DETERMINATION OF ORGANICS ON METAL-SURFACES BY RAMAN-SPECTROSCOPY

Detection limits of about 1 g/m2 are demonstrated for the Raman determ ination of two organic materials, polydimethylsiloxane and dimethyl me thylphosphonate, on an aluminum surface. A fiber-optic-based system is used. A large sample area is scanned to overcome heterogeneity in sam ple coverage. Measurements are made without use of an internal standar d. Results are reported for both a Hadamard transform technique with a rgon-ion laser excitation and a conventional spectrometer with diode l aser excitation.