Mirella Rosa

Nicotine, cotinine, and trans-3-hydroxycotinine levels in seminal plasma of smokers: Effects on sperm parameters

Sperm samples from 44 cigarette smokers and 50 nonsmokers attending an infertility clinic were examined by high-performance liquid chromatography (HPLC) assay and HPLC-mass spectrometry for the presence of nicotine (NIC), cotinine (COT), and trans-3‘-hydroxycotinine (THOC) in seminal plasma. Smokers were found to have levels of COT and THOC in seminal plasma that were similar to those found in serum. The level of NIC was significantly increased in seminal plasma compared to serum. Total motility of spermatozoa was significantly and negatively correlated to COT and THOC levels in seminal plasma. Forward motility of spermatozoa was correlated only with cotinine semen levels. On the basis of these results, we suggest that the presence of tobacco smoke constituents in seminal plasma could provide a warning of the adverse effects of cigarette smoke on the physiology of reproduction.

How the steady‐state cotinine concentration in cigarette smokers is directly related to nicotine intake

The relationship between nicotine intake and steady‐state cotinine concentration was studied in a sample of 125 subjects who smoked their usual brands of cigarettes. Nicotine and tar yield of cigarettes was determined with a smoking machine, under standardized conditions. Blood was drawn about 8 hours after the last cigarette was smoked and serum cotinine was measured by high performance liquid chromatography. Cotinine levels ranged from 11 to 400 ng/ml, and nicotine daily intake ranged from 1 to 33 mg/day. Regression analysis and the correlation coefficient, r = 0.919, significant at p < 0.0001, showed that steady‐state cotinine level was linearly and directly related to daily available nicotine, with an increase in correlation coefficient directly related to the increase in tar and nicotine yield. From the findings we also conclude that smokers of low‐tar cigarettes do not tend to compensate for lower yields of nicotine.

Use of solvent optimization software for rapid selection of conditions for reversed-phase high-performance liquid chromatography of nicotine and its metabolites

Abstract Solvent optimization software was used to develop a reversed-phase HPLC method for nicotine, five of its metabolites and caffeine under isocratic conditions, using UV detection and a LC8DB reversed-phase column. Starting from a methanol-buffer gradient, the software helped to find a quaternary solvent composition consisting of 2.3% methanol, 4.3% acetonitrile, 0.3% tetrahydrofuran and 93.1% buffer for the separation. The method was applied to human spiked serum and to serum of 12 cigarette smokers using a simple purification treatment before chromatography.

Elimination of caffeine interference in high-performance liquid chromatographic determination of cotinine in human plasma.

A high-performance liquid chromatographic method with ultraviolet photometric detection for the determination of cotinine in human plasma was described. The use of a 30-cm reversed-phase column and of a mobile phase consisting of water-methanol-0.1 M sodium acetate-acetonitrile (72:21:5.6:1.4, v/v), pH 4.1, eliminated caffeine interference. A simplified solid-phase extraction procedure was also performed for plasma samples.