The study of the interactions between heavy metals with sulfonylurea herbicides using ACE.
(11/41)
The affinity capillary electrophoresis method was used in the study of interactions between heavy metals (Pb, Mn, La, Cd, and Ni) and the sulfonylurea herbicides (thifensulfuron, nicosulfuron and sulfometuron). A buffer of 50 mM acetate (pH 5.85) was employed in the study. The results proved that there are two binding sites in the herbicides when chelating with the heavy metals. Binding constants of the high chelating ability sites between them were in the range of 10(3) to 10(5), and the other were in the range of 10 to 10(3). Thifensulfuron is the most powerful chelator among the three herbicides. Ni is of the weaker chelators, within the herbicides than Pb, Mn, La, and Cd. The binding abilities were proven to be increased with the pH value among the investigated range. (+info)
Determination of zeta-potential and tortuosity in rat organotypic hippocampal cultures from electroosmotic velocity measurements under feedback control.
(12/41)
Ecstasy analysis by monolithic materials-capillary electrochromatography.
(14/41)
Monolithic columns were successfully prepared and used with capillary electrochromatography for the analysis of 3,4-methylenedioxymethamphetamine (MDMA) in ecstasy tablets and its metabolites in urine samples. Cationic and neutral monolith columns provided better efficiencies than anionic monoliths. The neutral butyl methacrylate (BMA) monolith column provided symmetrical peaks with the highest efficiency, high resolution and short analysis times. The developed method using BMA monolithic column provided the detection limits for MDMA and its metabolites at 1 microg mL(-1) with excellent intra-day and inter-day precision and linearity from 7.5 to 100 microg mL(-1) (R(2) > or = 0.99). MDMA was found as the main component in ecstasy tablets while 4-hydroxy-3-methoxymethamphetamine as the major metabolite in urine samples. High recoveries (97% for MDMA from tablets and 84-102% for its metabolites from urine samples) were obtained using simple ultrasonic extraction for ecstasy tablets and liquid-liquid extraction for urine samples. (+info)
Creation of functional micro/nano systems through top-down and bottom-up approaches.
(15/41)
Mimicking nature's approach in creating devices with similar functional complexity is one of the ultimate goals of scientists and engineers. The remarkable elegance of these naturally evolved structures originates from bottom-up self-assembly processes. The seamless integration of top-down fabrication and bottom-up synthesis is the challenge for achieving intricate artificial systems. In this paper, technologies necessary for guided bottom-up assembly such as molecular manipulation, molecular binding, and the self assembling of molecules will be reviewed. In addition, the current progress of synthesizing mechanical devices through top-down and bottom-up approaches will be discussed. (+info)
Ion exchange resin bead decoupled high-pressure electroosmotic pump.
(16/41)