A novel validated procedure for the determination of nicotine, eight nicotine metabolites and two minor tobacco alkaloids in human plasma or urine by solid-phase extraction coupled with liquid chromatography-electrospray ionization-tandem mass spectrometry

Gas chromatography-mass spectrometry determination of nicotine and cotinine in urine: A study of the effect of passive smoking

RATIONALE

Recent data suggest that passive smoking has a risk comparable to active smoking. Passive smoking is considered dangerous in children and is suspected as a cause of asthma. However, some reports are opposing such claims, indicating the need for solid results and large-scale studies. This scientific work aims to develop a method for the determination of nicotine (NCOT) and major nicotine's metabolite cotinine (COT) in urine samples, using gas chromatography-mass spectrometry (GC-MS).

METHODS

Analysis was performed using a gas chromatograph Agilent Technologies 7890A with an MS 5975C inert XL, EI/CI MSD with Triple-Axis detector. For sample preparation, liquid-liquid extraction was applied after an optimization study with different extraction media. Eventually, 1 mL of dichloromethane was selected for the extraction of 0.5 mL of urine. Suitable chromatographic conditions were found for the rapid and accurate determination of NCOT and COT. Injection of 2 μL was performed using GC-MS, and selected ion monitoring (SIM) analysis was performed with the following ions (m/z): 162 (quantifier ion) and 84, 133, 161 qualifier ions for NCOT, and 176 (quantifier ion) and 98, 118, 119, 147 qualifier ions for COT. Nicotine-D4 (NCOT-D4) and cotinine-D3 (COT-D3) were used as internal standards with quantifier ions 101 and 166, respectively. The retention time (Rt) for NCOT was 7.557 min and 9.743 min for COT.

RESULTS

The method was validated following international principles, assessing characteristics such as absolute recovery, carryover, linearity, specificity, selectivity, accuracy, precision, and stability. The method showed a linear dynamic range from 0.5 to 50 ng/mL, and the limits of detection and quantification were for both NCOT and COT 0.2 and 0.5 ng/mL, respectively. Validation results were found satisfactory. Finally, the method was applied to the analysis of 60 clinical pediatric samples obtained from Aristotle University's pediatric clinic to check for possible exposure to smoke. Concentration levels ranged between 0.5 and 16.2 ng/mL for NCOT and between 1.0 and 25.1 ng/mL for COT.

CONCLUSIONS

A rapid, sensitive, accurate, and simple method was developed and used as a tool for the confirmation of passive smoking in children. It is the first method applied to the analysis of such samples belonging to nonsmokers of young age. The total runtime of the GC-MS analysis was short (20 min), and the pretreatment protocol was simple, giving the ability for analysis of a large number of samples on a daily routine basis.

Quantitation of Urine Nicotine, Cotinine, and 3-OH-Cotinine by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Nicotine is a naturally occurring and highly addictive chemical used in e-cigarettes, cigarettes, chewing tobacco, and other tobacco products as well as in nicotine replacement therapies. The negative health consequences of using nicotine-containing products are well known. In fact, smoking remains the leading cause of preventable disease, disability, and death in the United States. Measurement of nicotine and its metabolites, cotinine and 3-OH-cotinine, offers an objective method to evaluate nicotine exposure and the associated health risks. In this chapter, we describe a quick and reliable isotope dilution LC-MS/MS method for the quantitation of these three compounds in 60 μL of human urine following a simple sample preparation procedure. Electrospray Ionization (ESI) in positive mode is used to introduce the analytes into the mass spectrometer and quantitation is achieved using Multiple Reaction Monitoring (MRM). The analytical measurable ranges for nicotine and cotinine are 10-2500 ng/mL and 20-5000 ng/mL for 3-OH-cotinine.

Nicotine consumption rate through wastewater-based epidemiology: a systematic review, meta-analysis and probabilistic risk assessment

Wastewater-based epidemiology (WBE), as a rapid tool, is used to measure and monitor illicit drug consumption in the population. This method is also used to bridge biomarkers of exposure, contaminants, and human health. Smoking cigarettes and tobacco use are everyday habits in nowadays community. This systematic review and meta-analysis aimed to calculate nicotine consumption globally. The related studies were retrieved within international databases including Scopus, Google Scholar, and Web of Science, up to February 2021. It included twenty-one articles containing 87 measurements covering 275.3 million people with total wastewater samples of 2250. Results showed that the highest and lowest nicotine consumption rate (mg/1000 inh./day) was in Portugal (5860) and Vietnam (1201), respectively. The global pooled nicotine consumption rate was 2476 mg/1000 inh./day (95% CI (2289-2663). Based on WBE results, the average daily cigarette smoked per smoker is 14 (95% CI: 10-18 cigarettes/inh./day), close to the value of 14.2 reported by the survey and interview studies. Risk assessment of the nicotine consumption rate through WBE was calculated by the margin of exposure (MOE) approach. In total, 82% of nicotine consumption measurements were located in the "risk" level (MOE < 100), and 18% of the MOE values were between 100-1000. The results reveal that nicotine consumption risks need immediate global and local action strategies. Finally, these findings are helpful for healthcare agencies and policy-makers to take action against tobacco use prevalence.

Determination of nicotine content in locally produced smokeless tobacco (Shammah) samples from Jazan region of Saudi Arabia using a convenient HPLC-MS/MS method

Shammah is one of the forms of smokeless tobacco (SLT) prepared by mixing tobacco powder with other ingredients to increase its acceptability. Nicotine (NT) is the main alkaloid present in tobacco and is a precursor for carcinogenic metabolites including tobacco specific nitrosamines (TSNAs). In this study, eight varieties of Shammah samples, collected from Jazan region of Saudi Arabia, were analyzed for NT content by a validated high performance liquid chromatography-mass spectrometry/mass spectrometry method. Electrospray ionization was used with the multiple reaction monitoring in the positive mode for data acquisition. The method was fast and short retention times (RT) of 1.4 and 3.1 min were observed for NT and lapatinib used as internal standard (IS), respectively. The inter- and intra-day accuracy and precision results met the acceptance criteria of United States Food and Drug Administration and International Council for Harmonisation validation guidelines. The developed method was successfully applied for the detection of NT contents in various Shammah samples. NT concentration was found to be in the range of 6.94 ± 0.16 to 31.69 ± 0.79% with the maximum level detected in special Shammah from Ahad Al Masarihah and the lowest level in Khadrah Shammah from Samtah city. The results of this investigation have warranted further research to determine the minor Shammah contents including additive materials and assessment of associated health effects.

Passive Smoking Exposure Modifies Cardiovascular Structure and Function: Beijing Child Growth and Health Cohort (PROC) Study

Passive smoking exposure in children is prevalent worldwide and exposes children to respiratory and systemic toxins. In this study, we enrolled 568 children to study how secondhand smoke (SHS) might affect children's cardiovascular health in China. The measurement of nicotine and its metabolites in urine showed that 78.9% of children were exposed to SHS. Children exposed to SHS had greater interventricular septum thickness (p = 0.005) and left ventricular mass index (p = 0.008) than nonexposed children. Urinary norcotinine levels were associated with increased ascending aorta diameter (β = 0.10, 95%CI 0.02-0.17) and decreased left ventricular end systolic diameter (β = -0.10, 95%CI -0.19 to -0.01). The effects of SHS exposure on cardiovascular function: norcotinine levels associated with lower left ventricular mass index (β = -0.32, 95%CI -0.59 to -0.05), left ventricular end diastolic volume index (β = -0.43, 95%CI -0.85 to -0.02), and left ventricular end systolic volume index (β = -0.20, 95%CI -0.37 to -0.03). Moreover, there no no significant associations of nicotine, cotinine, and trans-3'-hydroxycotinine with cardiovascular health. Overall, SHS exposure in children remains prevalent in Beijing and may affect children's cardiovascular development, in both structure and function. It suggests that stricter and practical measures are needed toward the elimination of tobacco use in children's environments.

