Flow rate dependent extra-column variance from injection in capillary liquid chromatography.

Efficiency and resolution in capillary liquid chromatography (LC) can be significantly affected by extra-column band broadening, especially for isocratic separations. This is particularly a concern in evaluating column bed structure using non-retained test compounds. The band broadening due to an injector supplied with a commercially available capillary LC system was characterized from experimental measurements.

Fabrication of highly cross-linked reversed-phase monolithic columns via living radical polymerization.

New monolithic reversed-phase liquid chromatography (RPLC) stationary phases based on single multi-acrylate/methacrylate-containing monomers [i.e., 1,12-dodecanediol dimethacrylate (1,12-DoDDMA), trimethylolpropane trimethacrylate (TRIM) and pentaerythritol tetraacrylate (PETA)] were synthesized using organotellurium-mediated living radical polymerization (TERP), which was expected to produce more efficient monolithic columns than conventional free-radical polymerization.

High efficiency polyethylene glycol diacrylate monoliths for reversed-phase capillary liquid chromatography of small molecules.

Highly cross-linked monolithic networks (i.e., polyethylene glycol diacrylate, PEGDA) synthesized from monomers containing varying ethylene oxide chain lengths were fabricated inside fused silica capillary columns for use in liquid chromatography (LC) of small molecules.

Correlation of chromatographic performance with morphological features of organic polymer monoliths.

Monoliths are considered to be a low pressure alternative to particle packed columns for liquid chromatography (LC). However, the chromatographic performance of organic monoliths, in particular, has still not reached the level of particle packed columns. Since chromatographic performance can be attributed to morphological features of the monoliths, in-situ characterization of the monolith structure in three dimensions would provide valuable information that could be used to help improve performance.

Highly crosslinked polymeric monoliths with various C6 functional groups for reversed-phase capillary liquid chromatography of small molecules.

Three crosslinking monomers, i.e., 1,6-hexanediol dimethacrylate (HDDMA), cyclohexanediol dimethacrylate (CHDDMA) and 1,4-phenylene diacrylate (PHDA), were used to synthesize highly cross-linked monolithic capillary columns for reversed-phase liquid chromatography (RPLC) of small molecules.

Organic monoliths for high-performance reversed-phase liquid chromatography.

RPLC is the most common mode of LC. It is widely used for separations of both small and large molecules. Monolithic columns, which are currently under intensive study by many groups, have the potential of becoming attractive alternatives to particle-packed columns.

Neurobehavioral sequelae of child sexual abuse.

This study examined intellectual and memory functioning in a sample of sexually abused children compared to demographically and age-matched controls. The severity of abuse and other pertinent factors were also examined in relation to cognitive performance. Elevated levels of psychopathology were present in the abused children, as well as diminished performance on tasks influenced by attention/concentration.

Memory performance of children with dyslexia: a comparative analysis of theoretical perspectives.

This study examined the memory performance of children with reading disabilities (RD) using methodology representative of three theoretical perspectives on RD subtypes: the phonological deficit, dual route, and phonological-core variable-difference models. Analyses compared the serial memory, verbal learning, and abstract visual-spatial memory performance of 45 children with RD to that of chronological-age (CA)- and reading-level (RL)-matched controls, using subtype identification methods from each of the theoretical models to classify children with RD. Phonological deficit and dual route comparisons indicated that children with RD, regardless of subtype, performed more poorly than CA- and better than RL-matched participants on all memory tasks.