A review of indirect photometric and fluorometric detection in high-performance liquid chromatography (HPLC) is presented. A functional definition of indirect detection, somewhat broader and simpler than what was often used to characterize these techniques, was employed for this review. Emphasis was placed on distinguishing different approaches to indirect photometric and fluorometric detection...

Neutronirradiation effects on optical absorption of solid-state nuclear track detector, CR-39 was studied for the various fluences ranging from 2.38x106 to 2.7x108 n/cm by ultraviolet-visible (UVVis) spectroscopy. The optical absorption spectra in the wavelength range of 200-700nm were recorded for the pristine and the neutron irradiated samples in the above fluence range. The UV-visible spectr...

A HPLC method with UV detection for quantification of 2,6-diaminopimelic acid (DAPA) in rumen bacteria, duodenal and ileal digesta and faeces is described. Biological samples were hydrolyzed with 6 M HC1 for 20 h at 104±2°C. DAPA was separated after pre-column derivatization with o-phthaldialdehyde (OPA) in the presence of ethanethiol (ESH). DAPA derivative was analyzed using a reversed-phase C...

The universe would have been completely dark between the epoch of recombination and the development of the first non-linear structure. But at redshifts beyond 5 – perhaps even beyond 20 – stars formed within 'subgalaxies' and created the first heavy elements; these same systems (together perhaps with 'miniquasars') generated the UV radiation that ionized the IGM, and maybe also the first signif...

Mixture experimental design was used to enhance the separation selectivity of metal ions in nonaqueous capillary electrophoresis. The separation of cations (Ag, Fe, Cr, Mn, Cd, Co, Pb, Ni, Zn and Cu) was achieved using imidazole as UV co-ion for indirect detection. Acetic acid was chosen as an electrolyte because its cathodic electroosmotic flow permits faster separation. The composition of org...

A general analytical method based on capillary electrophoresis with indirect UV detection has been developed to separate and quarntify N-methylmorpholine-N-Oxide (NMMO) and its main degradation products iV-methylmorpboline (NMM) and morpholine (M). The electrolyte is based on the two major components 4-methylbenzylamine and 2hydlroxy-2-methylpropanoic acid (hydroxyisobutyric acid, HIBA), tbe la...

A method for the determination of fatty acids in vegetable oils by capillary electrophoresis with indirect UV-vis detection has been developed. The separation of fatty acids was optimized in terms of Brij surfactant nature and concentration and organic modifier (2-propanol) percentage. The optimal background electrolyte consisted of 10 mM p-hydroxybenzoate, 5 mM Tris at pH 8.8, 80 mM Brij 98, 4...

Ultraviolet (UV) studies in astronomy, cosmology, planetary studies, biological and medical applications often require precision detection of faint objects and in many cases require photon-counting detection. We present an overview of two approaches for achieving photon counting in the UV. The first approach involves UV enhancement of photon-counting silicon detectors, including electron multip...

Drosophila vision is mediated by inputs from three types of photoreceptor neurons; R1-R6 mediate achromatic motion detection, while R7 and R8 constitute two chromatic channels. Neural circuits for processing chromatic information are not known. Here, we identified the first-order interneurons downstream of the chromatic channels. Serial EM revealed that small-field projection neurons Tm5 and Tm...