Several detection techniques, such as UV-VIS spectroscopy, fluorescence spectroscopy and mass spectrometry have been employed in analytical liquid chromatography (LC) for many years. While UV and fluorescence detectors sometimes require labelling of compounds to enable their detection, MS instrumentation is universal but quite expensive. In recent years, the development of millimeter wave- and 3D-printing technology  has enabled the monitoring of interactions between electromagnetic waves and biological substances in micro-fluidic channels. Due to the dielectric difference between bio-molecules and mobile phases used in LC, it is possible to achieve universal detection without labelling work. In this study, a millimeter-wave sensor with operation frequency at 60 Giga-Hertz is developed and evaluated for its applicability as label-free and universal detector for a capillary liquid chromatographic system. 3D printing technology is used to fabricate the sensor structure to guarantee not only sensitivity but also to enable the microfluidic compatibility with the system as well. As a proof-of-concept demonstration, 2 UV absorbing substances (trans-stilbene oxide and praziquantel) and 1 non-UV absorbing compound (sorbitol) are injected into an open-tube setup of the LC system. The results of the millimeter wave detecor are compared to that of an UV detector which is integrated in the LC instrument. The outcome shows potential of the millimeter wave sensor as an alternative label-free detector.
|Title of host publication||The 39th Symposium Chromatographic Methods of Investigating the Organic Compounds|
|Publication status||Published - 3 Jun 2016|
|Event||The 39th Symposium Chromatographic Methods of Investigating the Organic Compounds - Szczyrk, Poland|
Duration: 31 May 2016 → 3 Jun 2016
|Conference||The 39th Symposium Chromatographic Methods of Investigating the Organic Compounds|
|Period||31/05/16 → 3/06/16|