Benchmarking a universal smoking machine adaptor for tobacco product testing.

SIGNIFICANCE: Characterisation of tobacco product emissions is an important step in assessing their impact on public health. Accurate and repeatable emissions data require that a leak-tight seal be made between the smoking or vaping machine and the mouth-end of the tobacco product being tested. This requirement is challenging because of the variety of tobacco product mouth-end geometries being puffed on by consumers today. We developed and tested a prototype universal smoking machine adaptor (USMA) that interfaces with existing machines and reliably seals with a variety of tobacco product masses and geometries. METHODS: Emissions were machine-generated using the USMA and other available adaptors for a variety of electronic cigarettes (n=7 brands), cigars (n=4), cigarillos (n=2), a heated tobacco product, and a reference cigarette (1R6F), and mainstream total particulate matter (TPM) and nicotine were quantified. Data variability (precision, n≥10 replicates/brand) for all products and error (accuracy) from certified values (1R6F) were compared across adaptors. RESULTS: TPM and nicotine emissions generated using the USMA were accurate, precise and agreed with certified values for the 1R6F reference cigarette. Replicate data indicate that USMA repeatability across all tobacco products tested generally meets or exceeds that from the comparison adaptors and extant data. CONCLUSION: The USMA seals well with a variety of combustible tobacco products, e-cigarettes with differing geometries and plastic-tipped cigarillos. Variability for all measures was similar or smaller for the USMA compared with other adaptors.

Hydrogen Cyanide and Aromatic Amine Yields in the Mainstream Smoke of 60 Little Cigars.

Mainstream smoke yields of hydrogen cyanide (HCN) and three aromatic amines, 1-aminonaphthalene, 2-aminonaphthalene, and 4-aminobiphenyl, from 60 little cigar brands currently on the US market were measured for both International Organization for Standardization (ISO) and Canadian Intense (CI) smoking regimens. The smoke yields are compared with those from 50 cigarette products measured by Counts et al. of Philip Morris USA (PMUSA) in 2005 [Counts et al. Regul. Toxicol. Pharmacol. 2005 41, 185-227] and 50 cigarette products measured by the Centers for Disease Control and Prevention (CDC) in cooperation with the Food and Drug Administration (FDA) in 2012 [Tynan et al. Consumption of Cigarettes and Combustible Tobacco: United States, 2000-2011. In Morbidity and Mortality Weekly Report; Centers for Disease Control and Prevention, 2012; 565-580]. For the little cigars, the average HCN yield with the ISO smoking regimen is 335 µg/cigar (range: 77-809 µg/cigar), which is 332% higher than the average of 50 PMUSA 2005 cigarettes and 243% higher than the average of 50 CDC/FDA 2012 cigarettes. For the CI smoking regimen, the average HCN yield is 619 µg/cigar (range: 464-1045 µg/cigar), which is 70.5% higher than the average of 50 PMUSA 2005 cigarettes and 69% higher than the average of the 50 CDC/FDA 2012 cigarettes. For aromatic amines, the average ISO smoking regimen smoke yields are 36.6 ng/cigar (range: 15.9-70.6 ng/cigar) for 1-aminonaphthalene, 24.6 ng/cigar (range: 12.3-36.7 ng/cigar) for 2-aminonaphthalene, and 5.6 ng/cigar (range: 2.3-17.2 ng/cigar) for 4-aminobiphenyl. The average ISO yields of aromatic amines from little cigars are 141% to 210% higher compared to the average yields of 50 PMUSA cigarettes. The average CI smoke regimen yields are 73.0 ng/cigar (range: 32.1-112.2 ng/cigar) for 1-aminonaphthalene, 45.2 ng/cigar (range: 24.6-74.8 ng/cigar) for 2-aminonaphthalene, and 12.7 ng/cigar (range: 5.5-37.5 ng/cigar) for 4-aminobiphenyl. The average CI aromatic amine yields are 143% to 220% higher compared to the average yields of 50 PMUSA cigarettes, almost identical to the relative yields under the ISO smoking regimen. Both HCN and aromatic amine yields are 1.5× to 3× higher for the tested little cigars than for the conventional cigarettes; however, there are notable differences in the relationships of these yields to certain product characteristics, such as weight, ventilation, and tobacco type. The higher smoke yields of these compounds from little cigars indicates that cigar smokers may be at risk of a higher exposure to HCN and aromatic amines on a per stick basis and thus increased health concerns.

Volatile Organic Compounds in Mainstream Smoke of Sixty Domestic Little Cigar Products.

