GC-AED studies of nicotine fate in a burning cigarette

An atomic emission detector (AED) for a gas chromatograph (GC) can be used to selectively detect compounds labeled with stable isotopes, such as D, C- 13, and N-15. This capability can be used to determine precursor-fate relat ionships within complex matrices, using stable isotopes rather than radiola beled isotopes. Employing stable isotopes removes the safety consideration associated with radiolabeling studies. Two previous reports have employed G C-AED in fate studies for C-13-labeled precursors. The goal of this study w as to evaluate the utility of GC-AED for precursor-fate determinations in t obacco science; In this work, GC-AED was used to determine the fate of nico tine-d(4) in a burning cigarette. GC-MSD was then: employed to identify the compounds that the AED indicated contained D. Spectral confirmation of the presence of D was performed on each chromatographic peak of interest with both AED and MSD to ensure that the identification of the products was corr ect Nicotine and nicotine-de standards were used to evaluate the effect of coelution of unlabeled compounds with the labeled compounds on the AED resp onse for D. It was shown that the AED response for D at lambda = 308 nm dec reases with increased concentration of unlabeled compound. Detection at lam bda = 656 nm, however, is unaffected by the presence of the unlabeled compo und. Compound-independent calibration is also possible at this wavelength. GC-AED studies with nicotine-d(4) core injected into cigarettes demonstrate d that most of the nicotine (79%) is distilled; unchanged, into the mainstr eam (MS) and sidestream (SS) smoke. The degradation products that do occur include 3-substituted pyridines and nicotine-oxidation products. These are found only in the SS smoke.