[Nicotine in the hair as a biomarker of tobacco smoke by pregnant women--preliminary study].Przegl Lek. 2007; 64(10):729-33.PL
Determination of xenobiotics in hair has become common in evaluation of exposure to drugs. It can be used to assess the drug intake among adults and exposure to these substances in prenatal period. The aim of this study was the nicotine determination in hair of newborns' whose mothers were smoking during pregnancy. Also the relationship between concentration of cotinine--the main metabolite of nicotine in the urine of mothers and nicotine concentration in their infants' hair has been evaluated. The group of 15 women who had been smoking during pregnancy and 10 non-smoking and not exposed to ETS women and their newborns were the subject of the study. The cotinine levels in maternal urine samples was measured by the high performance liquid chromatography (HPLC) with a spectrometric detection, with the use of norephedryne as an internal standard, after a prior extraction with the use of liquid-liquid technique. Nicotine assess in infants' hair was carried out by means of gas chromatography coupled with mass spectrometry, with the use of ketamine as an interior standard, after the prior extraction with the use of liquid-liquid technique. The mean cotinine concentration in the group of smoking women amounted to 1132.5+/-1236.3 ng/mg creatinine and the level of nicotine in hair of children amounted to 1.9+/-3.2 ng/mg of hair. In the group of non-smoking women the urine cotinine test showed that two patients were exposed to the tobacco smoke. Nicotine in their children's hair was below the detection limit. The demonstrated correlation between the nicotine concentration in infants' hair and the cotinine levels in mothers' urine shows that the source of fetal exposure to tobacco smoke constituents is smoking during pregnancy. The applied gas chromatography method/mass spectrometry method allows to evaluate the level of nicotine in hair of the newborns, whose mothers were smoking during pregnancy, however it seems that in the case of exposure to ETS a more sensitive method, such as gas or liquid chromatography coupled with tandem mass spectrometry has to be applied.