A 3D-Printed, pump-free, microfluidic hydride generation-capillary point discharge atomic emission spectrometer for...

Conventional atomic spectrometric techniques provide high sensitivity and accuracy for element detection, yet remain constrained by large instrument size, high gas consumption, and operational complexity. Recent advances in 3D printing technology have enabled new approaches to spectral instrument miniaturization which presents new opportunities for portable, on-site analysis.

A fully integrated, 3D-printed hydride generation-capillary point discharge atomic emission spectrometer (HG-CPD-AES) was constructed for on-site arsenic speciation analysis of environmental water samples. A monolithic unit containing the microfluidic reaction chamber, a gas-liquid separator and a coaxial capillary-tungsten electrode excitation source were fabricated by stereolithography and allows direct microsyringe injection of a tiny total sample volume of 150 μL. Hydride vapor confined by the quartz capillary enhances injection efficiency and signal stability. With a total gas flow rate of just 5 mL min^-1 (less than 1/20 of a conventional system), the system achieved a limit of detection of 4 μg L^-1 with a linear range of 10-3000 μg L^-1. The method was validated through analysis of tap water, pond water, and hot spring water samples with 100-110% recoveries and without significant difference in comparison with those by ICP-MS.

The cost-effective and open-source design enables rapid replication in various environments, creating a scalable and robust distributed detector platform. This approach facilitates on-site arsenic monitoring in resource-limited settings where conventional analytical infrastructure is unavailable or impractical to deploy.