Development of Tetrahydrofuran/Water Optical Waveguide and Its Application to the Observation of Extraction Behavior of l-Anilino-8-naphtalene Sulfonate at the Tetrahydrofuran/Water Interface

Abstract

A stable two-phase sheath flow using tetrahydrofuran (THF) for an inner flow and water for an outer flow was formed in a glass capillary, and worked as a stable liquid-core/liquid-cladding optical waveguide (THF/water LLW). Although THF and water were miscible with any ratio, the length of the stable THF/water LLW at 0.9 -2.1 cm s -1 reached at least 150 mm. The THF/water LLW was applied to the observation of extraction behavior of solvatochromic fluorescence dye, 1-anilino-8-naphtalene sulfonate (ANS), through the THF/water interface. ANS was added to the water phase (clad solution) and its fluorescence, which was excited with the guided light (355 nm) through the LLW, was observed by changing the position of the detector. While the ANS stayed in the region of 70% THF to the end of the LLW without the addition of cationic surfactant, hexadecyltrimethylammonium ion (CTA + ) at pH 3 and 11, the ion-pair of ANS and CTA + was extracted into the higher concentration region of THF with the addition of CTA + at pH 11.

A Dual Alkylated Peptide-ligand Enhances Affinity to Human Serum Albumin

“…ANS is basically non-fluorescent in aqueous media but shows strong fluorescence upon binding to the hydrophobic pocket of HSA. [15][16][17] Thus, the replacement of ANS bound to HSA with ligands causes quenching of the ANS fluorescence. It has been reported that subdomain IIIA and IIA of HSA have the binding pockets of ANS to provide fluorescent property to ANS.…”

Application of D-Limonene as a Bio-based Solvent in Low DensityDispersive Liquid?Liquid Microextraction of Acidic Drugs from Aqueous Samples

“…10 These drawbacks have attracted attention to new miniaturized sustainable techniques and/or solvents like DLLME introduced by Rezaee. 11 It was combined with chromatographic techniques for organic [12][13][14][15][16][17] and inorganic [18][19][20][21][22][23][24] compounds analysis in environmental, pharmaceutical, and biological samples. However, not only reducing the volume of used organic solvents, but also replacing hazardous solvents with greener ones is required.…”

A Liquid-core Liquid-cladding Optical Waveguide Based on Thermal Gradients across the Laminar Flow of Water in Capillary Tubing

“…Recently, liquid-core/liquid-cladding optical waveguides (LLWs), whose concept was firstly introduced by us, [1][2][3][4] have widely been studied as a key element of optofluidics. [5][6][7][8][9][10][11][12] LLWs are usually built using two kinds of miscible liquids that have different refractive indices such as 50% ethanol/water, 5% NaCl aqueous solution/water and etc.…”