FIBEROPTIC MULTIPHOTON IONIZATION DETECTION OF POLYCYCLIC AROMATIC-HYDROCARBONS

A fiber-optic multiphoton ionization detector was constructed. A pair of gold electrodes was fixed at the end of a fused-silica glass fiber of 1 mm diameter, and this end was dipped into a sample solution. Pulsed laser light at 355 nm was introduced into the fiber, and the current resulting from the two-photon ionization of an analyte was measured and analyzed. The detection limits for several polycyclic aromatic hydrocarbons were determined; the lowest was 0.12 ng ml-1 for anthracene and 9, 10-dimethylanthracene. The laser power could be very low.