da Silveira Petruci João Flavio, Liebetanz Michael G, Cardoso Arnaldo Alves, Hauser Peter C
Department of Chemistry, University of Basel, Spitalstrasse 51, 4056 Basel, Switzerland; São Paulo State University (UNESP), Department of Analytical Chemistry, CEP 14800-970, Araraquara, SP, Brazil.
Department of Chemistry, University of Basel, Spitalstrasse 51, 4056 Basel, Switzerland.
J Chromatogr A. 2017 Aug 25;1512:143-146. doi: 10.1016/j.chroma.2017.07.029. Epub 2017 Jul 11.
In this communication, we describe a flow-through optical absorption detector for HPLC using for the first time a deep-UV light-emitting diode with an emission band at 235nm as light source. The detector is also comprised of a UV-sensitive photodiode positioned to enable measurement of radiation through a flow-through cuvette with round aperture of 1mm diameter and optical path length of 10mm, and a second one positioned as reference photodiode; a beam splitter and a power supply. The absorbance was measured and related to the analyte concentration by emulating the Lambert-Beer law with a log-ratio amplifier circuitry. This detector showed noise levels of 0.30mAU, which is comparable with our previous LED-based detectors employing LEDs at 280 and 255nm. The detector was coupled to a HPLC system and successfully evaluated for the determination of the anti-diabetic drugs pioglitazone and glimepiride in an isocratic separation and the benzodiazepines flurazepam, oxazepam and clobazam in a gradient elution. Good linearities (r>0.99), a precision better than 0.85% and limits of detection at sub-ppm levels were achieved.
在本通讯中，我们描述了一种用于高效液相色谱（HPLC）的流通式光吸收检测器，该检测器首次使用发射带为235nm的深紫外发光二极管作为光源。该检测器还包括一个紫外敏感光电二极管，其位置设置为能够测量通过直径为1mm的圆形孔径和10mm光程长度的流通比色皿的辐射，另一个作为参考光电二极管；一个分束器和一个电源。通过使用对数比放大器电路模拟朗伯-比尔定律来测量吸光度并将其与分析物浓度相关联。该检测器的噪声水平为0.30mAU，与我们之前使用280nm和255nm发光二极管的基于LED的检测器相当。该检测器与HPLC系统相连，并成功用于等度分离中抗糖尿病药物吡格列酮和格列美脲以及梯度洗脱中苯二氮䓬类药物氟西泮、奥沙西泮和氯巴占的测定。实现了良好的线性（r>0.99）、优于0.85%的精密度以及亚ppm水平的检测限。