Development of an Ultra-High Performance Liquid Chromatography method for the simultaneous mass detection of tobacco biomarkers in urine

The quantification of tobacco exposure biomarkers is relevant to follow the patients' tobacco use. They allow to discriminate between tobacco users, non-users, passive smokers, and nicotine products users, such as in nicotine replacement therapy. The aim of this study was to develop and validate a quantification method of tobacco biomarkers of choice - nicotine, cotinine, trans-3'-hydroxycotinine, anatabine and anabasine - in urine. The challenge was to develop an easy and rapid liquid chromatography method requiring only one extraction step and allowing simultaneous detections. Some methods are described in the literature but need specific investment in terms of instrumentation and users training. Here, the developed method had to be carried out with instrumentation easily accessible for medical laboratories. The extraction of the analytes was performed by Supported Liquid Extraction (SLE), which consists in liquid-liquid extraction but supported by a sorbent. It allows to insure efficient neutrals extraction with less organic solvent and without any emulsion formation. 200 µl of basified urine - analytes of interest are neutral in this condition - were loaded on Novum SLE 96-Well Plates (Phenomenex) and analytes were eluted with 1 % formic acid in dichloromethane/propan-2-ol (95/5). After solvent evaporation, samples were reconstituted with 100 µl of water for injection. A mass detector (QDa, Waters) was used to detect analytes, this pre-optimised quadrupole mass analyser being less expensive and requiring less adjustments than traditional mass spectrometers while benefiting of the reliability of mass spectral data. This detector was integrated after an Ultra-high performance liquid chromatography (UHPLC) separation on a BEH C18 column (Waters) at a flow rate of 0.5 ml/min. A gradient elution of H₂O (pH 10 with NH₄OH) and CH₃CN was used. Finally, the developed method was validated. This new method is conclusive to assess the patients' tobacco exposure and is easy to implement in medical laboratories.

Characterization of molecularly imprinted polymers for the extraction of tobacco alkaloids and their metabolites in human urine

Molecularly imprinted polymers (MIPs) are synthetic polymers designed to selectively extract target analytes from complex matrices (including biological matrices). The literature shows that MIPs have a degree of cross-selectivity from analytes within the same class of compounds. A commercially available MIP for tobacco-specific nitrosamines (TSNAs) is designed to be class selective for four TSNA compounds. This study sought to characterize the extent of cross-selectivity of the TSNA MIPs with other tobacco alkaloids. Cross-selectivity and recovery of the SupelMIP™ TSNA SPE cartridges was assessed with N-nitrosonornicotine (NNN), nicotine, cotinine and morphine. Their recoveries were compared with the recoveries of a nonimprinted polymer SPE cartridge, and two traditional SPE cartridges: a Waters mixed-mode cation exchange cartridge and a Waters hydrophilic-lipophilic balance cartridge. NNN and cotinine had the highest recoveries with the MIP cartridge, over 80%, and cotinine samples in urine had >80% recoveries. Nicotine had highly variable recoveries, possibly owing to differing chemical properties from the TSNAs. All three analytes had significantly different recoveries with the MIP cartridges compared with the traditional SPE cartridges. Morphine displayed nonspecific interactions with the MIP cartridges. Utilization of the TSNAs' cross-selectivity allows for simultaneous extraction and identification of multiple tobacco biomarkers using one extraction technique.

Association between Fathers’ Use of Heated Tobacco Products and Urinary Cotinine Concentrations in Their Spouses and Children

Heated tobacco products (HTPs) have become increasingly popular among smokers, especially among young adults in Japan in recent years. Assessments of secondhand tobacco smoke (SHS) exposure due to HTPs are scarce. The present study aimed to assess the urinary levels of total nicotine metabolites (TNMs) of non-smoking spouses and their children following SHS exposure due to their fathers’ use of HTPs. A total of 41 families including 129 participants were recruited between 2018 and 2021. The number of non-smoking spouses and children of the fathers who smoke combustion cigarettes, the fathers who use HTPs, and the fathers who are non-users or have never smoked was 27, 66, and 36, respectively. The urinary levels of TNMs, including cotinine (Cot) and 3′-hydroxycotinine (3-OHCot), were measured using liquid chromatography/tandem mass spectrometry (LC/MS/MS). The spouses and children of fathers who use HTPs had significantly higher levels of TNMs in their urine compared to those with fathers who were non-smokers or non-users. The current study is the first to assess SHS exposure due to HTP use, and to suggest the importance of strategies to prevent exposure to SHS from HTP use in public places and educational strategies to protect non-smokers from secondhand HTP aerosol exposure in households and other private places.

Identification of potential biomarkers in urine and plasma after consumption of tobacco product in horses

The use of nicotine stimulants in horses is generally banned in horse racing and equestrian sports-accidental consumption of tobacco products is one of the possible causes of nicotine exposure in horses. The authors recently reported a comprehensive metabolic study of nicotine in equines, differentiating between nicotine exposure and sample contamination by means of a nicotine biomarker trans-3'-hydroxycotinine. To identify potential biomarkers for the differentiation of genuine nicotine administration and consumption of tobacco products, tobacco leaves (equivalent to 250 mg of nicotine) were nasoesophageally administered to three thoroughbred mares. Quantification methods of anatabine in plasma and urine were newly developed and validated and successfully applied to post-administration samples. Previously reported simultaneous quantification methods of eight target analytes including nicotine and its metabolites in plasma and urine were also applied to the samples. The results demonstrate that both trans-3'-hydroxycotinine and anatabine could be used as potential biomarkers in equine urine and plasma to indicate recent exposure to tobacco products in horses. As well, trans-3'-hydroxycotinine had the longest half-life as a detectable metabolite in urine and plasma. To our knowledge, this is the first report of a comprehensive study of tobacco product detection in horses.

Review of HPLC-MS methods for the analysis of nicotine and its active metabolite cotinine in various biological matrices

In recent years, tobacco smoking is a risk factor for a series of diseases including cardiovascular diseases, cerebrovascular diseases, and cancers. Nicotine, the primary component of tobacco smoke, is mainly transformed to its active metabolite cotinine, which is often used as biomarker for tobacco exposure for its higher blood concentration and longer residence time than nicotine. Various analytical methods have been developed for the determination of nicotine and cotinine in biological matrices. This article reviewed the HPLC-MS based methods for nicotine and/or cotinine analysis in various biological matrices. The sample preparation, mass and chromatographic conditions and method validation results of these methods have been summarized and analyzed. Sample was mainly pretreated by protein precipitation and/or extraction. Separation was achieved using methanol and/or acetonitrile:water (with or without ammonium acetate) on C18 columns, and acetonitrile:water (with formic acid, ammonium acetate/formate) on HILIC columns. Nicotine-d3, nicotine-d4 and cotinine-d3 were commonly used internal standards. Other non-deuterated IS were also used such as ritonavir, N-ethylnorcotinine, and milrinone. For both nicotine and cotinine, the calibration range was 0.005-35000 ng/mL, the matrix effect was 75.96% - 126.8% and the recovery was 53% - 124.5%. The two analytes were stable at room temperature for 1-10 days, at -80 °C for up to 6 months, and after 3-6 freeze-thaw cycles. Comedications did not affect nicotine and cotinine analysis.

