Search results for "solution"

Electrokinetic capillary chromatography in a polar continuous‐phase water‐in‐oil microemulsion constituted by water, sodium dodecyl sulfate, and n ‐p…

2005

A water-in-oil (w/o) microemulsion (ME) constituted by 15% Tris buffer, pH 8.4, in water and 85% sodium dodecyl sulfate (SDS)/n-pentanol 1:4 mixture, capable of dissolving up to 30% vegetable oils and lard, was used as background electrolyte in reverse microemulsion electrokinetic capillary chromatography (RMEEKC). Owing to the free SDS ions in the continuous phase and some degree of percolation, the ME showed a high conductivity (0.65 mS. cm(-1) at 25 degrees C) and sustained a very stable capillary current. Previous rinsing of the capillary with a quaternary ammonium salt for electroosmotic flow (EOF) reduction, a series of nonionic and anionic solutes dissolved either in the ME or in fat…

Development and validation of a micellar liquid chromatographic method to determine three antitumorals in plasma

2017

Aim: A micellar liquid chromatographic method to determine several anticancer drugs (pazopanib, dabrafenib and regorafenib) in plasma was developed and validated by the guidelines of the EMA. Experimental: Plasma samples were directly injected, after a 1/5-dilution in a micellar solution. The drugs were resolved in <18 min using a C18 column. The mobile phase was an aqueous solution of 0.12 M SDS – 2% 1-pentanol, buffered at pH 7. The detection was performed by absorbance at 260 nm. Results: The values of the main validation parameters were: LOD (0.1–1 mg/l), calibration range (0.2–2 to 80 mg/l), accuracy (-12.5 to +11.7%) and precision (<11.9%). Conclusion: The procedure was conduct…

Comparison of several methods used for the determination of cephalosporins. Analysis of cephalexin in pharmaceutical samples

2002

The precision of UV absorbance of intact and acid degraded cephalosporins, ninhydrin, high performance liquid chromatography and iodometric methods used for analysis of cefoxitin, cefotaxime, cephazolin and cephalexin were compared. To obtain the calibration graphs the analytical signal used were: absorbance, first derivative absorbance, second derivative absorbance and H-point Standard Additions Method by using absorbance values at two selected wavelengths as analytical signal. These methods and calibration graphs were also used for the determination of cephalexin in pharmaceutical samples.

Furosemide assay in pharmaceuticals by Micellar liquid chromatography: study of the stability of the drug.

2000

A simplified high-performance liquid chromatographic procedure is described for the determination of furosemide (4-chloro-N-furfuryl-5-sulphamoylanthranillic acid), which makes use of UV detection, a C18, reversed-phase column, and micellar mobile phases of sodium dodecyl sulphate (SDS) and 1-propanol at pH 3 buffered with phosphate system. The most adequate experimental conditions to handle furosemide solutions in the analytical laboratory are studied. The mixture of furosemide and its degradation products which are formed upon light exposition was resolved with a mobile phase of 0.04 M SDS-2% propanol. Separation of furosemide from its common impurities and the hydrolytic product, 4-chlor…

Future Trends in Confocal Laser Endomicroscopy: Improved Imaging Quality and Immunoendoscopy

2007

Confocal laser endomicroscopy (CLE) is a powerful new technique that permits subsurface imaging at high resolution during ongoing endoscopy in the upper and lower GI tract [1]. Here, we will discuss future trends in CLE and their potential application in clinical practice. In particular, we will focus on molecular imaging using labelled antibodies for immunoendoscopy.

FP247RENAL ALTERATIONS AFTER A MARATHON AND THE IMPACT OF POSTRACE RECOVERY METHOD ON THEIR RESOLUTION: A CLINICAL TRIAL

2018

Singular solutions to p-Laplacian type equations

1999

We construct singular solutions to equations $div\mathcal{A}(x,\nabla u) = 0,$ similar to the p-Laplacian, that tend to ∞ on a given closed set of p-capacity zero. Moreover, we show that every Gδ-set of vanishing p-capacity is the infinity set of some A-superharmonic function.

Robustified smoothing for enhancement of thermal image sequences affected by clouds

2015

Obtaining radiometric surface temperature information with both high acquisition rate and high spatial resolution is still not possible through a single sensor. However, in several earth observation applications, the fusion of data acquired by different sensors is a viable solution for so called image sharpening. A related issue is the presence of clouds, which may impair the performance of the data fusion algorithms. In this paper we propose a robustified setup for the sharpening of thermal images in a non real-time scenario, capable to deal with missing thermal data due to cloudy pixels, and robust with respect to cloud mask misclassifications. The effectiveness of the presented technique…

Phase behavior of aqueous solutions of bovine serum albumin in the presence of dextran, at rest, and under shear.

2006

The demixing conditions for aqueous solutions of bovine serum albumin (BSA, fraction V) and for joint solutions of BSA plus dextran (DEX, M(w) = 2000 kg/mol) were determined by turbidimetric measurements as a function of composition, temperature, and shear rate. Aqueous solutions of BSA phase separate upon heating. Within the region of BSA concentrations between 0.05 and 32 wt %, the demixing temperature, T1, falls from ca. 65 degrees C to an almost constant value of 45 degrees C. Adding DEX to the BSA solutions reduces the homogeneous region of the mixture drastically where the amount of DEX required to lower T1 to 25 degrees C decreases rapidly as the concentration of BSA is raised. Exper…

Small-Angle Neutron Scattering from Aqueous Solutions of C12E6 and C12E8: Critical Fluctuations and Micellar Growth

1986

Static SANS measurements have been performed on 0.028 M C12E8 in D2O over the temperature range 20–74.2 °C. Little micellar growth is observed; increases in the scattered intensities in the low angle region are due to critical concentration fluctuations of correlation length g. We have also reexamined our SANS data for C12E6 in D2O, in light of other worker’s claims that a sphere-to-cylinder transition in micellar shape is occurring in these solutions. We discuss in detail the inferences about C12E6 micellar size drawn from the results of several different experimental techniques.