Open-Source Absorbance Detector with Multiple Deep UV-LEDs for On-Capillary Multiwavelength Detection at a Single Point

On-capillary ultraviolet photometric detection (UV-PD) in a multiwavelength mode provides comprehensive analytical information. However, achieving single-point multiwavelength UV-PD for capillary-scale instruments typically requires high-cost and complex devices. This study presents the development of a cost-effective, open-source absorbance detector for on-capillary multiwavelength detection. The detector employs three deep UV light-emitting diodes emitting at 235, 255, and 278 nm as light sources, each coupled with its own photodetector for independent detection channels. The components are housed using 3D-printed parts, with an Arduino board used for data acquisition. Three individual optical paths, formed by three slits (60 μm width ×1 mm length), surround the measured capillary and converge at the same detection point. The detector demonstrates simultaneous multiwavelength detection of medicines for both HPLC and CE. This development represents an advancement in portable, low-cost analytical instrumentation, with broad implications for various fields of application.