U-HPLC/Q-TOF-MS. The metabolic profiling of GPLs provides valuable evidence for inflammation diagnosis and prognosis, and might unravel the mechanisms involved in inflammation progression.
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高影响因子
CHROMATOGRAPHIA
·
2012
·Vol. 75
·期 15
·883-892
·
IF 1.195
Zhou Wei,Zhang Yanhai,Ning Suli,Li Yan,Ye Mingli,Yu Yingjia,Duan Gengli
Automated on-line SPE/multi-stage column-switching and benzoic acid-based quantitative analysis of multi-components by single-marker/respective optimal detection wavelengths-high performance liquid chromatography (QAMS/RODWs-HPLC) as a novel analysis model was reported in the study; it obtained simple, effective, very low-cost, sensitive and reliable characteristics. This method has been set up for direct analysis of syringic acid, benzoic acid, and salicylic acid in rat plasma, and its application to the pharmacokinetic study of syringic acid and salicylic acid in rats. The chromatographic separation was performed on two C18 columns with the elution of methanol and 0.5 % formic acid aqueous solution in two pump systems, detection wavelengths of 230, 236, and 275 nm, 500-μL injection volume. Their linear ranges were between 0.008 and 166.7 μg mL −1 with correlation coefficient of 0.9977–0.9997. Benzoic acid-based QAMS/RODWs-HPLC was also compared with other two quantitative analysis methods (external standard method of RODWs-HPLC, internal standard method of RODWs-HPLC) based on pharmacokinetic data; the similarities of three analytical methods in accordance with separately obtained concentrations of syringic acid and salicylic acid in rats were 0.9997–0.9999 by the cosine value method of vectorial angle. The pharmacokinetics of syringic acid and salicylic acid were simultaneously studied in SD rats following 30 mg kg −1 intragastric administration, and their pharmacokinetic parameters were also estimated. This method was successfully applied to determination of syringic acid and salicylic acid in rat plasma samples and their oral pharmacokinetics in rats.
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RESEARCH ON CHEMICAL INTERMEDIATES
·
2012
·Vol. 38
·期 9
·2237-2243
·
IF 0.697
Zhou Minghao,Xiao Guomin,Hong Mei
(6R)- and (6S)-5,6,7,8-tetrahydrofolic acid were resolved by reversed-phase HPLC on a C-18 column with hydroxypropyl-β-cyclodextrin (HP-β-CD) in the mobile phase. As the concentration of HP-β-CD increased from 0 to 45 mM, resolution increased and retention times decreased dramatically. The influence of different mobile phase pH, column temperature, and some other factors were evaluated, and we obtained the optimal HPLC separation conditions.
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NEW JOURNAL OF CHEMISTRY
·
2024
·Vol. 48
·期 21
·9702-9708
·
IF 2.7
An-Xu Ma,Cai-Fang Liu,Yu-Lan Zhu,Zong-Hong Luo,Hong-Mei Zhou,Yue Zhang,Bang-Jin Wang,Jun-Hui Zhang,Sheng-Ming Xie,Li-Ming Yuan
In this work, a chiral core–shell microspheres composite, L-his-MIL-53-NH2@SiO2, was prepared through in situ growth and chiral post-modification strategies. The core–shell microspheres were applied as a novel chiral stationary phase for HPLC enantiomeric separation. Various racemates were separated on the L-his-MIL-53-NH2@SiO2 packed column using n-hexane/isopropanol as the mobile phase. The chiral column showed excellent separation efficiency for fourteen chiral compounds, including alcohols, alkanes, esters, phenols, ketones, and organic acids. The influence of injection mass and temperature on the separation performance of the chiral column were investigated. The relative standard deviations (n = 5) of the retention time and peak area by repeated separation of benzoin are 0.28% and 0.63%, respectively. The results show that the L-his-MIL-53-NH2@SiO2 packed column exhibited good reproducibility and stability. In addition, the chiral resolution ability of the L-his-MIL-53-NH2@SiO2 packed column was compared with that of a commercial chiral column (Chiralpak AD-H). The L-his-MIL-53-NH2@SiO2 packed column exhibits unique advantages in chiral separations that can be complementary to the commercial chiral column. It was demonstrated that the chiral core–shell microspheres composite L-his-MIL-53-NH2@SiO2 prepared based on in situ growth and chiral post-modification strategies has great potential for enantiomeric separation by HPLC.
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