Progress in quantification of nicotine content and form distribution in electronic cigarette liquids and aerosols

Each electronic cigarette (e-cigarette) is a battery-powered system which converts electronic cigarette liquids (e-liquids) into the inhalable phase by heating the solution when it is in use. After four generations of development, e-cigarettes tend to be more customized and user-operable. The main components in the e-liquid and the aerosol are vegetable glycerin, propylene glycol, nicotine, organic acid and some flavor ingredients. Among them, nicotine is closely associated with the irritation and physiological satisfaction caused by tobacco products, and it is the core functional substance of e-cigarettes. For this reason, the quantification of nicotine content and nicotine form distribution mainly focuses on the components of the e-liquid and the released aerosol. Up to now, various technologies and methods have been applied in the analysis and research of nicotine content and nicotine form distribution in the e-liquid and its aerosol. GC-MS is often used as the most viable tool for the analysis of volatile organic compounds and can be widely applied in the measurement of nicotine related chemicals; there are a number of quantitation strategies using LC-MS, LC-MS/MS or ¹H NMR for the analysis of e-cigarette samples. We also reviewed the four main methods for determining the distribution of nicotine forms, which are pH value derivation, solvent extraction, SPME and NMR methods. These research methods are of great significance to the upgrading and development of e-cigarette products.

Application of HPLC-QQQ-MS/MS and New RP-HPLC-DAD System Utilizing the Chaotropic Effect for Determination of Nicotine and Its Major Metabolites Cotinine, and trans-3'-Hydroxycotinine in Human Plasma Samples

The routine techniques currently applied for the determination of nicotine and its major metabolites, cotinine, and trans-3′-hydroxycotinine, in biological fluids, include spectrophotometric, immunoassays, and chromatographic techniques. The aim of this study was to develop, and compare two new chromatographic methods high-performance liquid chromatography coupled to triple quadrupole mass spectrometry (HPLC-QQQ-MS/MS), and RP-HPLC enriched with chaotropic additives, which would allow reliable confirmation of tobacco smoke exposure in toxicological and epidemiological studies. The concentrations of analytes were determined in human plasma as the sample matrix. The methods were compared in terms of the linearity, accuracy, repeatability, detection and quantification limits (LOD and LOQ), and recovery. The obtained validation parameters met the ICH requirements for both proposed procedures. However, the limits of detection (LOD) were much better for HPLC-QQQ-MS/MS (0.07 ng mL⁻¹ for trans-3′-hydroxcotinine; 0.02 ng mL⁻¹ for cotinine; 0.04 ng mL⁻¹ for nicotine) in comparison to the RP-HPLC-DAD enriched with chaotropic additives (1.47 ng mL⁻¹ for trans-3′-hydroxcotinine; 1.59 ng mL⁻¹ for cotinine; 1.50 ng mL⁻¹ for nicotine). The extraction efficiency (%) was concentration-dependent and ranged between 96.66% and 99.39% for RP-HPLC-DAD and 76.8% to 96.4% for HPLC-QQQ-MS/MS. The usefulness of the elaborated analytical methods was checked on the example of the analysis of a blood sample taken from a tobacco smoker. The nicotine, cotinine, and trans-3′-hydroxycotinine contents in the smoker’s plasma quantified by the RP-HPLC-DAD method differed from the values measured by the HPLC-QQQ-MS/MS. However, the relative errors of measurements were smaller than 10% (6.80%, 6.72%, 2.04% respectively).

Comprehensive metabolic study of nicotine in equine plasma and urine using liquid chromatography/high-resolution mass spectrometry for the identification of unique biomarkers for doping control

Nicotine is classified as a stimulant, and its use is banned in horse racing and equestrian sports by the International Federation of Horseracing Authorities and the Fédération Équestre Internationale, respectively. Because nicotine is a major alkaloid of tobacco leaves, there is a potential risk that doping control samples may be contaminated by tobacco cigarettes or smoke during sample collection. In order to differentiate the genuine doping and sample contamination with tobacco leaves, it is necessary to monitor unique metabolites as biomarkers for nicotine administration and intake. However, little is known about the metabolic fate of nicotine in horses. This is the first report of comprehensive metabolism study of nicotine in horses. Using liquid chromatography/electrospray ionization high-resolution mass spectrometry, we identified a total of 17 metabolites, including one novel horse-specific metabolite (i.e., 4-hydroxy-4-(3-pyridyl)-N-methylbutanamide), in post-administration urine samples after nasoesophageal administration of nicotine to three thoroughbred mares; eight of these compounds were confirmed based on reference standards. Among these metabolites, N-hydroxymethylnorcotinine was the major urinary metabolite in equine, but it could only be tentatively identified by mass spectral interpretation due to the lack of reference material. In addition, we developed simultaneous quantification methods for the eight target analytes in plasma and urine, and applied them to post-administration samples to establish elimination profiles of nicotine and its metabolites. The quantification results revealed that trans-3'-hydroxycotinine could be quantified for the longest period in both plasma (72 h post-administration) and urine (96 h post-administration). Therefore, this metabolite is the most appropriate monitoring target for nicotine exposure for the purpose of doping control due to its long detection times and the availability of its reference material. Further, we identified trans-3'-hydroxycotinine as a unique biomarker allowing differentiation between nicotine administration and sample contamination with tobacco leaves.

Non-linear dose-response relation between urinary levels of nicotine and its metabolites and cognitive impairment among an elderly population in China

BACKGROUND

Active smoking and exposure to environmental tobacco smoke may be related to cognitive function decline. We assessed the associations of urinary levels of nicotine and its metabolites with cognitive function.

METHODS

A total of 553 elder adults at high risk of cognitive impairment and 2212 gender- and age-matched individuals at low risk of cognitive impairment were selected at a ratio of 1: 4 from the remained individuals (n = 6771) who completed the baseline survey of the Shenzhen Ageing-Related Disorder Cohort, after excluding those with either Alzheimer's disease, Parkinson's syndrome or stroke as well as those with missing data on variables (including active and passive smoking status, Mini-Cog score). Urinary levels of nicotine and its metabolites and cognitive function for all individuals were measured by high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) and assessed using the Mini-Cog test, respectively. Associations of urinary levels of nicotine and its metabolites with cognitive function were analyzed by conditional logistic regression models.

RESULTS

Individuals in the highest tertile of urinary OHCotGluc (OR: 1.52, 95%CI: 1.19-1.93) or NNO (OR: 1.50, 95%CI: 1.16-1.93) levels as well as in the second tertile of urinary ∑Nic level (OR: 1.43, 95%CI: 1.13-1.82) were at higher risk of cognitive impairment compared with those in the corresponding lowest tertile. Restricted cubic spline models revealed the non-linear dose-response relationships between urinary levels of OHCotGluc, NNO or ∑Nic and the risk of cognitive impairment.

CONCLUSIONS

Urinary levels of OHCotGluc, NNO or ∑Nic exhibited a non-linear dose-response relationship with cognitive function in the urban elderly.

Sensitive Quantification of Nicotine in Bronchoalveolar Lavage Fluid by Acetone Precipitation Combined With Isotope-Dilution Liquid Chromatography-Tandem Mass Spectrometry

The United States experienced an outbreak of e-cigarette, or vaping, product use-associated lung injury (EVALI) that began in August 2019. Patient diagnosis and treatment sometimes involved bronchoscopy and collection of the bronchoalveolar lavage (BAL) fluid. Although this matrix has been useful for understanding some chemical exposures in the lungs, no methods existed for measuring the nicotine content. Therefore, we developed a simple and sensitive method for measuring nicotine in the BAL fluid. Nicotine was extracted from the BAL fluid using acetone precipitation in a 96-well plate format to increase the sample throughput (200 samples/day). We optimized liquid chromatography column conditions (e.g., mobile phase, column temperature) and mass spectrometry parameters to improve the signal-to-noise ratio and lower limits of detection (LOD) for measuring nicotine in the BAL fluid. The LOD for nicotine in the BAL fluid was 0.050 ng/mL at a sample volume of 40 μL of the BAL fluid. The within-day and between-day imprecision and bias were less than 10%. This method detected nicotine in 15 of 43 BAL fluids from EVALI case patients. This method is useful for understanding recent inhalational exposure to nicotine as part of characterizing EVALI or similar illnesses.

