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 共查询到20条相似文献,搜索用时 31 毫秒
1.
Xiong  Xunyu  Zhang  Qunzheng  Xiong  Fengmei  Tang  Yuhai 《Chromatographia》2008,67(11):929-934

A simple and sensitive method was developed for the determination of three nonsteroidal anti-inflammatory drugs (NSAIDs)—ibuprofen, naproxen and fenbufen in human plasma. The method involved in column liquid chromatographic separation and chemilumenescence (CL) detection based on the CL reaction of NSAIDs, potassium permanganate (KMnO4) and sodium sulfite (Na2SO3) in sulfuric acid (H2SO4) medium. The chromatographic separation was carried out using a reversed-phase C18 column, which allowed the selective determination of the three medicines in the complicated samples. The special features of the CL detector provided lower LOD for determination than that of existing chromatographic alternatives. The results indicated that the linear ranges were 0.01–10.0 μg mL−1 for ibuprofen, 0.001–1.0 μg mL−1 for naproxen, and 0.01–10.0 μg mL−1 for fenbufen. The limits of detection were 0.5 ng mL−1 for ibuprofen, 0.05 ng mL−1 for naproxen and 0.5 ng mL−1 for fenbufen (S/N = 3). All average recoveries were in the range of 90.0–102.3%. Finally, the method had been satisfactorily applied for the determination of ibuprofen, naproxen and fenbufen in human plasma samples.

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2.
Dogan-Topal  B.  Ozkan  S. A.  Uslu  B. 《Chromatographia》2007,66(1):25-30

A rapid, sensitive, and specific reverse phase high performance liquid chromatography with diode array detection procedure for the simultaneous determination of abacavir, efavirenz and valganciclovir in spiked human serum is described. Separation was performed on a 5 μm Waters Spherisorb column (250 × 4.6 mm ID) with acetonitrile: methanol:KH2PO4 (at pH 5.00) (40:20:40 v/v/v) isocratic elution at a flow rate of 1.0 mL min−1. Calibration curves were constructed in the range of 50–30,000 ng mL−1 for abacavir and efavirenz, and 10–30,000 ngmL−1 for valganciclovir in serum samples. The limit of detection and limit of quantification concentrations of the HPLC method were 3.80 and 12.68 ng mL−1 for abacavir, 2.61 and 8.69 ng mL−1 for efavirenz, 1.30 and 4.32 ng mL−1 for valganciclovir. The method has been applied, without any interference from excipients or endogenous substances, for the simultaneous determination of these three compounds in human serum.

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3.
Chemiluminescence (CL) of an acidic KMnO4 system in the presence of Tween 80 was investigated for the determination of sulpiride. Strong CL was recorded when a mixture of sulpiride and Tween 80 was injected into acidic KMnO4 solution. The experimental parameters affecting the CL intensity were carefully studied using flow injection mode. Under the optimum conditions, the CL intensity was proportional to the concentration of sulpiride in the range of 5.0 × 10−7 ∼ 1.0 × 10−4 g mL−1. The detection limit is 1.6 × 10−7 g mL−1 sulpiride, and the relative standard deviation for 1.0 × 10−6 g mL−1 sulpiride solution is 1.5% (n = 11). The proposed method has been successfully applied to the determination of sulpiride in tablets and in spiked human plasma and urine samples.  相似文献   

4.
An effective electrochemical sensor was constructed using an unmodified boron-doped diamond electrode for determination of genistein by square-wave voltammetry. Cyclic voltammetric investigations of genistein with HClO4 solution indicated that irreversible behavior, adsorption-controlled and well-defined two oxidation peaks at about +0.92 (PA1) & +1.27 V (PA2). pH, as well as supporting electrolytes, are important in genistein oxidations. Quantification analyses of genistein were conducted using its two oxidation peaks. Using optimized experiments as well as instrumental conditions, the current response with genistein was proportionately linear in the concentrations range of 0.1 to 50.0 μg mL−1 (3.7×10−7−1.9×10−4 mol L−1), by the detection limit of 0.023 μg mL−1 (8.5×10−8 mol L−1) for PA1 and 0.028 μg mL−1 (1.1×10−7 mol L−1) for PA2 in 0.1 mol L−1 HClO4 solution (in the open circuit condition at 30 s accumulation time). Ultimately, the developed method was effectively applied to detect genistein in model human urine samples by using its second oxidation peak (PA2).  相似文献   

