DETERMINATION OF NICOTINE BY SURFACE-ENHANCED RAMAN-SCATTERING (SERS)

The analytical application of surface-enhanced Raman spectroscopy (SER S) to the determination of nicotine is demonstrated. A simple spectroe lectrochemical method using a copper or silver electrode as the SERS s ubstrate has been developed, consisting of three steps: polishing a wo rking electrode to a mirror finish; roughening the electrode in an ele ctrolyte solution; and, finally, depositing the nicotine analyte onto the roughened electrode after immersion in a sample solution. During t he reduction cycle, a large enhancement in nicotine Raman scattering i s observed at the electrode surface. The intensity of the SERS signal on a silver electrode is linear with concentration from 10 to 900 ppb, with an estimated detection limit of 7 ppb. The total analysis time p er sample is approximately five minutes. This procedure has been used to analyze the extract from a cigarette side-stream smoke sample (envi ronmental tobacco smoke); the SERS results agree well with those of co nventional gas chromatographic analysis.