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. Author manuscript; available in PMC: 2016 Jan 13.
Published in final edited form as: Tob Regul Sci. 2016;2(2):94–105. doi: 10.18001/TRS.2.2.1

Characterization of SPECTRUM Variable Nicotine Research Cigarettes

Patricia Richter 1, Pappas R Steven 2, Roberto Bravo 3, Joseph G Lisko 4, Maria Damian 5, Nathalie Gonzalez-Jimenez 6, Naudia Gray 7, Lisa M Keong 8, Jacob B Kimbrell 9, Peter Kuklenyik 10, Tameka S Lawler 11, Grace E Lee 12, Magaly Mendez 13, Jose Perez 14, Shakia Smith 15, Hang Tran 16, Robert Tyx 17, Clifford H Watson 18
PMCID: PMC4711912  NIHMSID: NIHMS750134  PMID: 26779559

Abstract

Objective

To provide researchers an extensive characterization of the SPECTRUM variable nicotine research cigarettes.

Methods

Data on cigarette physical properties, nicotine content, harmful and potentially harmful constituents in the tobacco filler was compiled.

Results

Data on physical properties, concentrations of menthol, nicotine and minor alkaloids, tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons, ammonia, and toxic metals in the filler tobacco for all available varieties of Spectrum research cigarettes are provided. The similarity in the chemistry and physical properties of SPECTRUM cigarettes to commercial cigarettes renders them acceptable for use in behavioral studies. Baseline information on harmful and potentially harmful constituents in research tobacco products, particularly constituent levels such as minor alkaloids that fall outside typical ranges reported for commercial, provide researchers with the opportunity to monitor smoking behavior and to identify biomarkers that will inform efforts to understand the role of nicotine in creating and sustaining addiction.

Conclusions

Well characterized research cigarettes suitable for human consumption are an important tool in clinical studies for investigating the physiological impacts of cigarettes delivering various levels of nicotine, the impact of reduced nicotine cigarettes on nicotine addiction, and the relationship between nicotine dose and smoking behavior.

Keywords: tobacco, cigarettes, spectrum, nicotine, alkaloids, metals, PAH

INTRODUCTION

The 22nd Century Group, Inc. uses a combination of techniques including genetic engineering and plant breeding to provide cigarette tobacco filler with reduced nicotine content. The 22nd Century Group manufactured variable nicotine cigarettes under subcontract with the Research Triangle Institute (RTI).1 The modified nicotine cigarettes include a minimal (placebo) nicotine delivery level, menthol and non-mentholated varieties, and eight target nicotine delivery levels. The products also differ in tar deliveries, ventilation, and levels of other constituents. A total of 23 cigarette configurations are made available to researchers through NIDA’s Drug Supply Program under the name, “SPECTRUM.”1,2

Unlike other research tobacco products, SPECTRUM cigarettes provide researchers with a variable nicotine cigarette that is “suitable” for smoking by human test subjects.3 Some research incorporating SPECTRUM cigarettes has already been published and more is expected due to multiple funding opportunities intended to facilitate research that will help inform the U.S. Food and Drug Administration in priority research areas including dependence thresholds and the impact of nicotine reduction on tobacco product use behavior.3–5

Nicotine addiction and its relation to smoking behavior is complex. The manner in which a smoker utilizes the product and levels of chemical constituents in tobacco and smoke determine the exposure to smoke constituents.6 In addition to general considerations of toxicity, some tobacco smoke constituents like acetaldehyde7 are also thought to be a factor in addiction. Therefore additional data on the characterization of the SPECTRUM cigarettes will inform researchers using variable nicotine cigarettes in behavioral, addiction, exposure biomonitoring, cessation, and other tobacco-related studies.

We report here an extensive characterization of physical properties and constituent levels for SPECTRUM variable nicotine research cigarettes. This characterization includes the physical properties of the cigarettes (length, pressure drop, filter ventilation, filter circumference, rod circumference, filter length, tobacco length, over wrap length, air permeability, and tobacco weight and cigarette weight) as well as menthol, nicotine, minor alkaloids, and several major classes of harmful and potentially harmful organic and inorganic chemical constituents in the tobacco.

METHODS

Twenty-three varieties of SPECTRUM research cigarettes were obtained from NIDA (Bethesda, MD, USA) in 2014 and stored in original packaging after receipt.

Results are reported on an “as received” basis unless otherwise noted.

Physical properties

After conditioning the cigarettes according to ISO 3402 (1999) specifications, physical property determinations were performed using a C2 instrument (Cerulean, Milton Keynes, UK). Five replicate measurements were made on each cigarette variety to determine cigarette length, pressure drop, filter ventilation, filter circumference, rod circumference, filter length, tobacco length, and over wrap length. Air permeability was determined using a PPM1000M instrument (Cerulean, Milton Keynes, UK).

Tobacco filler and cigarette weights were determined manually with calibrated and certified balances.

Quantitative analytical measurements

All quantitative methods were performed in a strict QA/QC environment. Each analytical method below has been full validated and has sufficient dynamic range for all samples. The limits of detections for each method was obtained using Taylor’s method.8 All reported data fall between the lowest and highest calibration curve point. Any measured values lower than the lowest calibration point are reported as non-detects. All run QC were checked using a modified Westgard protocol.9 Any QC failures were excluded and samples repeated if needed. All data were reviewed by a quality control officer and quality manager prior to release.

Menthol

Previously unopened packages of cigarettes were used for menthol analysis to minimize substantial evaporative losses. Sample preparation procedures were described previously.10 Tobacco menthol levels were determine analytically using an Agilent 7890 GC coupled with a 5975 MSD (Agilent Technologies; Newark, DE, USA). The chromatographic separation was achieved using an Ultra-2 capillary column (25m × 0.32mm × 0.52µM, Agilent Technologies; Andover, MA, USA) with research grade helium carrier gas as previously described.10 Results are the mean and standard deviations of five replicate analyses.

Tobacco specific nitrosamines

Tobacco filler from individual cigarettes was removed from the paper wrapper and ground to uniformity with a Cuisinart® Spice and Nut grinder. For each cigarette type, five 0.25 g aliquots of the ground filler were measured into 15 mL amber vials and spiked with 100 µL internal standard solution, representing 100 ng 13C labeled standard for each analyte. Ten mL of 100 mM aqueous ammonium acetate solution was added to each sample and shaken for 60 minutes at 250 rpm on a Benchmark IncuShaker 10 L (Benchmark Scientific, Edison, NJ, USA) Approximately 0.5 mL of the extract was pipetted into a Thompson Filter Vial and press-filtered at 0.45 µm.

