The Study Of Liquid Chromatography Detector Based On Solid-state Imaging Device

The liquid chromatography detector is one of the chromatography systems, and it takes avery important role in the liquid chromatography. The multi-wavelength detecting and highperformance is main developing trend of the liquid chromatography detector.A few design projects based on the solid imaging device are introduced in the paper.(1) Firstly a multi-wavelength UV-Visible absorbance detector based on SSPD isdesigned. The ray of light source shines into sample cell after the lens. The light which is notabsorbed by the sample is gathered by optical fibers. It falls onto the concave grating after theslot and images on the SSPD. The detector can detect the chromatography signals fromsixteen channels at the same time.(2) In order to detect the chromatography signals for more cchannels, a single beam diodearray detector based on optical fibers is designed.The system uses optical fibers and concavegrating as the spectrometer, and SSPD as the light sensor. The system can measure the darkcurrent of the SSPD and utilize it to conquer its influence, and adapt the inner referencetechnology to depress the noise and drift of detector which resulted by the intensityfluctuation of the light source.The detector can detect all the chromatography signals in therange of the wavelength which can be detected.(3) In order to depress the noise and drift of detector which resulted by the intensityfluctuation of the light source, a dual beam diode array detector based on optical fibers isdesigned. The ray of light source is divided into signal beam and reference beam by the fibers.The dual beam respectively shines into the sample pool and reference pool after it passesthrough the chopper. Both project signal ray and reference ray are collected by the fibers andimaged on the photodiode array by concave grating after slot. The signal spectrum, referencespectrum and dark current of SSPD can be measured on the same SSPD, so it can effectivelydepress the noise and drift of detector.(4) Because the ultraviolet fiber is costly and has a limited life, a dual beam diode arraydetector based on beam splitter is designed. The detector realizes the splitting and combiningof light by the beam splitter, uses the concave grating as the spectrometer and the photodiodearray as the light sensor. The signal spectrum, reference spectrum and dark current of SSPDcan be measured on the same SSPD under the cooperation of the chopper and accessorialcircuits. (5) Because compared with the photodiode array the back-thinned type CCD has manybenefits, such as low dark current, high quantum efficiency and low read-out noise levels etc,a dual gratings multi-wavelength UV-Vis detector based on CCD is designed. The detectoradopts the dual beam configuration. The signal beam and the reference beam shine onto eachslot of the Spectrometer and images on different portions of CCD by the concave grating. Thesignal spectrum, the reference spectrum and the dark current of CCD can be measured on thesame CCD.(6) A single gratings multi-wavelength UV-Vis detector based on CCD is designed. Thedetector adopts the dual beam configuration. The signal beam shines into the sample cell. Thesignal beam and the reference beam image on the CCD by the same concave grating after theypasses through the chopper and each slot. The signal spectrum and reference spectrum can beobtained by the useless light correction arithmetic.