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1.
Chemosphere ; 292: 133345, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34922964

RESUMO

Zero waste multistage utilization of biomass from Ginkgo biloba branches (GBBs) was achieved through extraction of bioactive components, analysis of antioxidant and antibacterial activities, preparation and composition of pyrolyzate, adsorption and reuse of modified biochar. The results showed that GBBs had abundant bioactive components for potential application in the industry of food, chemical raw materials and biomedicine. Especially, the bioactive compounds in acetone extract (10 mg/mL) of GBBs identified by DPPH and ABTS had free radical scavenging abilities of 92.28% and 98.18%, respectively, which are equivalent to Vitamin C used as an antioxidant in food additives. Fourier Transform Infrared and X-Ray Diffraction analysis showed that carboxymethyl cellulose (CMC) and magnetic Fe3O4 were successfully incorporated into raw biochar (RB) to form CMC-Fe3O4-RB nanomaterial. Scanning electron microscopy and X-Ray Diffraction spectroscopy displayed Fe, C, and O existed on the surface of CMC-Fe3O4-RB. Compared with RB, CMC-Fe3O4-RB had a larger specific surface area, pore volume and pore size. Meanwhile, nanomagnetic CMC-Fe3O4-RB solved the problem of agglomeration in traditional magnetized biochar production, and improved the adsorption capacity of Pb2+, which was 29.90% higher than that of RB by ICP-OES. Further, the Pb2+ (10 mg/L) adsorption capacity of CMC-Fe3O4-RB reached the highest level in 2 h at the dosage of 0.01 g/L, and remained stable at 52.987 mg/g after five cycles of adsorption and desorption. This research aided in the creation of a strategy for GBBs zero waste multistage usage and a circular economic model for GBBs industry development, which can be promoted and applied to the fields of food industry and environment improvement.


Assuntos
Ginkgo biloba , Poluentes Químicos da Água , Adsorção , Carboximetilcelulose Sódica , Carvão Vegetal , Extratos Vegetais , Poluentes Químicos da Água/análise
2.
J Chromatogr Sci ; 55(3): 358-365, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-27789527

RESUMO

In this paper, a high-performance liquid chromatography with ultraviolet (HPLC-UV) detection method, using tetraazacalix[2]arene[2]triazine-modified silica gel (NCS) as solid-phase extraction (SPE) sorbent, was developed for extracting and purifying the two phytohormones (indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA)) in chili and wheat samples from different organs of chili and wheat. The limits of detection were about 0.02 and 0.04 µg/mL, and the limits of quantification were 0.04 and 0.20 µg/mL for IAA and IBA, respectively. The intraday and interday RSDs (n = 6) of peak areas and retention times were in the range of 0.76-1.20%. In addition, overall recoveries through the extraction and NCS-SPE purification ranged from 78.4% to 86.8% for IAA and IBA were obtained. Compared with the commercial SPE sorbents, NCS featured excellent selectivity to retain IAA and IBA in the sample matrices. In addition, the results more clearly indicated that high IAA and IBA content existed in roots and leaves of wheat and chili; in other organs of the plants, the concentration of the two phytohormones is lower. The results from theoretical computation were consistent with the retention behaviors of IAA and IBA on NCS. The proposed NCS-SPE-HPLC method is highly effective for trace analysis of the two phytohormones in plant samples.


Assuntos
Calixarenos/química , Capsicum/química , Cromatografia Líquida de Alta Pressão/métodos , Reguladores de Crescimento de Plantas/análise , Extração em Fase Sólida/métodos , Triticum/química , Limite de Detecção , Modelos Lineares , Reguladores de Crescimento de Plantas/química , Reguladores de Crescimento de Plantas/isolamento & purificação , Reprodutibilidade dos Testes
3.
Talanta ; 146: 423-9, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26695285

RESUMO

A sensitive non-derivatization method was developed for the analysis of apramycin and impurites using hydrophilic interaction liquid chromatography (HILIC) and charged aerosol detection (CAD). Sample was pretreated with an effective SPE method (recovery >90%) to remove interference with apramycin impurities from sulfate, then analyzed with direct injection. Different chromatography modes of separation and choices of HILIC column were investigated in search of a direct analysis method. The HILIC-CAD method was optimized using a cysteine-bonded zwitterionic HILIC column and compared to the strong cation exchange-ultraviolet (SCX-UV) method with post-column derivatization recommended by the Chinese Pharmacopoeia (veterinary) 2010. The improved chromatographic resolution and peak shape with the HILIC-charged aerosol detection method allows for increase of sample load to 48.9 µg from only 2.8 µg with the SCX-UV approach. More than 16 impurities were detected with this method with improved resolution, and four were identified with MS, while only 7 impurities were detected with the SCX-UV method. Moreover, the current method has a good precision and reproducibility. The intra-day and inter-day of peak area variability was less than or equal to 4.760% RSD and 9.950%, respectively. The average limit of detection and quantization was 80 ng and 200 ng injected on the column, respectively. The overall results demonstrated that the presented method can be used as an alternative to SCX-UV method in the analysis of apramycin and impurities.


