Fluorescence is a type of electromagnetic spectroscopy that employs emission from a sample. It involves using a beam of light that excites the electrons in specific compounds and causes them to emit light of a lower energy. As proof of principle, a computer controlled experiment is described employing a single microliter capillary tube setup, using a two wavelength excitation of a single wavelength emission of hydroxypyrene trisulfonate. The same setup can be manipulated for the other pH-sensitive fluorescence ratiometric systems. In addition, this setup can be scaled up for high-throughput measurements.