A ۳D Printed Microfluidic Device in Combination with Smart‐Phone-Based Colorimetric Detection for Field Analysis of Heavy Metals

In the present work, a portable microfluidic chip was ۳D printed and coupled with a smartphone-based colorimetric detection system and applied for field analysis of heavy metals (mercury and lead) in environmental water samples. The procedure was based on complex formation between heavy metal and dithizone ligand, on both sides of a porous membrane. The color intensity was graded using a smartphone, exploited as the detection and data processing system. Different experimental parameters affecting the analytical signal including acid concentration in sample solution, concentration of ligand, and contact time were studied and optimized using a multivariate optimization design. Under the optimum conditions, the method showed a linear dynamic range between ۰.۵ and ۱۰۰ μg mL−۱ with a determination coefficient of ۰.۹۹۵۳. The limits of detection and quantification were obtained ۰.۱ and ۰.۳ μg mL−۱, respectively. The method provided a precise۲determination with relative standard deviations in the range of ۴.۱–۵.۳%. The seutp was successfully applied for the determination of heavy metals in wastewater, and tap water samples with spiking recoveries in the ranges of ۹۳–۹۸%, and ۸۹–۹۷%, respectively.