Analytical separation was performed on an Agilent 1200 G1312B binary pump. (Agilent Technologies, Santa Clara, CA) using a 5µm particle size Xterra MS C18 4.6 × 50mm HPLC column (Waters Corporation, Milford, MA, USA) with mobile phase pumped at 1 mL/min at 60°C. Elution began with 95% solution A (5mM aqueous ammonium acetate), 5% solution B (95% acetonitrile, 5% water with 5mM ammonium acetate) mobile phase for 1 min, followed by a 1 min gradient to 65% solution A, 35% solution B. The mobile phase was maintained at 65% solution A, 35% solution B for 3 min, followed by a 2 min gradient to the original mobile phase. Analytes were quantitated with an API 4000 triple quadrupole mass spectrometer (Sciex Corporation, Farmington MA, USA) working in positive electrospray ionization mode as previously described.11 Tandem mass spectrometry data was evaluated and quantitated using Sciex Analyst 1.5 software.

Alkaloids

Analyses of alkaloids were performed using an Agilent 7890 GC coupled with a 7000 Triple-Quad detector (Agilent Technologies, Newark, DE, USA). The chromatographic separation was accomplished using a DB-1701 capillary column (30m × 0.250 µM, 0.25 µM, J&W Scientific) with research grade helium used as the carrier gas as previously described.12 Results are the mean and standard deviations of five replicate analyses (N = 5).

Polycyclic Aromatic Hydrocarbons

Tobacco filler from individual cigarettes were weighed, spiked with an isotopically labeled13C-PAH mixture as an internal standard, extracted with 10 ml cyclohexane followed by evaporation to 1 ml. Extracts were filtered through a 0.45 µM Nylon syringe filter. The PAHs were subsequently analyzed by SIM GC/MS, normalized to tobacco weight and expressed in nanograms of analyte per gram tobacco. Analytes measured included acenaphthene (ACE), acenaphthylene (ACL), anthracene (ANT), benzo[a]pyrene (BAP), benzo[e]pyrene (BEP), chrysene (CHR), fluoranthene (FLR), fluorene (FLU), naphthalene (NAP), phenanthrene (PHE), pyrene (PYR), benz[a]anthracene (BAA), benzo[b]fluoranthene (BBF), and benzo[k]fluoranthene (BKF). Lowest reportable levels were determined as the concentration of the lowest standards for each analyte. Five replicates were analyzed for each variety.

Nicotine

Tobacco filler from individual cigarettes was removed from the paper wrapper, 5 mL of 2N NaOH was added to 1.0 grams of tobacco filler in a 60 mL amber vial, followed by extraction with 50 mL of an MTBE stock that contained quinoline as an internal standard. A 1 mL aliquot of the extract was placed in a 2 mL amber vial for GC/MS analysis. The sample preparation and nicotine analytical method have been previously described.13 Five replicates were analyzed for each variety.

Ammonia

Tobacco filler from individual cigarettes was removed from the paper wrapper, placed into a 60-mL amber bottle, and weighed. Deionized water (30 mL) was added and the sample was sealed with a PTFE-lined cap. The sample was shaken for 30 min at 160 rpm on a Max Q 2000 shaker (Barnstead/Labline, Dubuque, IA, USA). A 1.5mL sample aliquot was centrifuged in a Sorval Pico Biofuge (Thermo Fisher, Waltham, MA, USA) at 13,000 rpm for 5 min to remove tobacco debris. A 10:1 water to sample dilution was made in a 1.5 mL sample vial. The sample was vortexed and placed in a sample tray for analysis. Five replicates were analyzed for each variety.

An ISO Guide 34 1000 mg/L ammonium standard was purchased from Sigma Aldrich (St. Louis, MO, USA). Ultrapure water used in all procedures was from an Aqua Solutions water system (Aqua Solutions, Jasper, GA, USA).

Samples (25 µL injections) were analyzed with a Dionex ICS-3000 chromatography system with Chromeleon version 6.8 software and a 4 mm Ion Pac CS12A cation exchange column (Thermo Scientific, Sunnyvale, CA, USA). Isocratic separation of the ammonium ion was achieved using a 20 mM methanesulfonic acid eluent prepared by the EG40 eluent generator with cation self-regenerating suppressor that required only an ultrapure water source in order to suppress the conductance from the eluent (Thermo Scientific, Sunnyvale, CA USA). The column temperature was maintained at 25°C with a run time of 15 minutes. Ammonium ions were detected using a conductivity detector.

Inorganic Constituents

Tobacco filler from 4 individual cigarettes of each variety was removed from the paper wrapper and combined for analysis. The tobacco was dried for 3 hours at 90°C and rendered more homogeneous by grinding for 20 seconds with a Smart Grind coffee grinder (Black and Decker, Middleton, WI, USA). Samples (0.100 to 0.150 g) were digested with a Milestone Ethos microwave system and analyzed with “Triple Quad” Inductively Coupled Plasma Mass Spectrometry as previously described.14 Dried tobacco was analyzed for mercury using a combustion mercury analyzer as previously described15 with minor modification.16 Quality control was maintained throughout using Reference tobacco 1S3 (North Carolina State University, Raleigh, NC, USA) and certified reference material (CRM) CTA-OTL-1 (Instytucie Chemii i Techniki Jadrowej, Warszawa, Poland) as previously described.14,16 Results are reported as the mean and standard deviations of 5 replicate analyses.

RESULTS

Physical Properties

Based on physical properties, the cigarette paper seemed consistent for all SPECTRUM varieties. Cigarette diameter, circumference, tip length (Table 1), and paper porosity differed negligibly from variety to variety. The average paper porosity for all SPECTRUM cigarette varieties was 31.5 ± 3.7 CORESTA units. All measured physical properties are in Tables 1 and 2.

Table 1.

