University of Basel, Department of Chemistry, Spitalstrasse 51, 4056 Basel, Switzerland.
Agilent Technologies, Hewlett-Packard Str. 8, 76337 Waldbronn, Germany.
Anal Chim Acta. 2017 Sep 15;986:95-100. doi: 10.1016/j.aca.2017.07.007. Epub 2017 Jul 12.
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%.
描述了一种基于八个不同发光二极管的光度计检测器，涵盖了从 255nm 到 350nm 的紫外线范围。这些二极管通过熔融石英光纤与 1cm 光程的常规比色皿或低体积流量通过池耦合，用于高效液相色谱中的检测。光电二极管用于测量透射强度以及参考信号，并且将光电流用对数比放大器处理，以获得与吸光度值成比例的电压。通过电子切换所需的发光二极管来选择当前测量所需的波长。该检测器的噪声水平低至 80μAU。在分批测量以及高效液相色谱检测中，都能够实现 2-3 个数量级的动态范围。在后一种应用中，峰面积的重现性优于 1%。