Environmental Tobacco Smoke Exposure Among Children by Urinary Biomarkers and Parent Report

OBJECTIVE

The goal of this study was to describe environmental tobacco smoke (ETS) exposure using urinary biomarkers and its correlation with parent report, among children presenting to emergency room.

METHODS

This is a case control study among children aged 3 to 12 years at a tertiary pediatric emergency department in Israel. Children with respiratory (case) or gastrointestinal (control) symptoms were recruited and their accompanying parent completed a short survey. Urine samples were obtained and analyzed for nicotine, cotinine trans-3'-hydroxycotine. Clinical data were extracted from medical records. We compared tobacco exposure using urinary biomarkers, parent report, and Pearson's product-moment correlation, including 95% confidence intervals, between cases and controls.

RESULTS

Forty-nine cases with respiratory symptoms and 96 controls with gastrointestinal symptoms were enrolled in the study. Parent-reported ETS exposure in the previous month was higher in the cases compared to control (71.4% vs 57.3%), although the difference was not statistically significant. The mean values of detectable biomarkers did not differ by between cases and controls. However, there was a correlation between urinary biomarkers and reported ETS exposure (0.278-0.460 for various biomarkers) only among cases.

CONCLUSIONS

The majority of children in this study had detectable nicotine urinary biomarkers, regardless of their symptoms. However, correlation between parental report and urinary biomarkers was only found among children with symptoms potentially related to ETS. These findings imply that parents of children without respiratory symptoms may underestimate exposure. Efforts to educate parents and caregivers on the risks associated with exposure to ETS should be intensified, regardless of illness.

Recent Developments in the Determination of Biomarkers of Tobacco Smoke Exposure in Biological Specimens: A Review

Environmental tobacco smoke exposure (ETS) and smoking have been described as the most prevalent factors in the development of certain diseases worldwide. According to the World Health Organization, more than 8 million people die every year due to exposure to tobacco, around 7 million due to direct ETS and the remaining due to exposure to second-hand smoke. Both active and second-hand exposure can be measured and controlled using specific biomarkers of tobacco and its derivatives, allowing the development of more efficient public health policies. Exposure to these compounds can be measured using different methods (involving for instance liquid- or gas-chromatographic procedures) in a wide range of biological specimens to estimate the type and degree of tobacco exposure. In recent years, a lot of research has been carried out using different extraction methods and different analytical equipment; this way, liquid-liquid extraction, solid-phase extraction or even miniaturized procedures have been used, followed by chromatographic analysis coupled mainly to mass spectrometric detection. Through this type of methodologies, second-hand smokers can be distinguished from active smokers, and this is also valid for e-cigarettes and vapers, among others, using their specific biomarkers. This review will focus on recent developments in the determination of tobacco smoke biomarkers, including nicotine and other tobacco alkaloids, specific nitrosamines, polycyclic aromatic hydrocarbons, etc. The methods for their detection will be discussed in detail, as well as the potential use of threshold values to distinguish between types of exposure.

Challenges associated with quantification of selected urinary biomarkers of exposure to tobacco products

Tobacco use, of which cigarette smoking is the most common, is a global health concern and is directly linked to over 7 million premature deaths annually. Measurement of the levels of tobacco-related biomarkers in biological matrices reflects human exposure to the chemicals in tobacco products. Nicotine, nicotine metabolites, anatabine, and anabasine are specific to tobacco and nicotine containing products. However, as nicotine and its metabolites are ubiquitous in the environment, background contamination during sample preparation can occur, making the quantification of target analytes challenging. The main purpose of the present study was to examine quality control measures needed in the determination of urinary nicotine, nicotine metabolites, anatabine, and anabasine. Urine samples (n = 75) and NIST standard reference materials SRM 3671 and SRM 3672 were analysed. A one-step extraction procedure using cold acetone was used in this study, which involved no additional clean up. The blank matrices investigated included synthetic urine prepared with HPLC-grade water, synthetic urine prepared with Milli-Q water, and bovine urine. By adopting strategies for minimizing the background levels, very low detection limits for all the target analytes ranging from 0.025 ng/mL for 3-hydroxycotinine to 0.634 ng/mL for nicotine, were achieved. Recoveries ranged between 67% and 118% with RSD values below 20%. Intra-day and inter-day precisions were in the range of 1.1-11.7% and 4.8-25.2%, respectively. The levels of all target analytes were higher in daily smokers than in non-smokers, with the largest difference observed for 3-hydroxycotinine. No difference was observed in the levels of target analytes between individuals who were former smokers, who never smoked or who were exposed to environmental tobacco smoke (ETS), except for total nicotine equivalents (TNE), which was significantly higher in non-smokers exposed to environmental tobacco smoke compared with study participants who never smoked. The results obtained from SRM 3671 and SRM 3672 could inform a potential certification of additional biomarkers of exposure to tobacco products in those standard reference materials.

A Simple and High-throughput LC-MS/MS Method for Simultaneous Measurement of Nicotine, Cotinine, 3-OH cotinine, Nornicotine, and Anabasine in Urine and its Application in the General Korean Population

Measuring nicotine metabolites is the most objective method for identifying smoke exposure. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) can measure multiple metabolites and is sensitive enough to detect low concentrations of metabolites. Therefore, we developed a simple and high-throughput method for measuring nicotine, cotinine, trans-3'-hydroxycotinine (3-OH cotinine), nornicotine, and anabasine for population-based studies using LC-MS/MS. Each 30 µl of urine sample was diluted with 90 µL of acetonitrile containing five deuterated internal standards. Chromatographic separation used a C18 column and LC-MS/MS analysis was performed with a multiple reaction monitoring mode. The chromatographic run time for each sample was 6.5 min. The method was validated by evaluating selectivity, interference, limit of detection, lower limit of quantification, precision, accuracy, linearity, extraction recovery, matrix effect, and carry-over according to guidelines. Our methods required a short preparation time (about 20 minutes) while simultaneously measuring five markers for smoking status. No endogenous or exogenous interference was found. Our method showed excellent precision and accuracy: within-run CV 2.9-9.4%, between-run CV 4.8-8.7%, and bias -10.1 to 5.3%. Linear dynamic ranges were 1-10,000 ng/mL for nicotine, nornicotine, and anabasine; 2-5,000 ng/mL for cotinine; and 5-15,000 ng/mL for 3-OH cotinine. Extraction recovery was consistent (87-109%) across concentrations. No significant matrix effect or carry-over was observed. The validated method was applied to 849 urine samples. In samples from the 125 current smokers, nicotine, cotinine, 3-OH cotinine, nornicotine, and anabasine were detected in 97.6%, 99.2%, 98.4%, 96.8%, and 87.2%, respectively. No markers were detected in 93.9% of 609 non-smokers. The overlapping detection of multiple markers made it possible to identify smoking status even in current smokers with low concentration of cotinine. Our LC-MS/MS method using a simple sample preparation technique is sensitive and effective for screening of smoking status in the general population.

Isotope dilution-LC-MS/MS method for quantification of the urinary cotinine-to-creatinine ratio

Background

Appropriate monitoring of tobacco smoking is extremely important in several areas of medicine, e.g. management of chronic obstructive pulmonary disease (COPD), epidemiological surveys, and allocation of heart or lung transplants. The major metabolite of nicotine is cotinine that is increasingly used as a laboratory parameter for assessing tobacco smoke exposure.

Methods

Creatinine and cotinine were analyzed simultaneously in urine by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) in one run within 3 min using a biphenyl column. For quantification, the respective stable-isotope-labeled standards were used.

