Abstract by Thy Truong
Chemistry and Biochemistry
Optimizing LED-based UV Absorption Detectors for On-column Capillary Liquid Chromatography
Many traditional time-consuming and labor-intensive methods for collecting, transporting and preparing samples for analysis in a laboratory are being eliminated by the use of on-site portable instruments. This trend raises concerns of how accurate and reliable measurements in the field are. In liquid chromatography (LC), ultraviolet (UV) absorption detectors with standard light sources, such as mercury lamps, were never intended for use in the field or for point-of-care, especially in miniature LC systems. Hence, there is a need for greatly improving this detector for field use. An LED light source has advantages of long life, excellent stability, low cost, low power consumption and the convenience of small size. In this work, 260 and 280 nm LED-based UV-absorption detectors were specifically designed for on-column detection in nano-flow LC. By precisely positioning two ball lenses, a band-pass filter, and a fixed slit in an integrated fixture that focused the light from the LED directly in the center of the 0.150 mm LC capillary column, excellent signal intensity, low noise and stable signal were observed.