The mainstream smoke yields of five volatile organic compounds (VOCs) were determined from 60 commercial U.S. little cigar products under ISO 3308 and Canadian Intense (CI) smoking regimens on linear smoking machines using a gas sampling bag collection. The five VOCs, 1,3-butadiene, acrylonitrile, benzene, isoprene, and toluene were analyzed using an automated GC/MS analytical method validated for measuring various VOCs in mainstream smoke. The VOCs range in amounts from micrograms to milligrams per little cigar. VOC deliveries vary considerably among the little cigar products under the ISO smoking regimen primarily due to varying filter ventilation. Under the CI smoking regimen where filter ventilation is blocked, the delivery range narrows, although individual and total VOC yields are approximately 2 fold higher than those under the ISO smoking regimen. Correlation analysis reveals strong associations between acrylonitrile and 1,3-butadiene or toluene under the ISO smoking regimen. Compared to cigarettes, little cigars delivered substantially higher VOC mainstream smoke yields under both ISO and CI smoking regimens. Moreover, little cigar smoke also contains higher VOCs than cigarette smoke when adjusted for mass of tobacco.

High-Performance Liquid Chromatography-Tandem Mass Spectrometry Analysis of Carbonyl Emissions from E-Cigarette, or Vaping, Products.

A quantitative method was developed to measure four harmful carbonyls (acetaldehyde, acrolein, crotonaldehyde, and formaldehyde) in aerosol generated from e-cigarette, or vaping, products (EVPs). The method uses a commercially available sorbent bed treated with a derivatization solution to trap and stabilize reactive carbonyls in aerosol emissions from EVPs to reduce reactive analyte losses and improve quantification. Analytes were extracted from the sorbent material using acetonitrile and analyzed via high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The method was applied to aerosols generated from products obtained from case patients with EVP use-associated lung injury (EVALI). The method accuracy ranged from 93.6 to 105% in the solvent and 99.0 to 112% in the matrix. Limits of detection (LODs) were in the low nanogram range at 0.735-2.10 ng for all analytes, except formaldehyde at 14.7 ng. Intermediate precision, as determined from the replicate measurements of quality-control (QC) samples, showed a relative standard deviation (RSD) of less than 20% for all analytes. The EVALI case-related products delivered aerosol containing the following ranges of carbonyls: acetaldehyde (0.0856-5.59 µg), acrolein (0.00646-1.05 µg), crotonaldehyde (0.00168-0.108 µg), and formaldehyde (0.0533-12.6 µg). At least one carbonyl analyte was detected in every product. Carbonyl deliveries from EVALI-associated products of all types are consistent with the previously published results for e-cigarettes, and levels are lower than those observed in smoke from combustible cigarettes. This method is rugged, has high throughput, and is well suited for quantifying four harmful carbonyls in aerosol emissions produced by a broad spectrum of devices/solvents, ranging from e-cigarette containing polar solvents to vaping products containing nonpolar solvents.

Alcohol, cocaine, and brain stimulation-reward in C57Bl6/J and DBA2/J mice.

BACKGROUND: Pleasure and reward are critical features of alcohol drinking that are difficult to measure in animal studies. Intracranial self-stimulation (ICSS) is a behavioral method for studying the effects of drugs directly on the neural circuitry that underlies brain reward. These experiments had 2 objectives: first, to establish the effects of alcohol on ICSS responding in the C57Bl6/J (C57) and DBA2/J (DBA) mouse strains; and second, to compare these effects to those of the psychostimulant cocaine. METHODS: Male C57 and DBA mice were implanted with unipolar stimulating electrodes in the lateral hypothalamus and conditioned to spin a wheel for reinforcement by the delivery of rewarding electrical stimulation (i.e., brain stimulation-reward or BSR). Using the curve-shift method, the BSR threshold (theta(0)) was determined immediately before and after oral gavage with alcohol (0.3, 0.6, 1.0, 1.7 g/kg) or water. Blood alcohol concentration (BAC) was measured to determine the influence of alcohol metabolism on BSR threshold. Separately, mice were administered cocaine (1.0, 3.0, 10.0, 30.0 mg/kg) or saline intraperitoneally. RESULTS: In C57 mice, the 0.6 g/kg dose of alcohol lowered BSR thresholds by about 20%, during the rising (up to 40 mg/dl), but not falling, phase of BAC. When given to the DBA mice, alcohol lowered BSR thresholds over the entire dose range; the largest reduction was by about 50%. Cocaine lowered BSR thresholds in both strains. However, cocaine was more potent in DBA mice than in C57 mice as revealed by a leftward shift in the cocaine dose-response curve. For both alcohol and cocaine, effects on BSR threshold were dissociable from effects on operant response rates. CONCLUSIONS: In C57 and DBA mice, reductions in BSR threshold reflect the ability of alcohol to potentiate the neural mechanisms of brain reward. The DBA mice are more sensitive to the reward-potentiating effects of both alcohol and cocaine, suggesting that there are mouse strain differences in the neural mechanisms of brain reward that can be measured with the ICSS technique.

Analysis of Titan tholin pyrolysis products by comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry.