SPECTRUM Cigarette Physical Parameters

Product
Code		 Cigarette
Mass
(mg)		 Diameter
(mm)		 Circumference
(mm)		 Filter
Length
(mm)		 Tip
Length
(mm)		 Overwrap
Length
(mm)
NRC100 970 ± 18 7.93 ± 0.03 24.93 ± 0.08 22.6 ± 0.3 30.3 ± 0.3 7.7 ± 0.1
NRC101 934 ± 31 7.96 ± 0.01 25.00 ± 0.04 22.6 ± 0.6 30.3 ± 0.5 7.7 ± 0.1
NRC102 897 ± 20 7.95 ± 0.03 24.98 ± 0.09 22.7 ± 0.6 30.4 ± 0.7 7.7 ± 0.1
NRC103 913 ± 25 7.92 ± 0.02 24.88 ± 0.06 22.8 ± 0.4 31.2 ± 0.9 8.4 ± 1.3
NRC104 946 ± 28 7.91 ± 0.01 24.83 ± 0.03 25.1 ± 1.8 30.5 ± 0.1 5.4 ± 1.8
NRC105 898 ± 22 7.91 ± 0.01 24.86 ± 0.03 23.0 ± 0.5 30.3 ± 0.1 7.4 ± 0.5
NRC200 939 ± 35 7.93 ± 0.01 24.93 ± 0.02 22.6 ± 0.2 30.1 ± 0.1 7.5 ± 0.1
NRC201 933 ± 59 7.94 ± 0.02 24.95 ± 0.08 22.8 ± 0.4 30.4 ± 0.3 7.7 ± 0.1
NRC300 979 ± 21 7.94 ± 0.01 24.96 ± 0.04 22.7 ± 0.2 30.8 ± 1.5 8.0 ± 1.6
NRC301 890 ± 16 7.96 ± 0.01 25.00 ± 0.02 22.3 ± 0.6 30.7 ± 1.2 8.4 ± 1.2
NRC302 894 ± 9 7.87 ± 0.02 24.73 ± 0.07 24.9 ± 1.7 30.4 ± 0.3 5.5 ± 1.7
NRC400 969 ± 20 7.95 ± 0.01 24.97 ± 0.05 22.6 ± 0.3 31.9 ± 2.0 9.3 ± 2.2
NRC401 944 ± 21 7.89 ± 0.02 24.77 ± 0.06 22.5 ± 0.3 30.9 ± 1.6 8.5 ± 1.3
NRC402 950 ± 32 7.90 ± 0.01 24.83 ± 0.04 23.0 ± 0.7 30.3 ± 0.1 7.3 ± 0.7
NRC404 915 ± 33 7.93 ± 0.01 24.91 ± 0.04 23.2 ± 0.1 30.5 ± 0.7 7.3 ± 0.8
NRC405 875 ± 48 7.89 ± 0.01 24.79 ± 0.03 23.0 ± 0.4 30.4 ± 0.1 7.4 ± 0.5
NRC500 935 ± 29 7.90 ± 0.01 24.81 ± 0.02 22.5 ± 0.5 30.1 ± 0.2 7.5 ± 0.6
NRC501 975 ± 22 7.93 ± 0.02 24.91 ± 0.05 22.5 ± 0.2 30.2 ± 0.4 7.7 ± 0.4
NRC600 973 ± 35 7.90 ± 0.02 24.81 ± 0.06 25.1 ± 2.1 31.3 ± 1.6 6.2 ± 2.1
NRC601 936 ± 16 7.91 ± 0.02 24.86 ± 0.05 23.3 ± 0.8 30.7 ± 0.4 7.4 ± 0.5
NRC602 920 ± 46 7.89 ± 0.02 24.79 ± 0.05 23.7 ± 1.3 30.4 ± 0.1 6.6 ± 1.4
NRC700 956 ± 34 7.90 ± 0.02 24.82 ± 0.06 23.5 ± 1.0 30.5 ± 0.4 7.0 ± 0.7
NRC701 971 ± 37 7.91 ± 0.01 24.85 ± 0.04 23.1 ± 0.4 30.7 ± 0.3 7.7 ± 0.1
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Table 2.

SPECTRUM Cigarette Physical Parameters

Product
Code		 Pressure
Drop (Vents
Open) (mm
WG)		 Pressure
Drop (Vents
Closed)
(mm WG)		 Tip
Ventilation
(%)		 Total
Ventilation
(%)		 Tobacco
Length
(mm)		 Tobacco
Mass
(mg)		 Rod
Length
(mm)
NRC100 77.1 ± 3.4 153 ± 9 58.3 ± 3.6 64.9 ± 3.4 60.7 ± 0.2 692 ± 20 83.3 ± 0.2
NRC101 72.8 ± 3.7 147 ± 7 60.7 ± 0.9 66.0 ± 0.8 60.6 ± 0.7 655 ± 29 83.2 ± 0.2
NRC102 114 ± 10 131 ± 13 15.4 ± 1.2 30.6 ± 3.3 60.5 ± 0.6 619 ± 21 83.2 ± 0.2
NRC103 128 ± 7 149 ± 9 16.5 ± 1.0 29.1 ± 2.5 60.3 ± 0.5 630 ± 25 83.1 ± 0.2
NRC104 112 ± 4 112 ± 4 0.6 ± 0.1 14.6 ± 1.6 58.9 ± 1.8 688 ± 23 84.0 ± 0.2
NRC105 120 ± 7 120 ± 7 0.5 ± 0.1 17.0 ± 1.8 60.2 ± 0.5 662 ± 22 83.2 ± 0.2
NRC200 132 ± 6 157 ± 12 18.2 ± 2.6 31.6 ± 3.5 60.0 ± 0.3 661 ± 36 83.4 ± 0.1
NRC201 135 ± 4 157 ± 5 16.6 ± 1.1 30.4 ± 2.0 60.4 ± 0.4 653 ± 59 83.2 ± 0.1
NRC300 130 ± 2 152 ± 3 16.4 ± 1.2 30.6 ± 1.9 60.1 ± 0.1 700 ± 18 82.8 ± 0.2
NRC301 123 ± 9 144 ± 12 16.9 ± 0.9 29.7 ± 2.3 60.7 ± 0.7 612 ± 13 82.9 ± 0.2
NRC302 105 ± 7 105 ± 7 0.8 ± .0.1 13.8 ± 1.5 59.0 ± 1.7 662 ± 13 83.9 ± 0.2
NRC400 122 ± 4 138 ± 3 14.2 ± 1.4 25.7 ± 1.4 60.6 ± 0.3 691 ± 20 83.2 ± 0.1
NRC401 144 ± 9 161 ± 10 13.0 ± 1.5 27.0 ± 3.0 61.4 ± 0.3 666 ± 22 83.8 ± 0.1
NRC402 134 ± 9 145 ± 9 10.2 ± 1.3 25.4 ± 2.6 61.1 ± 0.5 694 ± 34 84.1 ± 0.3
NRC404 112 ± 6 112 ± 6 0.7 ± 0.1 17.7 ± 1.5 59.7 ± 0.4 680 ± 36 83.0 ± 0.3
NRC405 108 ± 4 108 ± 4 0.5 ± 0.1 13.9 ± 2.5 60.6 ± 0.7 640 ± 48 83.6 ± 0.3
NRC500 121 ± 5 126 ± 5 4.7 ± 5.2 15.6 ± 2.1 61.2 ± 0.3 680 ± 32 83.8 ± 0.4
NRC501 118 ± 4 137 ± 5 15.8 ± 0.5 25.8 ± 1.2 60.7 ± 0.3 693 ± 24 83.2 ± 0.1
NRC600 116 ± 5 131 ± 5 13.8 ± 0.7 27.3 ± 2.9 58.9 ± 2.1 693 ± 37 84.0 ± 0.3
NRC601 127 ± 4 141 ± 4 11.9 ± 1.7 23.0 ± 2.8 60.8 ± 0.7 657 ± 15 84.1 ± 0.1
NRC602 103 ± 5 103 ± 6 0.6 ± 0.1 14.4 ± 1.9 60.1 ± 1.2 685 ± 44 83.8 ± 0.2
NRC700 113 ± 4 119 ± 4 7.2 ± 1.2 17.6 ± 1.9 60.8 ± 0.9 698 ± 28 84.3 ± 0.1
NRC701 121 ± 8 138 ± 8 15.7 ± 0.8 24.0 ± 1.0 60.8 ± 0.5 693 ± 38 83.9 ± 0.2
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Mean and standard deviation of quintuplicate measurements

