Department of Chemistry, University of Basel, Basel, Switzerland; Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Hanoi, Vietnam.
J Sep Sci. 2013 Oct;36(19):3152-7. doi: 10.1002/jssc.201300598. Epub 2013 Aug 23.
A detector for miniaturized HPLC based on deep UV emitting diodes and UV photodiodes was constructed. The measurement is accomplished by the transverse passage of the radiation from the light-emitting diode (LED) through fused-silica tubing with an internal diameter of 250 μm. The optical cell allows flexible alignment of the LED, tubing, and photodiode for optimization of the light throughput and has an aperture to block stray light. A beam splitter was employed to direct part of the emitted light to a reference photodiode and the Lambert-Beer law was emulated with a log-ratio amplifier circuitry. The detector was tested with two LEDs with emission bands at 280 and 255 nm and showed noise levels as low as 0.25 and 0.22 mAU, respectively. The photometric device was employed successfully in separations using a column of 1 mm inner diameter in isocratic as well as gradient elution. Good linearities over three orders of magnitude in concentration were achieved, and the precision of the measurements was better than 1% in all cases. Detection down to the low micromolar range was possible.
构建了一种基于深紫外发光二极管和紫外光电二极管的微型化 HPLC 检测器。通过将发光二极管 (LED) 的辐射横向穿过内径为 250μm 的熔融硅石管来进行测量。该光学池允许灵活地对准 LED、管道和光电二极管，以优化光通量，并具有一个孔径来阻挡杂散光。采用分光器将部分发射光引导到参考光电二极管，并使用对数比放大器电路模拟朗伯-比尔定律。该检测器已用发射带分别为 280nm 和 255nm 的两个 LED 进行了测试，其噪声水平分别低至 0.25 和 0.22 mAU。该光度仪在使用内径为 1mm 的柱进行等度和梯度洗脱的分离中成功使用。在浓度的三个数量级上实现了良好的线性度，并且在所有情况下测量的精度均优于 1%。可以实现低至微摩尔级的检测。
