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1.
Food Chem ; 304: 125383, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31479997

RESUMO

An aqueous two-phase system was used in conjunction with ultrasonic cell disruption to extract and separate solanine (mainly solasonine and solamargine) and Solanum nigrum polysaccharide from Solanum nigrum unripe fruit. The optimized conditions of the present study were determined by a single-factor experiment and a multifactor experiment. The concentration of ethanol was set at 60% and the duration of the ultrasonic cell disruption extraction was 50 min. In the ethanol-K2CO3 aqueous two-phase separation system, the concentration of ethanol was 36%, the concentration of K2CO3 was 0.21 mg·mL-1, and the temperature was 15 °C. The solasonine and solamargine were determined by high-performance liquid chromatography, and the Solanum nigrum polysaccharide was determined by an ultraviolet-visible spectrophotometer in accordance with the phenol-sulfuric acid method. xUnder optimized conditions, the average extraction efficiencies of solasonine, solamargine and Solanum nigrum polysaccharide were 95.86%, 95.95% and 96.95%, respectively, and the average separation efficiencies of solasonine, solamargine and Solanum nigrum polysaccharide were 2.07 mg·g-1, 2.05 mg·g-1 and 8.15 mg·g-1, respectively.

2.
Talanta ; 168: 16-22, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28391836

RESUMO

In this work, a novel and facile ratiometric fluorescence probe was prepared for the visual detection of dopamine (DA). In this detection system, red-emission CdTe@SiO2 (r-QDs@SiO2) was used as steady core of the probe and inverse microemulsion method was applied to synthesize uniform r-QDs@SiO2, this step could protect CdTe from contacting with human skin directly. Polydopamine (PDA) acted as response signal to detect DA, a very handy method which just combined polyethyleneimine (PEI) with DA together to synthesize PDA, this way for synthesis of PDA was much time-saving and non-toxic than any other methods. Differently from traditional analysis processes, the products of this experiment were also the analysis substances in final. Under optimum measurement conditions, the dual-emission ratiometric fluorescence probe was used for detections of DA in a concentration ranged from 10µM to 80µM with a detection limit of 0.12µM, with addition of DA the color of the probe changed from red to green watched by naked eyes. In addition, the developed probe was also used for detections of DA in human serum samples successfully. This study provides a simple, time-saving and non-toxic approach for detections of DA without the requirement of complex equipment.


Assuntos
Técnicas Biossensoriais/métodos , Fluorescência , Corantes Fluorescentes/química , Indóis/sangue , Espectrometria de Fluorescência/métodos , Humanos , Limite de Detecção , Polímeros
3.
Ecotoxicol Environ Saf ; 133: 105-13, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27434421

RESUMO

Polyoxyethylene lauryl ether (POELE10)-Na2C4H4O6 aqueous two-phase extraction system (ATPES) is a novel and green pretreatment technique to trace samples. ATPES coupled with high-performance liquid chromatography (HPLC) is used to analyze synchronously sulfadiazine (SDZ) and sulfamethazine (SMT) in animal by-products (i.e., egg and milk) and environmental water sample. It was found that the extraction efficiency (E%) and the enrichment factor (F) of SDZ and SMT were influenced by the types of salts, the concentration of salt, the concentration of POELE10 and the temperature. The orthogonal experimental design (OED) was adopted in the multi-factor experiment to determine the optimized conditions. The final optimal condition was as following: the concentration of POELE10 is 0.027gmL(-1), the concentration of Na2C4H4O6 is 0.180gmL(-1) and the temperature is 35°C. This POELE10-Na2C4H4O6 ATPS was applied to separate and enrich SDZ and SMT in real samples (i.e., water, egg and milk) under the optimal conditions, and it was found that the recovery of SDZ and SMT was 96.20-99.52% with RSD of 0.35-3.41%. The limit of detection (LOD) of this method for the SDZ and SMT in spiked samples was 2.52-3.64pgmL(-1), and the limit of quantitation (LOQ) of this method for the SDZ and SMT in spiked samples was 8.41-12.15pgmL(-1).


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Polietilenoglicóis , Sulfadiazina/isolamento & purificação , Sulfametazina/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Análise de Variância , Resíduos de Drogas/isolamento & purificação , Limite de Detecção , Polidocanol , Reprodutibilidade dos Testes , Cloreto de Sódio , Temperatura Ambiente , Água/química
4.
Food Chem ; 210: 1-8, 2016 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-27211613

RESUMO

Smart polymer aqueous two phase flotation system (SPATPF) is a new separation and enrichment technology that integrated the advantages of the three technologies, i.e., aqueous two phase system, smart polymer and flotation sublation. Ethylene oxide and propylene oxide copolymer (EOPO)-(NH4)2SO4 SPATPF is a pretreatment technique, and it is coupled with high-performance liquid chromatography to analyze the trace ciprofloxacin and lomefloxacin in real food samples. The optimized conditions of experiment were determined in the multi-factor experiment by using response surface methodology. The flotation efficiency of lomefloxacin and ciprofloxacin was 94.50% and 98.23% under the optimized conditions. The recycling experimentsshowed that the smart polymer EOPO could use repeatedly, which will reduce the cost in the future application.


Assuntos
Ciprofloxacino/análise , Fluoroquinolonas/análise , Alimentos , Cromatografia Líquida de Alta Pressão/métodos , Análise de Alimentos , Polímeros/química
5.
Food Chem ; 192: 163-70, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26304334

RESUMO

Polyoxyethylene lauryl ether (POELE10)-NaH2PO4 aqueous two-phase extraction system (ATPES) is coupled with HPLC to analyze chloramphenicol (CAP) in aquatic product. Response surface methodology (RSM) was adopted in the multi-factor experiment to determine the optimized conditions. The extraction efficiency of CAP (E%) is up to 99.42% under the optimal conditions, namely, the concentration of NaH2PO4, the concentration of POELE10, pH and temperature were 0.186 g · mL(-1), 0.033 g · mL(-1), 3.8 and 25 °C respectively. The optimal value of enrichment factor of CAP (F) was 22.56 when the concentration of NaH2PO4 was 0.192 g · mL(-1), the concentration of POELE10 was 0.024 g/ml, pH was 4.2 and temperature was 30 °C. The limit of detection (LOD) and limit of quantification (LOQ) of this method are 0.8 µg · kg(-1) and 1 µg · kg(-1), which meet the needs of determining trace or ultratrace CAP in food. The E% and F of this technique are much better than other extraction methods.


Assuntos
Cloranfenicol/análise , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Penaeidae/química , Polietilenoglicóis/química , Poluentes Químicos da Água/análise , Animais , Cromatografia Líquida de Alta Pressão/métodos , Análise de Alimentos/instrumentação , Limite de Detecção , Polidocanol , Rios/química , Água do Mar/química
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