4, 4′-Diamino-4"-methoxytriphenylamine as highly sensitive fluorimetric sensor for the determination of water in organic solvents

In this work, we report fast and low-cost fluorimetric system for the determination of trace amounts of water in both aprotic and protic organic solvents. The analytical signal of the proposed method is based on the quenching effects of water on the fluorescence emission spectrum of (4, 4 '-diamino-4 ''-methoxytriphenylamine) molecule. It was found that physical interactions such as hydrogen bonding are responsible for the observed quenching effect. The limit of detection values for the determination of water in DMSO, acetonitrile, ethanol and methanol were 0.0727, 0.0636, 0.0761 and 0.0631 (W/W%), respectively. The limit of quantitation values in DMSO, acetonitrile, ethanol and methanol were 0.2734, 0.2546, 0.2540 and 0.2531 (W/W%), respectively. Simplicity, low cost and high speed of the proposed water sensing system make it a valuable candidate to be used in industrial applications such as quality control procedures. In addition, it can be used for the determination of water in redox active solvents such as DMSO, where the standard Karl Fischer method gives problematic results.