Menthol Results

Menthol concentrations varied greatly among the SPECTRUM cigarettes. Twelve mentholated products (NRC101, NRC103, NRC105, NRC201, NRC301, NRC302, NRC401, NRC405, NRC501, NRC601, NRC602, and NRC701) had menthol concentrations ranging from 4970 – 7540 µg menthol/cigarette. Non-mentholated products had measured menthol concentrations ranging from 1.1 – 114.0 µg/cigarette. Both of these ranges were consistent with menthol concentrations recently reported for commercial menthol and non-menthol cigarette brands sold in the United States.17 Results are reported in Table 3.

Table 3.

Menthol and TSNA Concentrations in the Tobacco of SPECTRUM Cigarettes (Columns 2 and 4)

Product Code Menthol (µg/g) Menthol (µg/cig) NNN (ng/g) NNK (ng/g)
NRC100 14.5 ± 1.4 14.0 1026 ± 37 52.0 ± 3.3
NRC101* 7480 ± 511 6760 1030 ± 19 49.7 ± 3.7
NRC102 11.3 ± 2.0 1.1 996 ± 21 47.8 ± 4.6
NRC103* 6720 ± 763 5980 963 ± 23 45.2 ± 3.0
NRC104 5.6 ± 0.7 5.3 972 ± 37 54.3 ± 4.2
NRC105* 7400 ± 754 6490 1013 ± 14 49.7 ± 3.2
NRC200 14.9 ± 0.5 14.7 995 ± 7 68.2 ± 3.5
NRC201* 6680 ± 545 6350 1002 ± 32 75.6 ± 6.9
NRC300 13.5 ± 0.3 13.3 1091 ± 45 93.9 ± 6.8
NRC301* 5550 ± 412 4970 1108 ± 122 88.0 ± 4.6
NRC302* 8860 ± 812 7690 1030 ± 20 75.9 ± 4.1
NRC400 9.3 ± 0.8 9.0 1217 ± 11 156 ± 7
NRC401* 6380 ± 796 6150 1244 ± 40 152 ± 6
NRC402 8.6 ± 0.6 8.2 1272 ± 104 200 ± 47
NRC404 122 ± 17 114 1254 ± 12 197 ± 11
NRC405* 8610 ± 751 7720 1148 ± 75 156 ± 19
NRC500 8.7 ± 0.9 8.1 1322 ± 50 184 ± 5
NRC501* 5540 ± 646 5470 1475 ± 28 243 ± 31
NRC600 11.1 ± 0.8 10.9 1732 ± 75 262 ± 22
NRC601* 7540 ± 764 7130 1591 ± 89 249 ± 22
NRC602* 7960 ± 789 7540 1543 ± 43 232 ± 14
NRC700 8.4 ± 0.9 8.7 1616 ± 90 517 ± 140
NRC701* 7170 ± 773 7350 1506 ± 39 302 ± 18
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(Mean ± standard deviation of quintuplicate analyses of each product). Columns 4 and 5: Nitrosamine concentrations in the tobacco of SPECTRUM cigarettes (Mean ± SD of quintuplicate analyses of each product).

*

Mentholated products.

Nitrosamines

Results for NNN (N-nitrosonornicotine) and NNK (4-(N-nitrosomethylamino)-1-(3-pyridyl)-1-butanone) were reported in Table 3. NNN concentrations ranged from 963 ng/g to 1732 ng/g, NNK values were 45.2 ng/g to 517 ng/g. As expected, concentrations of NNN in the tobacco filler were higher than that of NNK. These results place the NNN levels of SPECTRUM cigarettes within the lower third of the concentration range reported for commercial cigarette products.18 The majority of SPECTRUM NNK values were lower than the lowest NNK level (330 ng/g) published by Stepanov et al.18

Polycyclic Aromatic Hydrocarbons

Although PAHs are primarily combustion products, difference in tobacco processing, ie, curing practices, can result in PAHs being present in tobacco filler. The results for analyses of PAHs in the tobacco from SPECTRUM cigarettes are reported in Table 4. Of the 14 PAHs analyzed, 8 PAH compounds were present at detectable levels ranging from 0.57 – 349 ng/g. No detectable levels of BAP, ACL, FLU, ANT, BAA, or NAP were found in the SPECTRUM cigarettes. The highest PAH concentrations were found for CHR (193 – 349 ng/g) and PHE (32.7 – 59.7ng/g), which were detected in all of the products analyzed. The compounds PYR (8.47 – 16.6 ng/g) and FLR (7.78 – 11.8 ng/g) had lower levels but were detectable in all of the varieties tested. Little data on PAH concentrations in cigarette filler tobacco has been published since fire-cured tobacco is not commonly used for filler. However, phenanthrene and chrysene, concentrations in all Spectrum variety tobacco fillers were higher than the respective concentrations determined in 3R4F (used as a quality control, 26.3 ng/g and 3.7 ng/g, respectively), whereas fluoranthene, benzo[e]pyrene and benzo[a]pyrene concentrations were lower in all Spectrum variety tobacco fillers than in 3R4F (15.7 ng/g, 2.0 ng/g, and 1.3 ng/g, respectively).

Table 4.

Detectable PAH Concentrations (ng/g) From Quintuplicate Analyses of Spectrum Cigarettes.

