Patent ID: 7393692

Claim:
A method for the analysis of the saliva of a subject by surface-enhanced Raman spectroscopy to enable determination of the presence and concentration therein of at least one drug species, comprising the steps: obtaining a small sample of saliva; treating said sample of saliva to effect mutual separation of said drug species and interfering chemicals present in said sample, to produce an analyte sample containing said at least one drug species, said sample treatment including a physical treatment utilizing separation means for removing molecules of 10,000 molecular weight or higher; thereafter combining said treated analyte sample with a SERS-active metal-containing material of porous structure and of different character from said separation means; subjecting said combined treated analyte sample and SERS-active material to SERS to generate a SERS spectrum; analyzing said SERS spectrum to determine the presence and concentration of said at least one drug species in said analyte sample, said steps being repeated sequentially, a multiplicity of times at intervals throughout a time period of 20 minutes or longer, using the saliva of said subject; and utilizing information as to the presence and concentration of said at least one drug species in said analyte sample, so determined by said steps so repeated, to in turn determine changes in said concentration of said at least one drug species during said time period and thereby to determine the pharmacokinetics or the extent of metabolism of said at least one drug species.