5.
A new and simple photoelectrochemical (PEC) sensor using a glassy carbon electrode (GCE) modified with bismuth vanadate (BiVO4) nanoparticles and dihexadecyl phosphate (DHP) film was useful for acetaminophen (AC) determination. In 0.2 mol L−1 phosphate buffer (pH=9), the GCE without modification exhibited the smaller photocurrent (0.86 μA) when compared with GCE modified with 1.0 mg mL−1 or 2.0 mg mL−1 BiVO4 nanoparticles suspension (5.9 and 34 μA, respectively). Based on the photocurrent signal generated through the interaction between GCE, BiVO4 and the energy of visible light a chronoamperometric method for AC determination was developed. The AC linear range concentration from 0.099 to 0.99 μmol L−1 and limits of detection and quantification of 0.027 and 0.091 μmol L−1, respectively, was obtained. The proposed method was applied to the AC determination in commercial drugs and tap water with satisfactory accuracy and precision. Moreover, the PEC construction was easy and had a short response time, which might confer higher sample throughput for the method.  相似文献   

6.
《Electroanalysis》2017,29(7):1691-1699
The simultaneous voltammetric determination of melatonin (MT) and pyridoxine (PY) has been carried out at a cathodically pretreated boron‐doped diamond electrode. By using cyclic voltammetry, a separation of the oxidation peak potentials of both compounds present in mixture was about 0.47 V in Britton‐Robinson buffer, pH 2. The results obtained by square‐wave voltammetry allowed a method to be developed for determination of MT and PY simultaneously in the ranges 1–100 μg mL−1 (4.3×10−6–4.3×10−4 mol L−1) and 10–175 μg mL−1 (4.9×10−5–8.5×10−4 mol L−1), with detection limits of 0.14 μg mL−1 (6.0×10−7 mol L−1) and 1.35 μg mL−1 (6.6×10−6 mol L−1), respectively. The proposed method was successfully to the dietary supplements samples containing these compounds for health‐caring purposes.  相似文献   

7.
Ate&#;  Z.  &#;zden  T.  &#;zilhan  S.  Toptan  S. 《Chromatographia》2007,66(1):123-127

A simple method for the determination of carbamazepine and its active metabolite carbamazepine-10,11-epoxide by ultra performance liquid chromatography (UPLC) with ultraviolet absorbance detection (TUV) was developed. The method involves a two-step protein precipitation by liquid–liquid extraction. Phenytoin sodium was used as the internal standard. The separation was carried out on Acquity C18 column with acetonitrile:methanol:KH2PO4 buffer (adjusting pH to 4.6 with 85% o-phosphoric acid) (180/180/170, v/v/v) as the mobile phase at a flow rate of 0.4 mL min−1. Linear detection response was obtained for concentrations ranging from 50 to 5,000 ng mL−1. The limit of quantification (LOQ) was 50 ng mL−1. The method was validated successfully for the determination of carbamazepine and its active metabolite carbamazepine-10,11-epoxide, which can be applied through pharmacokinetics and bioequivalence studies.