ACE PHE FLR PYR CHR BBF BKF BEP BAP
NRC100 <LOD 51.3±6.7 10.6±0.71 14.5±0.6 323±6 2.96±1.68 0.92±0.41 0.57±0.52 <LOD
NRC101 <LOD 49.1±11.1 10.2±0.91 14.0±1.4 265±45 3.39±1.53 1.24±0.37 <LOD <LOD
NRC102 3.34±0.64 52.3±5.6 11.8±0.65 13.5±0.8 349±16 3.10±1.83 0.94±0.52 <LOD <LOD
NRC103 3.60±0.27 53.4±4.5 9.94±0.44 14.6±0.4 318±30 1.49±0.83 0.99±0.36 <LOD <LOD
NRC104 <LOD 51.7±8.6 10.8±0.93 16.2±1.0 315±10 2.02±0.82 <LOD <LOD <LOD
NRC105 3.74±0.13 49.7±6.4 9.93±0.78 14.8±0.8 317±8 2.07±0.93 <LOD <LOD <LOD
NRC200 3.20±0.26 52.5±9.3 9.55±0.72 14.4±0.7 319±12 2.35±0.78 <LOD <LOD <LOD
NRC201 3.45±0.14 56.4±8.5 9.91±1.17 15.0±0.9 306±32 2.29±0.54 0.71±0.14 <LOD <LOD
NRC300 <LOD 58.5±8.8 9.61±1.20 14.1±1.2 285±34 1.17±0.31 <LOD <LOD <LOD
NRC301 <LOD 59.7±10.6 8.43±1.16 13.3±0.4 303±51 1.80±1.58 <LOD <LOD <LOD
NRC302 <LOD 58.1±9.3 10.3±0.63 14.6±1.4 283±63 1.62±1.02 <LOD <LOD <LOD
NRC401 4.23±0.27 47.1±4.1 10.2±0.79 15.3±1.1 234±21 <LOD <LOD 0.64±0.27 <LOD
NRC402 3.99±0.29 47.5±5.9 11.6±0.41 16.3±0.7 260±9 <LOD <LOD <LOD <LOD
NRC404 3.50±1.63 45.3±9.5 9.82±0.44 16.6±1.4 193±8 1.77±0.31 <LOD <LOD <LOD
NRC405 <LOD 42.4±3.0 10.9±0.35 15.7±0.9 239±27 1.20±0.54 <LOD <LOD <LOD
NRC500 3.59±0.24 51.6±6.2 11.4±1.03 14.8±0.3 261±7 <LOD <LOD <LOD <LOD
NRC501 3.80±0.09 50.4±3.6 10.0±0.65 12.7±1.4 259±5 <LOD <LOD <LOD <LOD
NRC600 <LOD 32.7±6.9 8.06±0.61 11.5±0.6 220±27 <LOD <LOD <LOD <LOD
NRC601 <LOD 37.7±6.5 8.89±0.49 11.3±0.5 240±9 <LOD <LOD <LOD <LOD
NRC602 3.59±0.29 40.1±1.1 10.3±0.36 12.3±1.3 254±5 <LOD <LOD <LOD <LOD
NRC700 <LOD 46.5±12.5 8.39±0.95 8.47±0.7 339±14 5.10±3.09 1.46±1.03 <LOD <LOD
NRC701 <LOD 41.4±5.5 7.78±0.76 8.75±1.1 316±53 4.12±1.86 1.53±0.51 <LOD <LOD
LOD > 3.15 9.94 5.65 0.03 2.03 1.06 0.63 0.42 1.02
Low Std Calibrator > 2.57 8.97 4.57 3.37 1.86 0.96 0.41 0.33 0.83
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Key: Acenaphthene (ACE), benzo[a]pyrene (BAP), benzo[e]pyrene (BEP), chrysene (CHR), fluoranthene (FLR), phenanthrene (PHE), and pyrene (PYR), benzo[b]fluoranthene (BBF), benzo[k]fluoranthene (BKF)

Nicotine and Minor Alkaloids

The results of analyses for nicotine and minor alkaloids (nornicotine, myosmine, anabasine, anatabine, and isonicotine are reported in Table 5. Nicotine concentrations ranged from very low to within the range reported for commercial products (0.28 – 25.0 mg/g). The majority of products had nicotine concentrations that were well below the levels of comparable commercial cigarette products,19 which typically range from 8 – 22 mg/g, indicating a selective reduction of nicotine. Overall concentrations of other alkaloids were higher than those found in commercial products12 and generally increased with measured nicotine concentration for each SPECTRUM product type. Alkaloid concentration ranges for the SPECTRUM varieties were 472 – 1235 µg/g for nornicotine, 14.8 – 28.7 µg/g for myosmine, 5.9 – 242.4 µg/g for anabasine, 29.7 – 2124 µg/g for anatabine and 3.2 – 64.9 µg/g for isonicotine.

Table 5.

Nicotine and minor alkaloid concentrations

Product
Code		 NIC (mg/g) NNIC (µg/g) MYOS (µg/g) ANAB
(µg/g)		 ANAT
(µg/g)		 ISONIC
(µg/g)
NRC100 0.31 ± 0.01 508 ± 29 16.5 ± 1.1 6.7 ± 0.3 32.6 ± 2.9 3.6 ± 0.2
NRC101 0.31 ± 0.00 534 ± 40 18.1 ± 1.4 6.7 ± 0.5 33.1 ± 2.7 3.5 ± 0.2
NRC102 0.31 ± 0.01 512 ± 21 16.2 ± 1.1 6.5 ± 0.4 31.7 ± 2.7 3.4 ± 0.2
NRC103 0.28 ± 0.01 472 ± 24 14.8 ± 1.0 5.9 ± 0.4 29.7 ± 2.7 3.2 ± 0.1
NRC104 0.33 ± 0.01 478 ± 20 15.9 ± 1.4 6.0 ± 0.3 30.3 ± 1.9 3.7 ± 0.2
NRC105 0.31 ± 0.01 553 ± 50 18.0 ± 1.1 6.9 ± 0.4 33.9 ± 2.9 3.4 ± 0.1
NRC200 0.93 ± 0.03 498 ± 32 15.5 ± 1.0 12.6 ± 2.7 78.0 ± 5.3 5.3 ± 0.2
NRC201 1.00 ± 0.03 534 ± 18 15.4 ± 1.4 13.0 ± 1.8 84.6 ± 14 5.5 ± 0.4
NRC300 1.90 ± 0.05 520 ± 28 14.8 ± 1.4 20.1 ± 2.5 139 ± 16 8.0 ± 0.4
NRC301 1.97 ± 0.03 544 ± 23 16.0 ± 2.1 21.1 ± 3.6 142 ± 26 8.0 ± 0.2
NRC302 2.05 ± 0.03 593 ± 58 18.3 ± 1.9 21.5 ± 2.5 162 ± 19 8.5 ± 0.5
NRC400 4.57 ± 0.07 632 ± 48 18.6 ± 2.0 47.0 ± 4.8 330 ± 37 14.2 ± 1.1
NRC401 4.81 ± 0.16 670 ± 73 18.4 ± 2.0 54.8 ± 10.3 378 ± 71 14.5 ± 1.3
NRC402 5.36 ± 0.12 681 ± 60 20.0 ± 2.0 53.9 ± 12.4 415 ± 83 18.3 ± 1.6
NRC404 7.06 ± 0.15 711 ± 52 18.2 ± 2.2 67.1 ± 10.4 489 ± 79 19.9 ± 2.1
NRC405 5.19 ± 0.09 729 ± 98 20.5 ± 1.3 55.6 ± 6.8 432 ± 41 18.1 ± 1.3
NRC500 11.1 ± 0.1 765 ± 60 19.8 ± 1.4 101 ± 10 814 ± 89 30.5 ± 2.1
NRC501 10.0 ± 0.2 786 ± 40 17.8 ± 3.3 113 ± 16 825 ± 108 29.9 ± 4.7
NRC600 15.7 ± 0.3 1020 ± 94 19.5 ± 2.5 163 ± 19 1344 ± 151 41.8 ± 4.0
NRC601 17.3 ± 0.6 1235 ± 133 28.7 ± 5.7 205 ± 47 1683 ± 368 54.6 ± 9.9
NRC602 14.2 ± 0.5 1070 ± 136 24.8 ± 3.5 178 ± 24 1464 ± 190 44.5 ± 4.9
NRC700 23.4 ± 0.6 1218 ± 157 22.2 ± 2.7 242 ± 39 2124 ± 331 64.9 ± 6.7
NRC701 25.0 ± 1.2 1221 ± 110 20.6 ± 1.1 231 ± 49 2027 ± 418 61.1 ± 6.6
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(Mean ± standard deviation of quintuplicate analyses of each product).

