Hair analysis of nicotine and cotinine for evaluating tobacco smoke exposure by liquid chromatography-mass spectrometry.

A simple liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) method for the determination of nicotine and cotinine in human hair was established. In the procedure, a hair sample (10 mg) was washed with dichloromethane and digested in 2.5 M sodium hydroxide. The digest was extracted with dichloromethane and then 25 mM hydrochloric acid in methanol was added to the extract, to prevent loss of analytes. The solution was evaporated and redissolved in the mobile phase, methanol/10 mM ammonium acetate (30/70, v/v). A 20 microL aliquot of redissolved solution was subjected to analysis. Nicotine and cotinine in human hair were quantified by using deuterated analytes as internal standards. The quantification limits were 8 microg/L for nicotine and 0.9 microg/L for cotinine. The proposed method was applied to measure the concentrations of nicotine and cotinine in hair of smokers and non-smokers to evaluate their self-reported smoking and exposure to environmental tobacco smoke. In both cases, the method provided good selectivity, accuracy and precision.

Chetiyanukornkul T ，Toriba A ，Kizu R ，Kimura K ，Hayakawa K ... -  《BIOMEDICAL CHROMATOGRAPHY》

Analysis of nicotine and cotinine in hair by on-line in-tube solid-phase microextraction coupled with liquid chromatography-tandem mass spectrometry as biomarkers of exposure to tobacco smoke.

Smoking not only increases the risk of lung cancer but is strongly related to the onset of cardiovascular disease. Particularly, passive smoking due to sidestream smoke is a critical public health problem. To assess active and passive exposure to tobacco smoke, we developed a simple and sensitive method, consisting of on-line in-tube solid phase microextraction (SPME) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS), to determine nicotine and its metabolite cotinine in hair samples. These compounds were separated within 5 min using a Polar-RP80A column and detected in the positive ion mode by multiple reaction monitoring. The optimum in-tube SPME conditions were 25 draw/eject cycles of 40 μL of sample at a flow rate of 200 μL/min using a Carboxen 1006 capillary column as an extraction device. The extracted compounds in the stationary phase on the inner wall of the capillary could be dissolved easily into the mobile phase and transferred to an LC column. Using the in-tube SPME LC-MS/MS method, the calibration curves were linear in the 5-1000 pg/mL ranges for nicotine and cotinine, and the detection limits (signal to noise ratio of 3) were 0.45 and 0.13 pg/mL, respectively. The intra-day and inter-day precisions were below 3.4% and 6.0% (n = 5), respectively. This method was utilized successfully to analyze pg/mg levels of nicotine and cotinine in 1 mg of hairs without interference peaks, and good recoveries were obtained. The concentration of cotinine in hair was two orders of magnitude lower than that of nicotine, but a good positive correlation was found between the concentrations of these compounds. This method can automate the extraction, concentration and analysis of samples, and is useful for the assessment of long-term exposure to tobacco smoke.

Inukai T ，Kaji S ，Kataoka H 《-》

Risk Assessment of Passive Smoking Based on Analysis of Hair Nicotine and Cotinine as Exposure Biomarkers by In-Tube Solid-Phase Microextraction Coupled On-Line to LC-MS/MS.

Kataoka H ，Kaji S ，Moai M 《MOLECULES》

[Detecting Nicotine and Cortinine in Hair by Hydrophilic Interaction Liquid Chromatography Tandem Mass Spectrometry].

To develop a method for detecting nicotine and cotinine in hair by hydrophilic interaction chromatography tandem mass spectrometry. Hair samples were hydrolyzed in sodium hydroxide solution before extraction with dichloromethane. The samples were blown to dry with nitrogen and dissolved with mobile phase. The filtrate of the samples was injected into a chromatographic-mass spectrometry system for analysis. The separation was performed by a hydrophilic column, with which methanol-0.1% ammonia was used as the mobile phase. The quantitative detection of Nicotine and Cortinine was carried out with electron spray ionization-triple quadrupole mass spectrometry. The established method was used for detecting nicotine and cotinine in 602 hair samples of pregnant women and 31 hair and urine samples of volunteers. A standard curve was drawn for the established method of hydrophilic liquid chromatography tandem mass spectrometry. Good linearity was obtained for detecting nicotine and cotinine in the range of 0.030-100.000 μg/L, with a detection limit (MDL) of 0.007 6 μg/g and 0.004 4 μg/g, respectively. The inter-day and intra-day precisions reached a level of less than 10%. The recoveries of the spiked samples ranged from 81.0% to 102.0%. About 0.020-0.260 μg/g nicotine and 0.004 8-0.069 0 μg/g cotinine were detected in the pregnant women without exposure to secondhand smoking (SHS), compared with 0.029-0.350 μg/g nicotine and 0.005 6-0.085 0 μg/g cotinine in those exposed to SHS. Nicotine and cotinine were also found in the hair and urine samples of volunteers, which were correlated with smoking (P < 0.05). A dose-response relationship were found between smoking and hair nicotine. The proposed method is accurate and sensitive for detecting nicotine and cotinine in hair samples. Hair nicotine can be a specific biomarker for assessing exposure to tobacco smoking.

Zhu J ，Ren JW ，Yang MQ ，Wang Y ，Liu X ，Zou XL ... -  《-》

Hair nicotine/cotinine concentrations as a method of monitoring exposure to tobacco smoke among infants and adults.

Tzatzarakis MN ，Vardavas CI ，Terzi I ，Kavalakis M ，Kokkinakis M ，Liesivuori J ，Tsatsakis AM ... -  《-》