Microfluidic Analysis System Integrated with Liquid. liquid Extraction and Liquid-liquid Waveguide

A microfluidic analysis system integrated with liquid-liquid extraction and liquid-liquid waveguide detection was explored. Multiphase laminar liquid-liquid extraction was realized using 1-butyl-3-methyl imidazolium bromide ionic liquid/sodium carbonate solution aqueous two. phase system. Liquid-liquid waveguide absorption photometric detection was achieved by the ionic liquid with higher refractive index served as liquid core and the salt aqueous solution with lower refractive index served as liquid cladding. The extraction efficiency for cresol red extraction is more than 93%. The linear range, the relative standard deviation and the detection limit for cresol red detection were 0. 01-0. 40 mg/mL, 3. 4%(n = 11) and 3. 8 mu g/mL (3 sigma) respectively. Extraction separation and liquid-liquid waveguide-based long optical path absorbance detection were integrated in the system, which provided a new strategy for expanding the application of absorbance detection in microfluidic systems.