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8.
A simple sensitive LC–MS/MS method has been developed for the simultaneous determination of giraldoid A and giraldoid B in rat plasma. The method was applied to pharmacokinetics studies of the two compounds from Daphne giraldii Nitsche. Chromatographic separation was accomplished on an Acquity UPLC™ BEH C18 column (100 × 2.1 mm, 1.7 mm) by gradient elution with a flow rate of 0.2 mL min−1. The method was linear over the concentration range of 1.0–1000 ng mL−1, and the lower limits of quantification were 1.04 ± 0.10 and 1.04 ± 0.09 ng mL−1, respectively. The intra‐ and inter‐day precisions (RSD) were <10.14 and 9.96%. The extraction recovery of the analytes was acceptable. Stability studies demonstrated that the two compounds were stable in the preparation and analytical process. The maximum plasma concentration was 687.78 ± 243.62 ng mL−1 for giraldoid A and 952.38 ± 131.99 ng mL−1 for giraldoid B. The time to reach the maximum plasma concentration was 0.50 ± 0.37 h for giraldoid A and 0.50 ± 0.66 h for giraldoid B. The validated method was successfully applied to investigate the concentration–time profiles of giraldoid A and giraldoid B.  相似文献   

9.
Electrochemical biosensors have made outstanding achievements in recent years. However, the single pursuit of sensitivity and accuracy sometimes cannot meet the detection requirements and achieve high-efficiency measurements. Therefore, no-washing biosensors have more practical advantages. In this work, a disposable point-of-care (POC) electrochemical biosensor was designed for the sensitive and fast detection of neuron-specific enolase (NSE). Fe3O4 and CuS nanoparticles were used as the substrate material for capturing Ab1 and the signal probe for labeling Ab2 respectively. The disposable syringe filter was introduced into the determination procedure for simple sample separation, which easily realized no-washing detection. Due to the syringe filters with 200 nm pore diameter could only allow the small nanoparticles of CuS−Ab2 pass through, the large-sized immunocomplex of Fe3O4−Ab1/NSE/CuS−Ab2 were blocked on the membrane. The uncombined CuS−Ab2 particles were pushed out from the syringe and would occur electron transfer between Cu2+ and Cu+ to generate a current signal detected by the Au electrode. Under optimal conditions, the no-washing biosensor shows a wide linear concentration range (100 fg mL−1∼50 ng mL−1) with the limit of detection of 33 fg mL−1 (S/N=3). Additionally, the biosensor exhibited excellent selectivity, storage stability and reproducibility. The outstanding advantages of the no-washing biosensor make it more suitable for POC testing.  相似文献   

10.
A method for the simultaneous determination of aluminum (Al), cadmium (Cd) and lead (Pb) in whole blood has been developed by using simultaneous atomic absorption spectrometry (SIMAAS) with oxygen charring. The optimized conditions for the simultaneous determination of Al, Cd and Pb were obtained in the presence of palladium (Pd) as the chemical modifier, using 600 °C and 2400 °C as the pyrolysis and the atomization temperature, respectively. The whole blood samples were diluted 1+5 (v/v) directly with 0.1% (v/v) Triton X‐100. Oxygen was employed to eliminate the interference of carbonaceous residues in the charring step before pyrolysis. The calibration curves were carried out with aqueous standard solutions and the linear ranges were 0–40 ng mL−1, 0–4 ng mL−1 and 0–40 ng mL−1 for Al, Cd and Pb, respectively. The detection limits were 0.96 ng mL−1 (19.2 pg) for Al, 0.03 ng mL−1 (0.6 pg) for Cd and 0.60 ng mL−1 (12.0 pg) for Pb. The spiked recoveries of Al, Cd and Pb in whole blood were 98.0%, 100.0% and 101.7%, respectively. The accuracy of the proposed method was evaluated with the analysis of a whole blood certified reference material (Seronorm, level 2). The found concentrations were in agreement with the recommended values. The proposed method has been successfully applied to the simultaneous determination of Al, Cd and Pb in whole blood of healthy volunteers before and after eating barbecued foods.  相似文献   

11.

