SPECTROPHOTOMETRIC DETECTOR FOR CAPILLARY ELECTROPHORESIS AND FOR CHROMATOGRAPHIC CAPILLARY LIQUID Russian patent published in 2002 - IPC

FIELD: analytical instrumentation. SUBSTANCE: invention can find use in devices of capillary electrophoresis and in chromatographs conducting high-sensitivity detection of components of samples moving in capillary. Given spectrophotometirc detector has light source 1, input slit 2 and diffraction grating 3 placed in sequence in path of common light beam, beam splitter 5 sending split light beam into measurement channel carrying collector 6, measurement cell 7, second collector 8 and first photodetector 9 and into reference channel incorporating collector 10 and second photodetector 11. Illumination lens 18 is positioned between light source and input slit. Beam splitter comes in the form of plate placed in path of light after diffraction grating 3. Measurement and reference channels are provided with output slits 19 and 20 located after beam splitter 5 and photodetectors 9 and 11 of both channels are manufactured in the form of microcircuits in which photodiodes 12 and 13 are connected to inputs of nonlinear converters 21 and 22 of photocurrents to other physical quantities, for instance time intervals. Outputs of photodetectors of both channels are connected to microprocessor 16 which output is linked to registering unit 17. Plate of beam splitter is fabricated in the form of mirror with aperture in zone of passage of light beam in measurement channel. Nonlinear converter comes in the form of operational amplifier with capacitor in feedback circuit, comparators connected to output of amplifier and keys of initial setting connected to comparators and capacitor. Collectors in measurement channel are manufactured in the form of concave mirrors and light source is produced in the form of arc deuterium lamp and filament lamp which emitting region has vertical size larger than horizontal size. EFFECT: increased sensitivity and expanded dynamic range of detector. 4 cl, 2 dwg