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Vortex-assisted dispersive liquid-liquid microextraction based on the solidification of sedimentary deep eutectic solvents was developed and applied to the extraction of triazine and phenylurea herbicides in milk samples. In this study, a series of novel hydrophobic deep eutectic solvents were prepared using tetrabutylammonium chloride as the hydrogen bond acceptor and perfluorooctanol as the hydrogen bond donor, and their structures, viscosities, densities and melting points were determined. The deep eutectic solvent was used as the extraction solvent and dispersed in the sample solution with the assistance of vortex. After extraction, through centrifugation and subsequent cooling in an ice bath, the deep eutectic solvent was solidified and deposited on the bottom of the centrifuge tube. Subsequently, the deep eutectic solvent combined with the target analytes was diluted and used for chromatographic analysis. Some parameters, including the extraction temperature, type and volume of the deep eutectic solvent, amount of NaCl, vortex time and pH of the sample solution, were optimized by the single-factor experiment, Plackett-Burman design and Box-Behnken design. The limits of detection and quantification were in the range of 0.41-0.59 µg L-1 and 1.37-1.95 µg L-1, respectively. The intra-day precision and inter-day precision were in the range of 0.28-2.14% and 2.02-7.99%, respectively. The present method was successfully applied to the determination of triazine and phenylurea herbicides in milk samples.
Assuntos
Herbicidas , Microextração em Fase Líquida , Animais , Solventes Eutéticos Profundos , Herbicidas/análise , Limite de Detecção , Microextração em Fase Líquida/métodos , Leite/química , Triazinas/análiseRESUMO
Objective To evaluate the application of fast-FLAIR T 2WI and enhanced fat-suppressed T 1WI in diagnosis of meningeal disorders.Methods Fast-FLAIR T 2WI and enhanced fat-suppressed T 1WI imaging for 38 patients with meningeal disorders were contrastingly studied.Results Meningeal disorders foci were found in all patients. 55 foci were displayed with fast-FLAIR T 2WI and 59 with enhanced fat-suppressed T 1WI.Conclusions The fast-FLAIR T 2WI and enhanced fat-suppressed T 1WI are all useful to improve the detection of meningeal disorders.
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Objective To explore the change of the activities of peroxisome ?-oxidation in T2DM patients with the lipid disorders.Methods We analyzed the changes of the activities of peroxisome ?-oxidation and fatty acyl-CoA oxidase and its mRNA expression in 112 cases of T2DM patients.Results We found that there was compensatory increase in activity of peroxisome ?-oxidation of T2DM patients.As compared with control group,the activity of fatty acyl-CoA oxidase of T2DM group was increased by 5%(P
RESUMO
AIM:To study the electrophysiological effects of resveratrol from grape and polygonum cuspidate on autorhythmicity organization in left ventricular outflow tract of guinea pig and its intracellular mechanism.METHODS:In choosing guinea pig weighing 250~300 g,the action potential,including its MDP(maximal diastolic potential),APA(amplitude of AP),Vmax(maximal rate of zero phase depolarization),VDD[velocity of diastolic(phase 4)depolarization],RPF(rate of pacemaker firing)and APD_ 50,APD_ 90(the duration of 50% and 90% repolarization of action potential),were observed and recorded by means of the intracellular microelectrode technique.RESULTS:(1)Resveratrol could reduce the electric activity of left ventricular outflow tract.Resveratrol(30、60、120 ?mol/L)not only significantly decreased APA and Vmax,but also decreased VDD and RPF respectivily(P