A simple, reproducible, and efficient liquid chromatographic method was developed with UV detection. Water (0.05% TFA):acetonitrile (0.05% TFA) was used as the mobile phase in a gradient system for the determination of procyanidin B2 (PB2) and epicatechin (EC) in the bark of Guazuma ulmifolia Lam. The analysis was performed using a Phenomenex Gemini RP C18 column (5 μm) as stationary phase, at 30 °C, with a flow rate of 0.8 mL min−1, at a wavelength of 210 nm for detection and determination. The main validation parameters of the method were also determined. Calibration curves were found to be linear, with ranges of 20.00–150.00 (PB2) and 10.00–110.00 μg mL−1 (EC). The correlation coefficients of linear regression analysis were between 0.9981 and 0.9988, and the detection limits were between 2.89 and 2.54 μg mL−1. The contents of PB2 and EC were successfully determined, with satisfactory reproducibility and recovery. Recoveries of the PB2 and EC were 103.00 and 104.01%, respectively. The method was successfully applied to the determination of procyanidins in the bark of G. ulmifolia.

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12.
《Electroanalysis》2017,29(3):835-842
A novel electrochemically activated doped Ta2O5 particles modified carbon paste electrode (EA‐Ta2O5‐CPE) was prepared and applied for selective and sensitive determination of chrysin. X‐ray diffraction (XRD), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) techniques and cyclic voltammetry (CV) were used to characterize the Ta2O5 particles and investigate the electrochemical response of the sensor. Compared with bare CPE, the doped Ta2O5 modified electrode got much more porous by electrochemical treatment and exhibited larger effective surface area, more reactive site and excellent electrochemical catalytic activity toward the oxidation of chrysin. Under optimum conditions by LSV, the oxidation peak currents responded to chrysin linearly over a concentration range from 5.0×10−8 to 7.0×10−6 mol L−1 with a detection limit of 2.0×10−8 mol L−1 (5.08 ng mL−1). The fabricated sensor showed anti‐interference ability against the biological common interferents (i.e. baicalein, baicalin) and provided to be reliable for the determination of chrysin in Chinese medicinal herb Oroxylum indicum and chrysin capsules samples with satisfactory results.  相似文献   

13.

A new, sensitive and stability indicating liquid chromatographic method has been developed for the determination of imatinib mesylate (IM). Efficient chromatographic separation was achieved using a C18 column with simple mobile phase combination delivered in an isocratic mode and quantitation was carried out using ultraviolet detection. For the first time, a novel microwave assisted degradation procedure was employed for stress testing studies. In addition, orthogonal separation technique was applied to demonstrate selectivity of the proposed method. The method has demonstrated excellent linearity over the range of 25–1,600 ng mL−1. Moreover, the method was found to be sensitive with a low limit of detection (3.35 ng mL−1) and limit of quantitation (10.16 ng mL−1). The method has shown good and consistent recoveries (99.35–100.69%) with low intra- and inter-day relative standard deviation (RSD) (<2.5%). Experimental design confirmed that peak area was unaffected by small changes in critical factors, in robustness study. The validated method was successfully applied for determination of IM in pharmaceutical formulations.

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14.
A novel and sensitive method for the determination of aflatoxin B1 (AFA−B1) in ground paprika using a methyltrioctylammonium chloride ionic liquid (IL), iron oxide nanorods (Fe3O4 nanorods) and reduced graphene oxide (RGO) fabricated glassy carbon electrode (GCE) was developed. The synthesized nanoparticles, nanocomposites and modified electrode surfaces were characterized by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), thermogravimetric analysis (TGA/DSC) and x-ray diffraction (XRD) analyses. Moreover, the electrochemical performance of the developed sensor was determined by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The obtained results demonstrate that the sensitivity of AFA−B1 is significantly enhanced on RGO-Fe3O4 nanorods-IL-GCE in comparison with bare GCE, RGO-GCE and RGO-Fe3O4 nanorods-GCE. The redox peak currents of AFA−B1 exhibited good linear relationship with its concentration in the range from 0.02 to 0.33 ng mL−1 with detection limit of (LOD) 0.03 ng mL−1 and limit of quantification (LOQ) 0.36 ng mL−1 respectively (S/N=3). In addition, the fabricated electrode showed good stability and reproducibility. The proposed technique was effectively applied to identify the AFA−B1 in real ground paprika samples with acceptable results.  相似文献   

