engleski

Optimisation of a solid-phase microextraction method for analysis of nicotine in hair

Nicotine and its main metabolite cotinine are widely used as biomarkers of environmental tobacco smoke (ETS) exposure and they can be determined in various bilogical specimens. Analysis of nicotine in human hair provides information on exposure to ETS over a longer period of time (each 1 cm of hair represents appoximately one month's exposure) in contrast to serum, urine, and saliva analyses which reflect the last few days exposure to ETS (1). The aim of the present study was to develop a simple, sensitive, and fast method for determination of nicotine in nonsmokers' i.e. passive smokers' hair. The method is based on headspace solid-phase microextraction (HS-SPME) as the sample preparation method, and gas chromatography combined with mass spectrometry detection as determination technique. The main parameters affecting the microextraction process such as type of fiber coating, extraction mode, amount of hair, extraction temperature and time, stirring, and salt addition were optimised. Polyacrylate (PA) 80 micrometer fiber was used in the headspace mode to extract nicotine from 25 mg of hair samples, with addition of 1 ml NaOH and 0.5 g NaCl. After the sample extraction (15 min at 80^oC), analytes were thermally desorbed in the GC injector for 5 min at 280^oC and transferred into the column. The method provided good linearity (r^2>0.9980) over the concentration range tested (0.5-20 ng/mg) and low detection limit (0.02 ng/mg). Repeatability expressed as relative standard deviation was <10 %. The average recovery was 95 %. The optimised method was applied for the quantitative analysis of nicotine in hair samples collected from 25 passive smokers. The concentrations of nicotine ranged from 0.52 to 12.54 ng/mg. The described HS-SPME procedure is fast, simple, sensitive and solvent-free method and therefore suitable for studies involving ETS exposure assessment. (1) W.K. Al-Delaimy, J. Crane, A. Woodward, J. Epidemiol. Community Health 56(2002)66.

Hair; nicotine; passive smokers; SPME

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