The reddish brown haze that surrounds Titan, Saturn's largest moon, is thought to consist of tholin-like organic aerosols. Tholins are complex materials of largely unknown structure. The very high peak capacity and structured chromatograms obtained from comprehensive two-dimensional GC (GC x GC) are attractive attributes for the characterization of tholin pyrolysis products. In this report, GC x GC with time-of-flight MS detection and a flash pyrolysis inlet is used to characterize tholin pyrolysis products. Identified pyrolysis products include low-molecular-weight nitriles, alkyl substituted pyrroles, linear and branched hydrocarbons, alkyl-substituted benzenes and PAH compounds. The pyrolysis of standards found in tholin pyrolysate showed that little alteration occurred and thus these structures are likely present in the tholin material.

Rapid determination of complex mixtures by dual-column gas chromatography with a novel stationary phase combination and spectrometric detection.

Fast GC separations of a broad range of analytes are demonstrated using a capillary column coated with a novel immobilized ionic liquid (IIL) stationary phase. Both completely cross-linked and partially cross-linked columns were evaluated, yielding approximately 1600 and approximately 2000 theoretical plates per meter, respectively. Enhanced separation is demonstrated using a dual-column ensemble comprised of an IIL column, a commercially coated Rtx-1 column, and a pneumatic valve connecting the inlet to the junction point between the two columns. Enhanced separation of 20 components, with two sets of co-eluting peaks is shown in approximately 150 s, while sacrificing only a length of time equivalent to the sum of the stop flow pulses, or about 15.5 s. A novel application of a band trajectory model that shows band position as a function of analysis time as analytes move through the column ensemble is employed to determine pulse application times. The model predicts component retention times within a few seconds. Another method of selectivity enhancement of the IIL stationary phase-coated columns is demonstrated using a differential mobility spectrometer (DMS) that provides a second dimension separation based on ion mobility in a high-frequency electrical field. The DMS is able to separate all but one set of co-eluting components from the IIL column. The separation of 13 components found in the headspace above U.S. currency is demonstrated using the IIL column in a dual-column ensemble as well as with the DMS.

Band acceleration device for enhanced selectivity with tandem-column gas chromatography.

An electrically heated and air cooled metal sheath surrounding the first 50 cm of the second column in a series-coupled, capillary-column ensemble of a non-polar and a polar column is used to obtain enhanced isothermal separation of component pairs that are separated by the first column in the ensemble but co-elute from the ensemble by virtue of the different selectivity of the two columns. As the first of the two components passes into the second column, a current pulsed through the metal sheath rapidly heats the first 50 cm of the second column thus accelerating the band for the first component. Ensemble retention-time shifts of several seconds are easily obtained. The device is then rapidly cooled to quiescent oven temperature by a flow of pressured air through the space between the metal sheath and the fused silica capillary column and an additional flow through a larger, co-axial plastic tube. Both heating and cooling require only a few seconds. If substantial cooling of the device occurs before the band for the second component enters the device, the band experiences less thermally-induced acceleration with the result that the separation of the two targeted components is enhanced in the ensemble chromatogram with no significant change in the pattern of peaks for the other mixture components. If the device is cooled to a temperature below oven temperature before the arrival of the band for the second component, this band will be slowed, and further enhancement of separation is achieved in the ensemble chromatogram. A band trajectory model, based on retention factor versus temperature data for the two components in the two columns, is used to predict peak separation and to aid in the selection of temperature-pulse initiation times.

Orexin-1 receptor antagonism does not reduce the rewarding potency of cocaine in Swiss-Webster mice.

The orexin family of hypothalamic neuropeptides has been implicated in reinforcement mechanisms relevant to both food and drug reward. Previous behavioral studies with antagonists at the orexin A-selective receptor, OX(1), have demonstrated its involvement in behavioral sensitization, conditioned place-preference, and self-administration of drugs of abuse. Adult male Swiss-Webster mice were implanted with stimulating electrodes to the lateral hypothalamus and trained to perform intracranial self-stimulation (ICSS). The effects of the OX(1)-selective antagonist SB 334867 on brain stimulation-reward (BSR) and cocaine potentiation of BSR were measured. SB 334867 (10-30mg/kg, i.p.) alone had no effect on ICSS performance or BSR threshold. Cocaine (1.0-30mg/kgi.p.) dose-dependently potentiated BSR, measured as lowering of BSR threshold. This effect was not blocked by 30mg/kg SB 334867 at any cocaine dose tested. In agreement with previous reports, SB 334867 resulted in a reduction of body weight 24h after acute administration. Based on these data, it is concluded that orexins acting at OX(1) do not contribute to BSR; and are not involved in the reward-potentiating actions of cocaine on BSR. The data are discussed in the context of prior findings of SB 334867 effects on drug-seeking and drug-consuming behaviors.