Assuntos
Cromatografia Líquida/métodos , Interações Hidrofóbicas e Hidrofílicas , Nebramicina/análogos & derivados , Aerossóis , Métodos Analíticos de Preparação de Amostras , Limite de Detecção , Nebramicina/análise , Nebramicina/química
4.
Se Pu ; 33(9): 938-42, 2015 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-26753280

RESUMO

Antiviral drugs are widely used for human and animals. However, the analysis of the mixture of antiviral drugs is a challenge for high performance liquid chromatography, since some of the antiviral drugs have weak UV absorbance and poor retention in reversed phase liq- uid chromatography. A method of hydrophilic interaction liquid chromatography-charged aerosol detection (HILIC-CAD) was optimized for the qualitative and quantitative analysis of five antiviral drugs. In this study, Click TE-Cys was used as the stationary phase and CAD was used as the detector. Various chromatographic conditions including the kind of detector, chromatographic mode, column and mobile phase composition were investigated. Compared to UV-Vis, more antiviral drugs could be detected by CAD, since it is a universal detector. HILIC mode is an alternative to reversed phase liquid chromatography mode. HILIC provides higher sensitivity and unique selectivity to target compounds. After the optimized parameters were obtained, the developed method was used for the quantitative analysis of the five antiviral drugs. As a result, the current method has good repeatability, a wide linear range (0.07-2.28 mg/mL) and good sensitivity (LOQ ≤ 0.04 mg/mL). The RSDs of intra-day and inter-day peak areas were less than 3. 06% and 5. 38% respectively. The above results demonstrated that the current method is sensitive, robust and effective for the separation and determination of these five antiviral drugs.


Assuntos
Antivirais/química , Cromatografia Líquida , Aerossóis , Cromatografia Líquida de Alta Pressão , Cromatografia de Fase Reversa , Química Click , Interações Hidrofóbicas e Hidrofílicas
5.
Artigo em Inglês | MEDLINE | ID: mdl-24269909

RESUMO

This paper described the preparation and application of a new dimethylethanolamine aminated polychloromethyl styrene nano-latex (DMEAPL) coated capillary column (ccc-DMEAPL) in the determination of four tetracycline antibiotics (TCA) including tetracycline (TC), oxytetracycline (OTC), doxycycline (DC) and chlorotetracycline (CTC) in pig plasma. The ccc-DMEAPL column was characterized with steady EOF values of ca. 1.5-5.2×10(-5)cm(2)/Vs at pH 1.8-6.3. The optimized conditions for field-amplified sample stacking open-tubular capillary electrochromatography (FASS-OT-CEC) were as following: background electrolyte, 10mmol/L Na2HPO4+15mmol/L citric acid (pH 3.2); ccc-DMEAPL, 50µm i.d.×50cm (effective length 41.5cm), separation voltage, 18kV; column temperature, 25°C; UV detection wavelength, 270nm; water-plug injection: 30mbar×10s; sample electrokinetic injection, 10kV×20s. The four TCA were extracted with the solution of 10mmol/L Na2HPO4+15mmol/L citric acid+4g/L EDTA-2Na (pH 3.2). The FASS-OT-CEC method was validated in terms of linearity, sensitivity, selectivity, precision and accuracy. The LODs ranged from 3 to 7ng/mL, the recoveries for the four TCA were all more than 80%. The developed method was successfully applied for the determination of TCs in the actual pig plasma samples.


Assuntos
Antibacterianos/sangue , Eletrocromatografia Capilar/instrumentação , Eletrocromatografia Capilar/métodos , Deanol/química , Nanopartículas/química , Tetraciclinas/sangue , Animais , Antibacterianos/química , Látex/química , Limite de Detecção , Modelos Lineares , Poliestirenos/química , Reprodutibilidade dos Testes , Suínos , Tetraciclinas/química
6.
J AOAC Int ; 88(6): 1644-8, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16526445

RESUMO

A high-performance liquid chromatography (LC) method was developed for the determination of halofuginone (HFG) in sturgeon muscle. The extracted samples were cleaned up by an immunoaffinity chromatography column that was prepared by covalently coupling polyclonal antibodies against HFG to cyanogen bromide (CNBr) activated Sepharose 4B. The eluate was evaporated to dryness, and residues were determined by LC with absorbance detection at 243 nm. Recoveries of HFG from samples fortified at 20-200 microg/kg levels ranged 74.6-81.1%, with coefficients of variation of 0.7-8.6%. The detection limit was estimated to be 10 microg/kg in a 2 g sample.


Assuntos
Técnicas de Química Analítica/métodos , Cromatografia de Afinidade/métodos , Cromatografia Líquida/métodos , Músculos/metabolismo , Quinazolinas/análise , Animais , Bass , Calibragem , Brometo de Cianogênio/química , Relação Dose-Resposta a Droga , Concentração de Íons de Hidrogênio , Modelos Químicos , Piperidinas , Quinazolinonas , Sefarose/análise , Solubilidade , Temperatura , Fatores de Tempo , Distribuição Tecidual
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