Results

Detuning and measuring a natural isotope of creatinine as precursor and product ion allowed a simultaneous quantification of creatinine and cotinine. The method revealed robust validation results. For both analytes, inaccuracy and imprecision of the quality control and external quality assessment (EQA) samples were ≤-11.1%.

Conclusions

One essential novelty of the method presented here is the simultaneous quantification of creatinine and cotinine covered by one analytical method. Despite the very different natural concentrations of creatinine and cotinine, this allows the immediate reporting of the cotinine-to-creatinine ratio without the need for a separate creatinine analysis.

Pregnancy-Induced Increases in the Nicotine Metabolite Ratio: Examining Changes During Antepartum and Postpartum

INTRODUCTION

Pregnancy-induced increases in nicotine metabolism may contribute to difficulties in quitting smoking during pregnancy. However, the time course of changes in nicotine metabolism during early and late pregnancy is unclear. This study investigated how pregnancy alters the nicotine metabolite ratio (NMR), a common biomarker of nicotine metabolism among nonpregnant smokers.

METHODS

Urinary NMR (trans-3'-hydroxycotinine [3HC]/cotinine [COT]) was assessed using total (free + glucuronide) and free compounds among women (N = 47) from a randomized controlled trial for smoking cessation who self-reported smoking and provided a urine sample during early pregnancy (M ± SD = 12.5 ± 4.5 weeks' gestation), late pregnancy (28.9 ± 2.0 weeks' gestation), and 6 months postpartum (24.7 ± 1.2 weeks since childbirth). Urine samples were analyzed using liquid chromatography-tandem mass spectrometry and NMR were calculated as Total 3HC/Free COT, Free 3HC/Free COT, and Total 3HC/Total COT.

RESULTS

NMR was significantly higher during early and late pregnancy compared to postpartum and significantly increased from early to late pregnancy as measured by Total 3HC/Free COT (0.76, 0.89, 0.60; all p's < .05) and Free 3HC/Free COT (0.68, 0.80, 0.51; all p's < .05). Total 3HC/Total COT did not vary over time (p = .81).

CONCLUSIONS

Total 3HC/Free COT and Free 3HC/Free COT increased in the first trimester and continued to increase throughout pregnancy, suggesting a considerable increase in nicotine metabolism over gestation. Future analyses are needed to interpret the changes in NMR in the context of nicotine pharmacokinetics, as well as its impact on changes in smoking behavior and cessation outcomes.

IMPLICATIONS

We observed that the NMR was significantly higher as early as 12 weeks' gestation and increased further as a function of gestational age. Among nonpregnant smokers, elevated NMR is associated with smoking phenotypes such as smoking more cigarettes per day and poorer response to nicotine patch; therefore, pregnancy-induced increases in the NMR may contribute to smoking during the first trimester of pregnancy and reducing or quitting smoking may become more challenging as the rate of nicotine metabolism accelerates over the course of pregnancy.

In vivo quantification and pharmacokinetic studies of cotinine in mice after smoke exposure by LC-MS/MS

A sensitive analytical method was developed and validated for the quantification of cotinine in mouse plasma after exposure to smoke of 0.5, 1.0, and 1.5 commercially available cigarettes, using liquid chromatography tandem mass spectrometry. The method was validated over a linear concentration range of 0.075-20.0 ng/mL with the R² value being higher than 0.99. Both the precision (coefficient of variation; %) and accuracy (relative error; %) were within acceptable criteria of <15%. The lower limit of quantification (LLOQ) for cotinine was 0.075 ng/mL with sufficient specificity, accuracy, and precision. Following exposure to 0.5, 1.0, and 1.5 cigarette smoke, it was observed that the AUC and the C_max increased linearly as the doses increased. The pharmacokinetics of cotinine was found linear for the range of 0.5-1.5 commercial cigarette smoke. The quantification of the concentration of cotinine in mouse plasma after smoke exposure will facilitate future behavioral and toxicological experiments in animals and may prove useful in predicting cotinine levels in humans during smoking.

Nicotine intoxication by e-cigarette liquids: a study of case reports and pathophysiology

Background: Electronic cigarettes (e-cigarettes), the smokeless alternative to conventional tobacco cigarettes, have become increasingly popular. E-cigarettes vaporise e-liquid, a solution of highly concentrated nicotine, propylene glycol (PG) and vegetable glycerine (VG). With the popularity of e-cigarettes, e-liquid refills have become easily accessible and several cases of intoxication due to the ingestion of e-liquid have been reported. We provide an overview of these cases, their pathophysiology and patients' characteristics.Methods: We carried out a retrospective evaluation of the scientific literature reporting on cases of liquid nicotine intoxication, using the following inclusion criteria: (1) the article is or contains a case report, (2) describes an intoxication with e-liquid, (3) the substance contains nicotine, and (4) intake is oral, intravenous or subcutaneous.Results: We found 26 case reports describing a total of 31 patients who suffered from e-liquid intoxication. All intoxications up to the age of six were reported as unintentional, whereas nearly all cases from ages 13 to 53 were due to suicide attempts. The three most prevalent symptoms of e-liquid intoxication were tachycardia, altered mental status and vomiting. Eleven cases resulted in the death of the patient. In the survivors, the highest plasma concentration of nicotine was 800 µg L^-1, while the lowest concentration in the non-survivors was 1600 µg L^-1.Conclusions: There is a mismatch between the generally accepted lethal oral nicotine dose of 60 mg, resulting in approximately 180 µg L^-1 plasma concentration, and the 4.4- to 8.9-fold higher lethal plasma concentrations we found in cases of e-liquid intoxication. In these severe intoxications, plasma cotinine concentration does not act as a more reliable indicator of nicotine intoxication than nicotine itself. The ages of the patients display a bimodal distribution. In patients above the age of 10, intoxication results mainly from suicide attempts rather than accidental ingestion. The role of PG and VG in e-liquid intoxications is remarkably unclear. However, the similarity across nicotine and PG toxicity symptoms leads us to believe a cumulative effect cannot be excluded.

Evidence for respiratory viruses interactions in asymptomatic preschool-aged children

Aim

To prospectively evaluate interferences between viruses of the upper respiratory tract in asymptomatic preschool children.

Methods

Nasal-pharyngeal swabs from 233 preschool aged children were prospectively collected over four consecutive time periods, during one school year. The samples were tested using a RT-PCR DNA/RNA microarray system for nine respiratory viruses.

Results

Respiratory syncytial virus (RSV) was a predictor of the presence of influenza virus (INFL) (OR: 9.12, CI: 1.52–54.75, p = 0.016), and similarly, INFL predicted the presence of RSV (OR: 4.01, CI: 1.14–14.16, p = 0.030). Also, rhinovirus (RV) was a predictor of adenovirus (ADV) presence (OR: 3.66, CI: 1.10–12.14, p = 0.034), and similarly, ADV predicted the presence of RV (OR: 4.05, CI: 1.02–16.05, p = 0.046). No other significant associations between viruses were observed.

Conclusion

Our results indicate that respiratory viruses found in carrier stage in asymptomatic children may interact with other viruses and even facilitate their settling in the upper respiratory tract. The pathophysiological role of these interactions is not yet clear.

Counselling for smoking cessation during pregnancy reduces tobacco-specific nitrosamine (NNAL) concentrations: A randomized controlled trial

INTRODUCTION

Smoking cessation during pregnancy is beneficial to both the mother and child. Our objective was to assess if an intensive smoking cessation intervention for pregnant women increases: a) rates of smoking cessation, and b) reduces exposure to tobacco-specific carcinogens during pregnancy.

