Historical perspective Analytical luminescence can be traced to the initial observations of the Span- ish botanist and physician Nicolas Monardes. In 1665 Monardes noted that water contained in a cup made from a specific wood (Ligiriu nephi- ticiem) exhibited an odd blue shimmer During the next century, eminent scientists such as Robert Boyle also ob- served this unknown" phenomenon. In 1833 Sir David Brewster recognized a red emission from green leaf extracts. Although he first attributed the color to some type of dispersive scattering phenomenon, today we know this char acteristic emission as fluorescence from chlorophyll. In 1845 Herschel recorded the first "fluorescence emission spectrum" of quinine. He also recognized that the sample was excited in the blue region of the spectrum more than in the green or red regions. However, it was not until 1852 that George Stokes determined that the emission from quinine was at a longer wavelength than the excitation, a difference that bears Stokes's name. In addition to coining the term fluores- cence, Stokes was the first to propose the use of fluorescence as an analytical tool. In 1867 Goppelsroder was the first to perform a fluorescence-based analysis. He developed a method for the quanti- tation of nonluminescent Al (III) by forming a strongly fluorescent morin: Al(III) complex. Still further evidence of the power of luminescence was demonstrated in 1877, when Adolf Baeyer used fluores cence to demonstrate a link between