Key: NIC = nicotine, NNIC = nornicotine, MYOS = myosmine, ANAB = anabasine, ANAT = anatabine, ISONIC = isonicotine.

Inorganic Analytes

Ammonia levels in the tobacco filler differed little between the cigarette varieties, ranging from 2.2 to 3.7 mg ammonia per gram of conditioned tobacco filler (Table 6). Within-variety replicate measurements showed little variation with relative standard deviations ranging from 1.6 to 5.6 %. This range is in line with previously reported ammonia concentrations in tobacco filler.20

Table 6.

Ammonia and Toxic Metal and Metalloid Concentrations in SPECTRUM Cigarette Filler Tobacco

Product Code NH3 mg/g Be (µg/g) Cr (µg/g) Mn (µg/g) Co (µg/g) Ni (µg/g) As (µg/g) Se (µg/g) Cd (µg/g) Hg (µg/g) Pb (µg/g) U (µg/g)
NRC100 3.3 ± 0.2 0.016 ± 0.002 1.08 ± 0.08 153 ± 2 0.51 ± 0.07 1.76 ± 0.19 0.105 ± 0.008 0.077 ± 0.008 0.97 ± 0.05 0.0234 ± 0.0007 0.82 ± 0.07 0.028 ± 0.002
NRC101 3.4 ± 0.1 0.015 ± 0.002 0.89 ± 0.03 158 ± 3 0.49 ± 0.04 1.53 ± 0.08 0.105 ± 0.010 0.080 ± 0.012 0.96 ± 0.04 0.0237 ± 0.0007 0.64 ± 0.04 0.026 ± 0.004
NRC102 3.3 ± 0.1 0.018 ± 0.001 1.00 ± 0.15 154 ± 5 0.49 ± 0.03 1.61 ± 0.15 0.114 ± 0.012 0.072 ± 0.006 0.91 ± 0.04 0.0235 ± 0.0007 0.63 ± 0.03 0.027 ± 0.003
NRC103 3.7 ± 0.1 0.018 ± 0.002 0.94 ± 0.18 210 ± 9 0.57 ± 0.04 1.57 ± 0.13 0.104 ± 0.012 0.090 ± 0.007 1.00 ± 0.06 0.0209 ± 0.0004 0.57 ± 0.07 0.024 ± 0.001
NRC104 3.5 ± 0.2 0.017 ± 0.002 1.05 ± 0.16 197 ± 11 0.52 ± 0.04 1.67 ± 0.18 0.118 ± 0.009 0.080 ± 0.015 0.96 ± 0.04 0.0210 ± 0.0005 0.58 ± 0.03 0.025 ± 0.002
NRC105 3.3 ± 0.1 0.018 ± 0.002 0.98 ± 0.09 208 ± 5 0.58 ± 0.03 1.73 ± 0.13 0.109 ± 0.003 0.078 ± 0.008 0.98 ± 0.03 0.0217 ± 0.0004 0.59 ± 0.06 0.025 ± 0.001
NRC200 3.5 ± 0.1 0.017 ± 0.003 1.21 ± 0.13 222 ± 3 0.58 ± 0.05 1.73 ± 0.17 0.113 ± 0.010 0.087 ± 0.006 1.00 ± 0.02 0.0211 ± 0.0007 0.55 ± 0.05 0.025 ± 0.002
NRC201 3.4 ± 0.1 0.018 ± 0.002 1.21 ± 0.09 211 ± 5 0.58 ± 0.05 1.78 ± 0.23 0.116 ± 0.010 0.088 ± 0.013 1.03 ± 0.04 0.0218 ± 0.0007 0.61 ± 0.07 0.027 ± 0.001
NRC300 3.3 ± 0.1 0.017 ± 0.001 1.13 ± 0.12 196 ± 4 0.54 ± 0.02 1.65 ± 0.08 0.106 ± 0.003 0.083 ± 0.007 0.97 ± 0.04 0.0207 ± 0.0004 0.59 ± 0.05 0.027 ± 0.002
NRC301 3.4 ± 0.1 0.018 ± 0.002 1.17 ± 0.13 214 ± 7 0.59 ± 0.04 1.72 ± 0.14 0.107 ± 0.006 0.088 ± 0.011 0.99 ± 0.04 0.0209 ± 0.0005 0.57 ± 0.03 0.026 ± 0.001
NRC302 3.6 ± 0.2 0.018 ± 0.001 1.21 ± 0.11 206 ± 7 0.57 ± 0.04 1.79 ± 0.11 0.106 ± 0.007 0.069 ± 0.005 1.02 ± 0.01 0.0229 ± 0.0009 0.61 ± 0.01 0.027 ± 0.001
NRC400 3.1 ± 0.1 0.017 ± 0.001 1.29 ± 0.20 200 ± 4 0.53 ± 0.02 1.70 ± 0.15 0.116 ± 0.007 0.082 ± 0.014 1.02 ± 0.04 0.0214 ± 0.0007 0.53 ± 0.02 0.026 ± 0.001
NRC401 3.2 ± 0.2 0.019 ± 0.002 1.05 ± 0.04 190 ± 5 0.54 ± 0.05 1.53 ± 0.08 0.106 ± 0.008 0.074 ± 0.003 0.94 ± 0.03 0.0208 ± 0.0003 0.54 ± 0.03 0.027 ± 0.001
NRC402 3.2 ± 0.1 0.019 ± 0.003 1.33 ± 0.18 188 ± 6 0.51 ± 0.02 1.71 ± 0.11 0.116 ± 0.009 0.078 ± 0.009 0.94 ± 0.06 0.0203 ± 0.0002 0.57 ± 0.06 0.034 ± 0.004
NRC404 3.1 ± 0.2 0.019 ± 0.002 1.12 ± 0.09 196 ± 3 0.50 ± 0.01 1.60 ± 0.08 0.117 ± 0.012 0.079 ± 0.007 1.00 ± 0.06 0.0213 ± 0.0007 0.53 ± 0.02 0.031 ± 0.002
NRC405 3.2 ± 0.2 0.020 ± 0.002 1.11 ± 0.11 200 ± 5 0.51 ± 0.05 1.63 ± 0.07 0.118 ± 0.005 0.079 ± 0.006 0.99 ± 0.02 0.0208 ± 0.0006 0.59 ± 0.03 0.031 ± 0.001
NRC500 2.9 ± 0.1 0.018 ± 0.003 1.12 ± 0.03 196 ± 2 0.44 ± 0.03 1.35 ± 0.11 0.126 ± 0.008 0.073 ± 0.013 0.99 ± 0.05 0.0209 ± 0.0003 0.59 ± 0.03 0.032 ± 0.002
NRC501 2.8 ± 0.1 0.017 ± 0.002 1.34 ± 0.07 176 ± 3 0.47 ± 0.02 1.65 ± 0.07 0.121 ± 0.005 0.072 ± 0.007 0.97 ± 0.03 0.0206 ± 0.0004 0.54 ± 0.02 0.032 ± 0.003
NRC600 2.4 ± 0.1 0.014 ± 0.002 1.25 ± 0.08 180 ± 2 0.43 ± 0.03 1.58 ± 0.08 0.145 ± 0.005 0.067 ± 0.008 0.98 ± 0.06 0.0213 ± 0.0017 0.50 ± 0.01 0.031 ± 0.002
NRC601 2.7 ± 0.1 0.014 ± 0.001 1.14 ± 0.12 169 ± 6 0.41 ± 0.04 1.42 ± 0.11 0.143 ± 0.008 0.069 ± 0.010 0.95 ± 0.04 0.0203 ± 0.0014 0.45 ± 0.04 0.030 ± 0.002
NRC602 2.9 ± 0.1 0.016 ± 0.003 1.18 ± 0.12 209 ± 5 0.48 ± 0.04 1.54 ± 0.09 0.134 ± 0.008 0.064 ± 0.010 1.04 ± 0.07 0.0192 ± 0.0005 0.50 ± 0.01 0.031 ± 0.002
NRC700 2.2 ± 0.1 0.013 ± 0.001 1.17 ± 0.11 163 ± 5 0.36 ± 0.02 1.50 ± 0.10 0.168 ± 0.014 0.043 ± 0.008 1.08 ± 0.05 0.0181 ± 0.0005 0.43 ± 0.02 0.034 ± 0.003
NRC701 2.2 ± 0.1 0.013 ± 0.002 1.29 ± 0.10 171 ± 1 0.38 ± 0.01 1.64 ± 0.06 0.177 ± 0.009 0.048 ± 0.006 1.11 ± 0.05 0.0183 ± 0.0009 0.40 ± 0.01 0.036 ± 0.001
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Table 6. Mean results ± standard deviation for quintuplicate analyses of SPECTRUM cigarette filler tobacco for 11 inorganic analytes (µg/g

