Detection of trace amounts of water in organic solvent by 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt

A colorimetric and fluorescent sensor was developed based on 8-hydroxy-1,3,6-pyrenetrisulfonic acid trisodium salt (HPTS) for the detection of trace amounts of water in polar organic solvents. Fluorescence and UV-visible absorption spectra of HPTS were measured in a variety of organic solvents (DMF, DMSO, ethanol, methanol). Fluorescence maxima comparable with maximum/minimum ratios were determined by using UV-visible absorption spectroscopy. The HPTS sensor exhibits high sensitivity for water with a detection limit as low as 0.0001 to 0.0005wt-%. In addition, naked-eye inspection of solutions of HPTS sensor in organic solvents before and after addition of water showed dramatic changes in colour from blue to green. These findings can be applied in the use of HPTS as a molecular probe for trace amounts of water in organic solvents.