15.
A new, simple-to-synthesize and sensitive turn-on fluorogenic substrate ( CFMU-Glu ) for β-glucosidase activity was developed. This probe was based on a 7-hydroxycoumarin derivative ( CFMU ) that could emit green fluorescence and had the low pKa value of 5.61 ± 0.01. CFMU-Glu could be used for sensitive monitoring of the almond βGLU and Enterococcus faecalis (E. faecalis) at the optimal pHs of 6.50 and 7.00, respectively. Moreover, a new sensitive and selective fluorogenic broth (PBF-B) for E. faecalis, utilizing CFMU-Glu and polymyxin B, was also developed. Polymyxin B was discovered to can significantly improve the detection selectivity and signal intensity. The proposed 4-four method using PBF-B and a microcentrifuge tube could provide fluorogenic detection limits of 5.01 × 104 and 1.0 × 105 CFU mL−1 by fluorescence microplate reader and naked eye, respectively; it could also provide a turn-on chromogenic detection limit of 1.0 × 106 CFU mL−1 by naked eye. The proposed method could detect 8 CFU mL−1 of E. faecalis in drinking water, Liangcha (herbal tea) and milk samples within 10 h, without pre-enrichment.  相似文献   

16.
《Electroanalysis》2017,29(12):2818-2831
Immobilization of biomolecules with a proper orientation is considered as a basis for diverse biotechnological applications. Herein, we report a host‐guest inclusion complexation between β‐cyclodextrin (β‐CD) and biotin as a versatile approach for the immobilization of biomolecules. As a practical application, a sandwich‐type electrochemical immunosensor was designed for the determination of prostate specific antigen (PSA). The immunosensor was fabricated by in situ electropolymerization of poly(N‐acetylaniline) onto a rGO‐modified Pt electrode. Then, β‐CD was covalently grafted onto the over‐oxidized polymer backbone. For improving the efficiency of the assay, AuNPs were casted on the polymeric film, on the surface of which thionine (TH) as an electron mediator was covalently immobilized. Using a host‐guest inclusion complexation between β‐CD and biotin, a β‐CD/biotin‐Ab1/PSA/Ab2‐horseradish peroxidase (HRP) sandwich was formed on the electrode surface. The analytical signal was produced via electrochemical reduction of THox, generated by biocatalytic oxidation of the THred in the presence of HRP/H2O2. Under optimal conditions, the proposed sensor responded linearly to PSA in the range from 10.0 pg mL−1 to 25.0 ng mL−1, with a low detection limit of 6.7 pg mL−1 (S/N=3). Kinetic parameters of the interaction of β‐CD with Ab1 were also investigated. Finally, the applicability of the immunosensor was successfully investigated for the detection of PSA in human serum samples.  相似文献   

17.
Determination of estrogens in water by HPLC-UV using cloud point extraction   总被引:1,自引:0,他引:1  
Wang L  Cai YQ  He B  Yuan CG  Shen DZ  Shao J  Jiang GB 《Talanta》2006,70(1):47-51
A method based on cloud point extraction was developed to determine four kinds of estrogens: estriol (E3), estradiol (E2), estrone (E1), and progesterone (P) in water by high performance liquid chromatography separation and ultraviolet detection (HPLC-UV). The non-ionic surfactant Triton X-114 was chosen as extractant solvent. The parameters affecting extraction efficiency, such as concentrations of Triton X-114 and Na2SO4, equilibration temperature, equilibration time and centrifugation time were evaluated and optimized. Under the optimum conditions, preconcentration factors of 99 for E3, 73 for E2, 152 for E1 and 86 for P were obtained for 10 mL water sample. The detection of limitation was 0.23 ng mL−1 for E3, 0.32 ng mL−1 for E2, 0.25 ng mL−1 for E1 and 5.0 ng mL−1 for P. The proposed method was successfully applied to the determination of trace amount of estrogens in wastewater treatment plant (WWTP) effluent water and exposure water with 10 ng mL−1 E2 for toxicological study in our lab. For the case of WWTP effluent water samples, no estrogen was found. The accuracy of the proposed method was tested by recovery measurements of spiked samples and good recoveries of 81.2-99.5% were obtained.  相似文献   

