کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5130611 1490846 2017 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Molecular absorption measurements with an optical fibre coupled array of ultra-violet light-emitting diodes
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Molecular absorption measurements with an optical fibre coupled array of ultra-violet light-emitting diodes
چکیده انگلیسی


- The detector features 8 LEDs covering the wavelength range from 255 to 350 nm.
- The use of optical fibres allows the coupling of all sources to a single photometric cell.
- Switching of LEDs is entirely electronic.

A photometric detector based on eight different light-emitting diodes covering the ultraviolet range from 255 nm to 350 nm is described. These are coupled with fused silica optical fibres to a conventional cuvette with 1 cm optical path length or to a low volume flow through cell for detection in high-performance liquid chromatography. Photodiodes are employed for the measurement of the transmitted intensity as well as of a reference signal and the photocurrents are processed with a log-ratio amplifier to obtain a voltage proportional to absorbance values. The wavelength desired for the measurement at hand is selected by electronically switching on the requisite light-emitting diode. The detector was found to have a low noise level of 80 μAU. In batch-wise measurements as well as in detection for high-performance liquid chromatography dynamic ranges of 2-3 orders of magnitude were possible. Reproducibilities in peak areas for the latter application were better than 1%.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Analytica Chimica Acta - Volume 986, 15 September 2017, Pages 95-100
نویسندگان
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