Flow injection Fourier transform infrared determination of nicotine in tobacco.
A fully automated procedure is proposed for the Fourier transform infrared (FTIR) determination of nicotine in tobacco. The method is based on the on-line extraction of nicotine with CHCl3. Samples, weighed inside empty extraction cartridges, were humidified with NH3 and the cartridges were installed in a flow manifold in which they were extracted with 2 ml CHCl3 for 2 min, then 400 microliters of the extract were introduced into a micro-flow cell using a carrier of CHCl3 and the IR spectrum was registered continuously. The absorbance, in the wavenumber range 1334-1300 cm-1, was measured, obtaining a peak as a function of time. The area of this peak was interpolated on a calibration line established from standard solutions of nicotine in chloroform treated in the same way as samples. The method provided a limit of detection of 0.1 mg ml-1 nicotine, an RSD lower than 2% and a sampling frequency of the whole procedure of 6 h-1. Results obtained for natural samples of cut tobacco and cigar compared well with those obtained by a batch FTIR procedure, involving an off-line extraction with a total time of 16 min. However, for yellow tobacco cigarette, an on-line extraction time of 10 min was required to obtain a good recovery of nicotine.
Garrigues
J M
JM
Department of Analytical Chemistry, University of Valencia, Burjasot, Spain.
Pérez-Ponce
A
A
Garrigues
S
S
de la Guardia
M
M
D017022:Flow Injection Analysis / Q000379:methods; D005583:Fourier Analysis; D006801:Humans; D009538:Nicotine / Q000032:analysis*; D010947:Plants, Toxic; D014026:Nicotiana / Q000737:chemistry*
D009538:Nicotine