18.
Guo  Xiaorui  Chen  Xiaohui  Cheng  Weiming  Yang  Kaiyu  Ma  Yongfen  Bi  Kaishun 《Chromatographia》2008,67(11):1007-1011

A sensitive, simple, and accurate method for determination and pharmacokinetic study of ferulic acid and isoferulic acid in rat plasma was developed using a reversed-phase column liquid chromatographic (RP-LC) method with UV detection. Sample preparations were carried out by protein precipitation with the addition of methanol, followed by evaporation to dryness. The resultant residue was then reconstituted in mobile phase and injected into a Kromasil C18 column (250 × 4.6 mm i.d. with 5 μm particle size). The mobile phase was methanol-1% formic acid (33:67, v/v). The calibration plots were linear over the range 5.780–5780 ng·mL−1 for ferulic acid and 1.740–348.0 ng·mL−1 for isoferulic acid. Mean recoveries were 85.1% and 91.1%, respectively. The relative standard deviations (RSDs) of within-day and between-day precision were not above 15% for both of the analytes. The limits of quantification were 5.780 ng·mL−1 for ferulic acid and 1.740 ng·mL−1 for isoferulic acid. This RP-LC method was used successfully in pharmacokinetic studies of ferulic acid and isoferulic acid in rat plasma after intravenous injection of Guanxinning Lyophilizer.

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19.
The COVID-19 pandemic is still a continuing worldwide challenge for public health systems. Early and ultrasensitive identification of the infection is essential for preventing the spread of COVID-19 by pre-symptomatic or asymptomatic individuals, particularly in the community and in-home settings. This work presents a versatile photoelectrochemical (PEC) immunosensor for SARS-CoV-2 detection based on a composite material formed by bismuth vanadate (BiVO4) and strontium titanate (SrTiO3). The PEC platform was denoted as BiVO4/SrTiO3/FTO, and it can be tuned for the detection of either Spike (S) or Nucleocapsid (N) protein by simply altering the antibody immobilized on the platform's surface. Chemical, morphological, and electrochemical characterizations were performed by X-Ray Diffraction, Scanning Electron microscopy, Energy-dispersive X-ray spectroscopy, Electrochemical Impedance Spectroscopy, and Amperometry. With a simple sensing architecture of the PEC platform, it was possible to achieve a linear response range of 0.1 pg mL−1 to 1000 ng mL−1 for S protein and 0.01 pg mL−1 to 1000 ng mL−1 for N protein. The PEC immunosensors presented recovery values for the two SARS-CoV-2 proteins in artificial saliva samples between 97 % and 107.20 % suggesting a good accuracy for the proposed immunosensors.  相似文献   

20.
Jing Wang  Wen Meng  Zhenjie Ni  Sijia Xue 《中国化学》2011,29(10):2109-2113
A series of novel N‐(substituted benzyl)‐3,5‐bis(benzylidene)‐4‐piperidones 5a – 5o were synthesized with substituted benzylamines as raw materials via a series of Michael addition, Dieckmann condensation, hydrolysis decarboxylation and aldol condensation. The structures were confirmed by 1H NMR, IR, MS techniques and elemental analysis. Assay‐based antiproliferative activity study using leukemic cell lines K562 revealed that most of the title compounds have high effectiveness in inhibiting leukemia K562 cells proliferation, among which the compounds 5g (IC50=7.81 µg·mL−1), 5k (IC50=6.35 µg·mL−1), 5l (IC50=7.20 µg·mL−1), and 5o (IC50=5.79 µg·mL−1) have better inhibition activities than standard 5‐fluorouracil (IC50=8.56 µg·mL−1).  相似文献   

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