Volume 27 (2017): Issue 8 (December 2017)

Based on the knowledge gained from published studies, a new analytical method has been developed for the quantification of mercury (Hg) in the gas-vapor phase of mainstream cigarette smoke and in heated tobacco aerosol generated by a tobacco heating system (THS) using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). From a preliminary test, the mercury concentration in the particulate matter of mainstream smoke from Kentucky reference cigarettes 3R4F generated under the International Organization for Standardization (ISO) smoking regimen was compared with the mercury concentration in the gasvapor phase to assure that mercury is only measurable in the gas-vapor phase, as reported in an earlier published study. The particulate matter was collected using an electrostatic precipitation trap and was analyzed by ICP-MS after a mineralization step. The gas-vapor phase was trapped in the same smoking run as for the particulate matter using two impingers containing a nitric acid-hydrochloric acid-gold solution. The impingers were connected in series behind the electrostatic precipitation trap and the combined impinger solution was analyzed by ICP-MS after sample dilution without further sample treatment. The addition of gold has shown to be efficient for maintaining mercury in an ionized form in the impinger solution and to minimize the mercury memory effect in the sample introduction system of the ICP-MS. Only mercury in the gas-vapor phase could be quantified whereas the signal for mercury in the particulate matter was found close to those of blank solutions and was not measurable, as already mentioned in an earlier study. Following this preliminary test, the electrostatic precipitation trap was replaced by a Cambridge filter pad for the separation of the gas-vapor phase from the particulate matter where only mercury in the gas-vapor phase was quantified.

The method for the quantification of mercury in the gas-vapor phase of aerosols obtained under Health Canada (HC) and ISO smoking regimens was validated according to International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) and Association of Official Analytical Chemists (AOAC) guidelines. Accuracy profiles were evaluated as described in Association Française de Normalisation (AFNOR). The regression curve was shown to be linear within the evaluated concentration range from 25 pg/mL to 1000 pg/mL with a weighting factor 1/x. The coefficients of variation for repeatability (r) were 3.6% for 3R4F and 4.8% for THS under HC smoking regimen and 3.6% for 3R4F and 4.6% for THS under ISO smoking regimen. The coefficients of variation for intermediate precision (IP) were 7.7% for 3R4F and 7.7% for THS under HC smoking regimen and 4.7% for 3R4F and 4.6% for THS under ISO smoking regimen. The nominal mercury concentrations for 3R4F obtained during the validation under both HC and ISO smoking regimens were found to be in line with results reported in a previously published CORESTA study.

Polyphenols are chemicals found in tobacco that are affected by the method used to cure the leaf and, as a result, can be useful in the characterization of tobacco products. The purpose of this work was to develop an analytical method to investigate the levels of six polyphenols found in tobacco leaves and tobacco products: 3-O-caffeoylquinic acid (chlorogenic acid), 4-O-caffeoylquinic acid (cryptochlorogenic acid), 5-O-caffeoylquinic acid (neochlorogenic acid), kaempferol 3-O-rutinoside (nicotiflorin), quercetin 3-O-rutinoside (rutin), and 6-methoxy-7-hydroxycoumarin (scopoletin). Extraction conditions for sample preparation using PLE and instrument conditions for analysis by UPLC-MS/MS were optimized and validated. Results from the analysis of 30 cured tobacco leaves are presented and discussed in the context of each curing method represented. Results from the analysis of various tobacco products are also presented and trends observed across product types are discussed in the context of the applicability of the validated method. Total polyphenol levels for flue-cured, Oriental, and air-cured leaves were determined to be in the ranges of 18–41 mg/g, 5–27 mg/g, and 0.5–3 mg/g respectively. Similarly, cigarette polyphenol levels were found in the range of 4–16 mg/g and cigar polyphenol levels were less than 1.5 mg/g. The trends observed in the results for the tobacco leaf samples are consistent with expectations regarding the fate of polyphenols under the conditions commonly used in curing procedures. The results for the tobacco products demonstrate that the validated method can be used to study polyphenol content in cigarettes and a variety of cigar types including pipe tobacco cigars.

This study focused on the variation in the yields of constituents in smoke from commercial cigarette brands available on the Japanese market. Nineteen commercial cigarette brands were sampled five times every two months from 2009 to 2010. The target constituents were benzo[a]-pyrene, 1,3-butadiene, benzene, formaldehyde, acetaldehyde, acrolein, N-nitrosonornicotine (NNN), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), carbon monoxide, “tar”, and nicotine. The results of this study showed that the coefficient of variation (CV) values varied greatly by brands, constituents, and smoking regimes. The yields of NNN and NNK in the smoke were strongly correlated to their yields in the tobacco filler blend for most brands. The yields of benzo[a]pyrene under the International Organization for Standardization (ISO) and the Health Canada Intense (HCI) smoking regimes and 1,3-butadiene under the HCI smoking regime were found to be influenced by the measurement. It was shown that factors for variation were highly varied among constituents. The grand mean of CV values for NNN and formaldehyde associated with cigarette manufacturing over ten months and measurement at the JT laboratory under the HCI smoking regimes were 17.1% and 6.6% respectively. The grand mean of CV values for NNN and formaldehyde associated with both cigarette manufacturing over ten months and measurement at different laboratories under the HCI smoking regimes were 23.7% and 22.9% respectively. This is due to the fact that formaldehyde showed the highest CV values for reproducibility among the constituents. Thus, in order to set realistic and robust confidence intervals, it is very important to take into account the variations associated with cigarette manufacturing and measurement within and between laboratories.

The smoking questionnaire (SQ), a multidimensional questionnaire covering the major dimensions of cigarette smoking, was developed to address the heterogeneity in the assessment of smoking exposure. It consists of eight questions and can be completed within a few minutes. Test-retest reliability of the SQ and concurrent validity with the Behavior Risk Factor Surveillance System (BRFSS) 2011 questionnaire were examined in a clinical study conducted in adult US current menthol cigarette smokers. The SQ and the BRFSS were self-administrated twice before and after randomization with a 6-day interval. The inter-temporal analyses included current smokers aged 22 to 66 years who completed the SQ at both timepoints. The percent agreement of items and 95% confidence intervals were calculated for the comparisons between the two timepoints and between the SQ and the BRFSS questionnaire. To evaluate the feasibility of the SQ and to capture subjects’ opinions about the SQ, a meta-questionnaire was administrated. High test-retest reliability levels (percent agreement of > 70 to 100% between the two timepoints) were found for SQ smoking behavior items, in particular for items related to current smoking status, 100-cigarettes lifetime, regular smoking, age of initiation and preferred brand. Moderate (55% agreement) to high test-retest reliability (84% agreement) was found for daily consumption of manufactured cigarettes. The comparison between the SQ and the BRFSS 2011 showed a high concurrent validity (98 to 100% agreement). The SQ was completed on average in 3 to 4 min and was assessed as easy to use. The findings demonstrate that the SQ is reliable in smokers and a practical tool to assess smoking exposure in clinical studies.