METHODS

A two-group single-blinded parallel randomized controlled trial (RCT) was conducted involving 84 pregnant smokers in either a high intensity (n=42) or minimal contact control group (n=42). Women assigned to the high intensity smoking cessation intervention group received a single 30-minute behavioural counselling session and a tailored self-help booklet. The primary outcome measures were: 7-day point prevalence abstinence measured by selfreport and urine cotinine levels, and maternal tobacco specific carcinogens nitrosamine (NNAL) urine concentrations assessed at 32 weeks of gestation.

RESULTS

A significantly greater percentage of pregnant smokers quit smoking in the high intensity group compared to the low intensity control group (45.2% vs 21.4%; p=0.001). A significant decrease in urine cotinine concentrations was documented in the experimental group (-140.74 ± 361.70 ng/mL; p=0.004), with no significant decrease documented in the control group. A significant decrease in NNAL levels was also documented in the experimental group (158.17 ± 145.03 pg/mL before, 86.43 ± 112.54 pg/mL after; p=0.032) with no significant changes in the control group.

CONCLUSIONS

The high intensity intervention tested resulted in significantly greater cessation rates. Intensive smoking cessation interventions can be effective in reducing fetal exposure to NNAL. This is the first trial to report on NNAL tobacco-specific carcinogen concentrations before and after an intervention for smoking cessation during pregnancy.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01210118.

ABBREVIATIONS

5Αs: ask, advise, asses, assist, arrange; GHQ: general health questionnaire; ANOVA: analysis of variance; RCT: randomized control trials; NNAL: 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol.

Simultaneous determination of tobacco minor alkaloids and tobacco-specific nitrosamines in mainstream smoke by dispersive solid-phase extraction coupled with ultra-performance liquid chromatography/tandem orbitrap mass spectrometry

RATIONALE

The minor alkaloids in tobacco play an important role in the chemical composition of cigarette smoke, and they are precursors of tobacco-specific nitrosamines (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), N-nitrosonornicotine (NNN), N-nitrosoanabasine (NAB) and N-nitrosoanatabine (NAT)). NNN and NNK are classified as group 1 carcinogens. A method quantitating both tobacco minor alkaloids and tobacco-specific nitrosamines in mainstream smoke has not been reported.

METHODS

Tobacco minor alkaloids and tobacco-specific nitrosamines in cigarette mainstream smoke were extracted by sonication. The extract was cleaned up by dispersive solid-phase extraction, and separation was achieved via ultra-performance liquid chromatography/tandem orbitrap mass spectrometry.

RESULTS

The method was validated by analysis of six replicate samples spiked with three levels of the analyses. The mean recoveries for the six replicates were from 84.7% to 118% with less than 15% relative standard deviation except myosmine at the low spiked level and the calculated detection limits were 0.066 to 13.2 ng/cig, respectively. The mean concentrations of nicotyrine, anabasine, nornicotine, anatabine, myosmine, 2,3-bipyridine, cotinine, nicotelline, N-formylnornicotine, NNK, NNN, NAB and NAT in 30 different brands of commercial cigarette smoke under the ISO smoking regimen were 2.50 μg/cig, 2.34 μg/cig, 3.21 μg/cig, 5.78 μg/cig, 2.83 μg/cig, 1.05 μg/cig, 1.55 μg/cig, 0.55 μg/cig, 2.48 μg/cig, 6.06 ng/cig, 3.62 ng/cig, 0.40 ng/cig and 6.15 ng/cig, respectively.

CONCLUSIONS

The proposed method was suitable for analysis of tobacco minor alkaloids and tobacco-specific nitrosamines in cigarette mainstream smoke.

A Comparison of Direct and Indirect Analytical Approaches to Measuring Total Nicotine Equivalents in Urine

Background: Total nicotine equivalents (TNE), the sum of nicotine and metabolites in urine, is a valuable tool for evaluating nicotine exposure. Most methods for measuring TNE involve two-step enzymatic hydrolysis for indirect quantification of glucuronide metabolites. Here, we describe a rapid, low-cost direct LC/MS assay.Methods: In 139 smokers' urine samples, Bland-Altman, correlation, and regression analyses were used to investigate differences in quantification of nicotine and metabolites, TNE, and nicotine metabolite ratio (NMR) between direct and indirect LC/MS methods. DNA from a subset (n = 97 smokers) was genotyped for UGT2B10*2 and UGT2B17*2, and the known impact of these variants was evaluated using urinary ratios determined by the direct versus indirect method.Results: The direct method showed high accuracy (0%-9% bias) and precision (3%-14% coefficient of variation) with similar distribution of nicotine metabolites to literary estimates and good agreement between the direct and indirect methods for nicotine, cotinine, and 3-hydroxycotinine (ratios 0.99-1.07), but less agreement for their respective glucuronides (ratios 1.16-4.17). The direct method identified urinary 3HC+3HC-GLUC/COT as having the highest concordance with plasma NMR and provided substantially better estimations of the established genetic impact of glucuronidation variants compared with the indirect method.Conclusions: Direct quantification of nicotine and metabolites is less time-consuming and less costly, and provides accurate estimates of nicotine intake, metabolism rate, and the impact of genetic variation in smokers.Impact: Lower cost and maintenance combined with high accuracy and reproducibility make the direct method ideal for smoking biomarker, NMR, and pharmacogenomics studies. Cancer Epidemiol Biomarkers Prev; 27(8); 882-91. ©2018 AACR.

Comparison of the Conventional and Electroenhanced Direct-Immersion Solid-Phase Microextraction for Sampling of Nicotine in Biological Fluids of the Human Body

A stainless steel fiber was made porous and adhesive by platinization and then coated by nanostructured polypyrrole (PPy), using an appropriate electrophoretic deposition (EPD) method. The morphological surface structure and functional groups of the PPy-coated fiber were studied using SEM (Scanning electron microscope) instrument. The prepared fiber was used for comparison of direct immersion (DI) and electroenhanced direct immersion solid-phase microextraction (EE-DI-SPME) of nicotine in human plasma and urine samples followed by gas chromatography flame ionization detector (GC-FID) determination. The effects of the influential experimental parameters on the efficiency of the DI-SPME and EE-DI-SPME methods, including the pH and ionic strength of the sample solution, applied Direct current (DC) voltage, extraction temperature and time and stirring rate, were optimized. Under the optimal conditions, the calibration curves for the DI-SPME-GC-FID and EE-DI-SPME-GC-FID methods were linear over the ranges of 0.1⁻10.0 μg mL^-1 and 0.001⁻10.0 μg mL^-1, respectively. The relative standard deviations (RSDs, n = 6) were found to be 6.1% and 4.6% for the DI and EE strategies, respectively. The LODs (limit of detection) of the DI-SPME-GC-FID and EE-DI-SPME-GC-FID methods were found to be 10 and 0.3 ng mL^-1, respectively. The relative recovery values (for the analysis of 1 µg mL^-1 nicotine) were found to be 91⁻110% for EE-DI-SPME and 75⁻105% for DI-SPME. The enrichment factors for DI-SPME and EE-DI-SPME sampling were obtained as 38,734 and 50,597, respectively. The results indicated that EE-SPME was more efficient for quantitation of nicotine in biological fluids. The developed procedure was successfully carried out for the extraction and measurement of nicotine in real plasma and urine samples.