The results for 11 inorganic harmful and potentially harmful constituents of SPECTRUM cigarette tobacco filler showed that concentration ranges for beryllium, nickel, and arsenic in filler tobacco from SPECTRUM cigarettes (Table 6) were lower than the respective ranges of concentrations in filler tobacco previously reported for 50 varieties of cigarettes commercially available in the United States.15 Chromium, cobalt, and cadmium concentrations in SPECTRUM filler tobacco (Table 6) were below, or corresponded with the lower range of chromium, cobalt, and cadmium concentrations previously reported.15 Manganese and lead concentrations in SPECTRUM cigarette filler tobacco fell predominantly within the ranges of manganese and lead concentrations previously reported.15

DISCUSSION

Reference materials for analytical or clinical purposes are extremely useful to provide a consistent measurement process and to test various hypotheses. For example, when a measurement result for a reliable reference material is within the range specified for a specific property of the material, valid inferences may be made regarding the accuracy of measurements of that property when using the same method for measurements of uncharacterized samples with the same matrix. Reference materials may thus be utilized to infer that laboratories that can produce acceptable measurement results with a specific reference material are intercalibrated with other laboratories that have also been able to produce acceptable results.21,22 Since 1968, 17 Monitor quality control cigarettes, “reference” cigarettes and smokeless tobacco products have been produced and made available to researchers by CORESTA and the University of Kentucky for analytical chemistry and toxicology testing.23–25 In addition, 9 smokeless tobacco “reference” products are currently distributed by North Carolina State University.26 Manufacturers and related groups provide limited characterization of the design and chemistry of the quality control and reference products.24–29 These reference and monitor products are an invaluable resource to the research community engaged in analytical chemistry method development, chemical analysis of tobacco and tobacco smoke, and toxicological tobacco product research. However, tobacco reference products are produced from tobacco, an agricultural product, and, consequently, they are unlikely to be sufficiently characterized, stable, and homogenous in nature to meet the definition of a Standard Reference Material.21 However these products have a long history of use as quality control materials and have been analyzed and reported in the scientific literature alongside commercial products.27–29

Reference tobacco products are typically accompanied by a disclaimer that they are not for human consumption.25,26 Because of this restriction, researchers use commercial tobacco products in clinical studies requiring subjects to smoke tobacco cigarettes or use smokeless tobacco. Manufacturers can remove commercial tobacco products from the market place without notice and are not required to publicly disclose the chemical constituents in their products. Also, only a limited number of commercial products have been available to study cigarettes that differ substantially in nicotine content.30

Well characterized research cigarettes suitable for human consumption are an important tool in clinical studies such as those investigating the physiological impacts of cigarettes delivering various levels of nicotine, the combined impact of nicotine replacement and reduced nicotine cigarettes on nicotine addiction, and the relationship between nicotine dose and smoking behavior. In the work reported here we observe that most constituents, including the flavor compound menthol, are at or near the levels typically reported for commercial U.S. cigarette brands. Nicotine measurements confirm the targeted reduction of nicotine in the tobacco filler. Concentrations of other tobacco alkaloids were not likewise reduced. For example, while NNN and NNK were at the lower end of values reported for commercial products,18 overall concentrations of minor tobacco alkaloids that are precursors for formation of TSNAs in a burning cigarette,12,28 were higher than those found in commercial products. It has also been suggested that the minor tobacco alkaloids interact with the reinforcing properties of nicotine and thus may influence smoking behavior.32

The overall similarity in the chemistry and physical properties of SPECTRUM cigarettes to commercial cigarettes has potential implications for the acceptability and use behavior of study participants using the products. Baseline information on harmful and potentially harmful constituents in reference tobacco products, particularly constituent levels that fall outside typical ranges reported for commercial products, provide researchers with the opportunity to monitor smoking behavior and to identify biomarkers that will inform efforts to understand the role of nicotine in creating and sustaining addiction.