Longitudinal Influence of Pregnancy on Nicotine Metabolic Pathways

Nicotine metabolism increases in pregnancy, which may contribute to the difficulties that pregnant women have in quitting smoking. We aimed to determine the extent and timing of changes in nicotine metabolic pathways, including C-oxidation, N-glucuronidation, and the pregnancy-induced influences on the activity of enzymes mediating these pathways (CYP2A6 and UGT2B10, respectively). Current smoking pregnant women (n = 47) provided a urine sample during early pregnancy (12.5 weeks), late pregnancy (28.9 weeks), and 6 months postpartum. Concentrations of urinary nicotine and metabolites were analyzed using liquid chromatography tandem mass spectrometry and compared using general linear repeated measures analyses. Nicotine C-oxidation was 1.07-fold (P = 0.12) and 1.11-fold (P < 0.001) higher at early and late pregnancy, respectively, compared with postpartum. Nicotine N-glucuronidation was 1.33-fold (P = 0.06) and 1.67-fold (P = 0.003) higher at early and late pregnancy, respectively, compared with postpartum. The CYP2A6 phenotype ratio (total 3'-hydroxycotinine/cotinine) was significantly higher at early and late pregnancy compared with postpartum (all P < 0.05) and correlated with nicotine C-oxidation (all P < 0.001), suggesting CYP2A6 activity is induced during pregnancy. The UGT2B10 phenotype ratio (nicotine glucuronide/nicotine) was higher at early and late pregnancy compared with postpartum (P = 0.07 and P < 0.05, respectively) and correlated with a second UGT2B10 phenotype ratio (cotinine glucuronide/cotinine) (all P < 0.001), suggesting UGT2B10 activity is induced during pregnancy. In conclusion, pregnancy-induced increases in nicotine metabolism start by 12 weeks gestation and continue as pregnancy progresses most likely due to induction of CYP2A6 and UGT2B10, resulting in potential reductions in the effectiveness of nicotine replacement therapies and an increase in metabolism of other CYP2A6 and UGT2B10 substrates during pregnancy.

Maternal marijuana use, adverse pregnancy outcomes, and neonatal morbidity

BACKGROUND

The Eunice Kennedy Shriver National Institute of Child Health and Human Development Stillbirth Collaborative Research Network previously demonstrated an association between stillbirth and maternal marijuana use as defined by the presence of 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid in the umbilical cord homogenate. However, the relationship between marijuana use and perinatal complications in live births is uncertain.

OBJECTIVE

Our aim was to examine if maternal marijuana use is associated with increased odds of adverse pregnancy outcomes and neonatal morbidity among live-born controls in the Stillbirth Collaborative Research Network cohort.

STUDY DESIGN

We conducted a secondary analysis of singleton, live-born controls in the Stillbirth Collaborative Research Network data set. Marijuana use was measured by self-report and/or the presence of 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid in umbilical cord homogenate. Tobacco use was measured by self-report and/or presence of any cotinine in maternal serum. Adverse pregnancy outcome was a composite of small for gestational age, spontaneous preterm birth resulting from preterm labor with or without intact membranes, and hypertensive disorders of pregnancy. Neonatal morbidity included neonatal intensive care unit admission and composite neonatal morbidity (pulmonary morbidity, necrotizing enterocolitis, seizures, retinopathy of prematurity, infection morbidity, anemia requiring blood transfusion, neonatal surgery, hyperbilirubinemia, neurological morbidity, or death prior to hospital discharge). Effect of maternal marijuana use on the probability of an adverse outcome was estimated using weighted methodology to account for oversampling in the original study. 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid cord homogenate analysis was performed in the subset of women for whom biospecimens were available. Comparisons using logistic modeling, χ², and t tests were weighted to account for oversampling of preterm births and non-Hispanic blacks. Results are reported as weighted percent and unweighted frequencies.

RESULTS

Maternal marijuana use was identified in 2.7% (unweighted frequency 48/1610) of live births. Use was self-reported by 1.6% (34/1610) and detected by 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid in cord homogenate for 1.9% (17/897), n = 3 overlapping. Rate of tobacco use was 12.9% (217/1610), with 10.7% (167/1607) by self-report and 9.5% (141/1313) by serum cotinine. The composite adverse pregnancy outcome was not significantly increased in women with marijuana use compared to nonusers (31.2% vs 21.2%; P = .14). After adjustment for tobacco, clinical, and socioeconomic factors, marijuana use was not associated with the composite adverse pregnancy outcome (adjusted odds ratio, 1.29; 95% confidence interval, 0.56-2.96). Similarly, among women with umbilical cord homogenate and serum cotinine data (n = 765), marijuana use was not associated with adverse pregnancy outcomes (adjusted odds ratio, 1.02; 95% confidence interval, 0.18-5.66). Neonatal intensive care unit admission rates were not statistically different between groups (16.9% users vs 9.5% nonusers, P = .12). Composite neonatal morbidity or death was more frequent among neonates of mothers with marijuana use compared to nonusers (14.1% vs 4.5%; P = .002). In univariate comparisons, the components of the composite outcome that were more frequent in neonates of marijuana users were infection morbidity (9.8% vs 2.4%; P < .001) and neurologic morbidity (1.4% vs 0.3%; P = .002). After adjustment for tobacco, race, and other illicit drug use, marijuana use was still associated with composite neonatal morbidity or death (adjusted odds ratio, 3.11; 95% confidence interval, 1.40-6.91).

CONCLUSION

Maternal marijuana use was not associated with a composite of small for gestational age, spontaneous preterm birth, or hypertensive disorders of pregnancy. However, it was associated with an increased risk of neonatal morbidity.

Development of a Cigarette Tobacco Filler Standard Reference Material

A new tobacco filler Standard Reference Material (SRM) has been issued by the National Institute of Standards and Technology (NIST) in September 2016 with certified and reference mass fraction values for nicotine, N-nitrosonornicotine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, and volatiles. The constituents have been determined by multiple analytical methods with measurements at NIST and at the Centers for Disease Control and Prevention, and with confirmatory measurements by commercial laboratories. This effort highlights the development of the first SRM for reduced nicotine and reduced tobacco-specific nitrosamines with certified values for composition.

Population pharmacokinetic model of transdermal nicotine delivered from a matrix-type patch

AIMS

Nicotine addiction is an issue faced by millions of individuals worldwide. As a result, nicotine replacement therapies, such as transdermal nicotine patches, have become widely distributed and used. While the pharmacokinetics of transdermal nicotine have been extensively described using noncompartmental methods, there are few data available describing the between-subject variability in transdermal nicotine pharmacokinetics. The aim of this investigation was to use population pharmacokinetic techniques to describe this variability, particularly as it pertains to the absorption of nicotine from the transdermal patch.

METHODS

A population pharmacokinetic parent-metabolite model was developed using plasma concentrations from 25 participants treated with transdermal nicotine. Covariates tested in this model included: body weight, body mass index, body surface area (calculated using the Mosteller equation) and sex.

RESULTS

Nicotine pharmacokinetics were best described with a one-compartment model with absorption based on a Weibull distribution and first-order elimination and a single compartment for the major metabolite, cotinine. Body weight was a significant covariate on apparent volume of distribution of nicotine (exponential scaling factor 1.42). After the inclusion of body weight in the model, no other covariates were significant.

CONCLUSIONS

This is the first population pharmacokinetic model to describe the absorption and disposition of transdermal nicotine and its metabolism to cotinine and the pharmacokinetic variability between individuals who were administered the patch.

Detoxification and elimination of nicotine by nectar-feeding birds

Many dilute nectars consumed by bird pollinators contain secondary metabolites, potentially toxic chemicals produced by plants as defences against herbivores. Consequently, nectar-feeding birds are challenged not only by frequent water excess, but also by the toxin content of their diet. High water turnover, however, could be advantageous to nectar consumers by enabling them to excrete secondary metabolites or their transformation products more easily. We investigated how the alkaloid nicotine, naturally present in nectar of Nicotiana species, influences osmoregulation in white-bellied sunbirds Cinnyris talatala and Cape white-eyes Zosterops virens. We also examined the metabolic fate of nicotine in these two species to shed more light on the post-ingestive mechanisms that allow nectar-feeding birds to tolerate nectar nicotine. A high concentration of nicotine (50 µM) decreased cloacal fluid output and increased its osmolality in both species, due to reduced food intake that led to dehydration. White-eyes excreted a higher proportion of the ingested nicotine-containing diet than sunbirds. However, sugar concentration did not affect nicotine detoxification and elimination. Both species metabolised nicotine, excreting very little unchanged nicotine. Cape white-eyes mainly metabolised nicotine through the cotinine metabolic pathway, with norcotinine being the most abundant metabolite in the excreta, while white-bellied sunbirds excreted mainly nornicotine. Both species also utilized phase II conjugation reactions to detoxify nicotine, with Cape white-eyes depending more on the mercapturic acid pathway to detoxify nicotine than white-bellied sunbirds. We found that sunbirds and white-eyes, despite having a similar nicotine tolerance, responded differently and used different nicotine-derived metabolites to excrete nicotine.

Direct screening of tobacco indicators in urine and saliva by Atmospheric Pressure Solid Analysis Probe coupled to quadrupole-time of flight mass spectrometry (ASAP-MS-Q-TOF-)

A new screening method has been explored for direct analysis of tobacco smoke biomarkers in biological matrices (i.e., saliva and urine). Single run analysis using Atmospheric pressure Solid Analysis Probe (ASAP) and high resolution mass spectrometry with quadrupole and time of flight detector has been applied directly to some biological samples (i.e., urine and saliva), providing a fast, efficient and sensitive method of identification. The method has been applied to saliva and urine samples from heavy tobacco smokers for exposure studies. Nicotine itself, nicotine metabolites (i.e., cotinine, trans-3'-hydroxycotinine, nicotine-N-glucuronide) and other related tobacco smoke toxic compounds (i.e., NNK 4-[methyl(nitroso)amino]-1-(3-pyridinyl)-1-butanone, anatabine) were found in the analyzed samples. The identification of compounds was confirmed by ultrahigh performance liquid chromatography with MS-triple quadrupole detector after sample treatment. Different temporal trends and biomarkers behavior have been found in time series related samples. Both methods are compared for screening of these biological matrices.

Determination of Nicotine, Cotinine and Trans-3'-Hydroxycotinine using LC/MS/MS in Forensic Samples of a Nicotine Fatal Case by Oral Ingestion of e-cigarette Liquid

Nicotine is a potent neurotoxin alkaloid and is used in e-cigarette liquid. The LC/MS/MS method was linear over 0.01-1.0 mg/L (r² = 0.992-0.995). Limit of detection and limit of quantitation were 0.001 mg/L (S/N = 3) and 0.003 (S/N = 10). The inaccuracy and imprecision were <13.2%. The recoveries were >99.3%. A 39-year-old dentist was found dead lying on the floor under the couch in his dental clinic. The concentration of nicotine, cotinine, and trans-3'-hydroxycotinine (heart blood/peripheral blood) was analyzed as follows: 87.2/85.2 mg/L (ratio 1.0), 1.4/1.1 mg/L (ratio 1.3), and 0.012/0.0089 mg/L (ratio 1.3), respectively. The concentration of nicotine was determined to be 6734.8 mg/kg in gastric contents and 7262.0 mg/L in remaining e-liquid. Only, high concentration of nicotine was detected in the gastric contents as well as the two pieces of evidence collected from the death scene. This fatal case resulted from oral ingestion of e-cigarette liquid. It is estimated that at least 714 mg of nicotine was orally ingested.

Quantitation of the Minor Tobacco Alkaloids Nornicotine, Anatabine, and Anabasine in Smokers' Urine by High Throughput Liquid Chromatography-Mass Spectrometry

Nicotine is the most abundant alkaloid in tobacco accounting for 95% of the alkaloid content. There are also several minor tobacco alkaloids; among these are nornicotine, anatabine, and anabasine. We developed and applied a 96 well plate-based capillary LC-tandem mass spectrometry method for the analysis of nornicotine, anatabine, and anabasine in urine. The method was validated with regard to accuracy and precision. Anabasine was quantifiable to low levels with a limit of quantitation (LOQ) of 0.2 ng/mL even when nicotine, which is isobaric, is present at concentrations >2500-fold higher than anabasine. This attribute of the method is important since anatabine and anabasine in urine have been proposed as biomarkers of tobacco use for individuals using nicotine replacement therapies. In the present study, we analyzed the three minor tobacco alkaloids in urine from 827 smokers with a wide range of tobacco exposures. Nornicotine (LOQ 0.6 ng/mL) was detected in all samples, and anatabine (LOQ, 0.15 ng/mL) and anabasine were detected in 97.7% of the samples. The median urinary concentrations of nornicotine, anatabine, and anabasine were 98.9, 4.02, and 5.53 ng/mL. Total nicotine equivalents (TNE) were well correlated with anatabine (r(2) = 0.714) and anabasine (r(2) = 0.760). TNE was most highly correlated with nornicotine, which is also a metabolite of nicotine. Urine samples from a subset of subjects (n = 110) were analyzed for the presence of glucuronide conjugates by quantifying any increase in anatabine and anabasine concentrations after β-glucuronidase treatment. The median ratio of the glucuronidated to free anatabine was 0.74 (range, 0.1 to 10.9), and the median ratio of glucuronidated to free anabasine was 0.3 (range, 0.1 to 2.9). To our knowledge, this is the largest population of smokers for whom the urinary concentrations of these three tobacco alkaloids has been reported.

Recent advances in MS methods for nicotine and metabolite analysis in human matrices: clinical perspectives

Tobacco smoking is a major global health issue and represents the leading cause of preventable death in the developed countries. Nicotine is a major alkaloid found in tobacco products and its detection with its metabolites in human matrices is generally used for assessing tobacco consumption and second hand exposure. Several analytical techniques have been developed for the detection of nicotine and its metabolites, and MS coupled with chromatography is considered the standard reference method because of its superior sensitivity and specificity. In this work, we reviewed nicotine metabolism, clinical MS and the latest (2009-2014) development of MS-based techniques for measurement of nicotine and metabolites in human matrices. Appropriate biomarker and matrix selection are also critically discussed.

The chemical components of electronic cigarette cartridges and refill fluids: review of analytical methods

INTRODUCTION

To date, several concerns have been raised on the purity of ingredients employed in the manufacturing processes of refill fluids and cartridges, the device functionality, and the quality control of electronic cigarettes. This article reviews analytical methods so far described for the analysis of liquids to detect their chemical components and to investigate the presence of toxicants and carcinogens that can potentially occur as impurities of ingredients or as a consequence of their degradation.

RESULTS AND DISCUSSION

Based on the scientific literature, high-performance liquid chromatography with diode-array detection (HPLC/DAD) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) are most appropriate for determining nicotine and related compounds in fluids and cartridges, whereas LC-MS/MS has been successfully used to determine nitrosamines. Content analyses of glycols have been performed using gas chromatography equipped with flame ionization detector or gas chromatography/mass spectrometry (GC/MS), whereas carbonyl and other volatile organic compounds determinations have been performed by HPLC/DAD and GC/MS, respectively. Content analyses of heavy metals have been performed by inductively coupled plasma optical emission spectroscopy or inductively coupled plasma mass spectrometry. Since new potentially toxic substances may be created during heating, it is also necessary to investigate the chemical composition of generated aerosol. In this case, similar methods applied for tobacco smoke can be adopted.

CONCLUSIONS

A broad range of analytical techniques are available for the detection of constituents and toxicants in e-liquids and cartridges. Analyses of liquids have been performed with pharmacopeia procedures and methods (International Organization for Standardization, Environmental Protection Agency, and American Public Health Association) developed for other matrices but applicable to e-liquids. Because new potentially harmful substances may be produced during heating process, analyses of aerosol are needed to correlate its composition to the chemical components of liquids.