IMPLICATIONS FOR TOBACCO REGULATION

The large amount of analytical data on Harmful and Potentially Harmful Constituents (HPHCs) in the filler tobacco in SPECTRUM cigarettes presented here will supplement data on concentrations of already reported directly to the FDA center for Tobacco Products and in published manuscripts.14–17,28 In addition, the concentrations of nicotine and related alkaloids reported here will better enable researchers to interpret data in smoking topography and addiction studies. These data together with topography and addiction studies will better inform regulatory agencies when making decisions on regulatory levels for HPHCs and on the impact of reduced nicotine levels on potential for product addictiveness and cessation success.

Acknowledgments

This study was funded by internal funds of the U.S. Centers for Disease Control and Prevention. The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the U.S. Centers for Disease Control and Prevention.

Footnotes

Human Subjects Statement

No human subjects were involved in this study.

Conflict of Interest Statement

The authors affirm no conflicts of interest.

Contributor Information

Patricia Richter, Tobacco and Volatiles Branch, Centers for Disease Control and Prevention, Atlanta, GA.

Pappas R. Steven, Tobacco and Volatiles Branch, Centers for Disease Control and Prevention, Atlanta, GA.

Roberto Bravo, Tobacco and Volatiles Branch, Centers for Disease Control and Prevention, Atlanta, GA.

Joseph G. Lisko, Tobacco and Volatiles Branch, Centers for Disease Control and Prevention, Atlanta, GA.

Maria Damian, Battelle Analytical Services, Atlanta, GA.

Nathalie Gonzalez-Jimenez, Oak Ridge Institute for Science and Education, Oak Ridge, TN.

Naudia Gray, Tobacco and Volatiles Branch, Centers for Disease Control and Prevention, Atlanta, GA.

Lisa M. Keong, Battelle Analytical Services, Atlanta, GA.

Jacob B. Kimbrell, Oak Ridge Institute for Science and Education, Oak Ridge, TN.

Peter Kuklenyik, Centers for Disease Control and Prevention, Atlanta, GA.

Tameka S. Lawler, Tobacco and Volatiles Branch, Centers for Disease Control and Prevention, Atlanta, GA.

Grace E. Lee, Tobacco and Volatiles Branch, Centers for Disease Control and Prevention, Atlanta, GA.

Magaly Mendez, Tobacco and Volatiles Branch, Centers for Disease Control and Prevention, Atlanta, GA.

Jose Perez, Tobacco and Volatiles Branch, Centers for Disease Control and Prevention, Atlanta, GA.

Shakia Smith, Oak Ridge Institute for Science and Education, Oak Ridge, TN.

Hang Tran, Tobacco and Volatiles Branch, Centers for Disease Control and Prevention, Atlanta, GA.

Robert Tyx, Tobacco and Volatiles Branch, Centers for Disease Control and Prevention, Atlanta, GA.

Clifford H. Watson, Tobacco and Volatiles Branch, Centers for Disease Control and Prevention, Atlanta, GA.

References

  • 1.Twenty Second Century. SPECTRUM Government Research Cigarettes. [Accessed May 11, 2015]; Available at: http://www.xxiicentury.com/
  • 2.National Institute on Drug Abuse (NIDA) Nicotine Research Cigarettes Drug Supply Program. [Accessed May 11, 2015]; Available at: http://www.drugabuse.gov/
  • 3.Hatsukami DK, Heishman SJ, Vogel RI, et al. Dose-response effects of spectrum research cigarettes. Nicotine Tob Res. 2013;15(6):1113–1121. doi: 10.1093/ntr/nts247. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 4.Food and Drug Administration (FDA) Tobacco Products. Science and Research. [Accessed May 11, 2015]; Available at: http://www.fda.gov/TobaccoProducts/PublicHealthScienceResearch/default.htm.
  • 5.National Institutes of Health (NIH) Tobacco Regulatory Science Program (TRSP) [Accessed May 11, 2015]; Available at: https://prevention.nih.gov/tobacco-regulatory-science-program.
  • 6.Kozlowski LT, O’Connor RJ. Cigarette filter ventilation is a defective design because of misleading taste, bigger puffs, and blocked vents. Tob Control. 2002;11(Suppl I):i40–i50. doi: 10.1136/tc.11.suppl_1.i40. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 7.Belluzzi JD, Wang R, Leslie FM. Acetaldehyde enhances acquisition of nicotine self-administration in adolescent rats. Neuropsychopharmacol. 2005;30(4):705–712. doi: 10.1038/sj.npp.1300586. [DOI] [PubMed] [Google Scholar]
  • 8.Taylor JK. Quality Assurance of Chemical Measurements. Boca Raton: CRC Press; 1987. pp. 79–81. [Google Scholar]
  • 9.Caudill SP, Schleicher RL, Pirkle JL. Multi-rule quality control for the age-related eye disease study. Stat Med. 2008;27:4094–4106. doi: 10.1002/sim.3222. [DOI] [PubMed] [Google Scholar]
  • 10.Ai J, Taylor KM, Lisko JG, et al. Menthol content in U.S. marketed cigarettes. Anal Meth. 2015 doi: 10.1093/ntr/ntv162. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 11.Wu W, Zhang L, Jain RB, et al. Determination of carcinogenic tobacco-specific nitrosamines in mainstream smoke from U.S.-brand and non-U.S.-brand cigarettes from 14 countries. Nicotine Tob Res. 2005;7:443–451. doi: 10.1080/14622200500125898. [DOI] [PubMed] [Google Scholar]
  • 12.Lisko JG, Stanfill SB, Duncan BW, Watson CH. Application of GC-MS/MS for the analysis of tobacco alkaloids in cigarette filler and various tobacco species. Anal Chem. 2013;85:3380–3384. doi: 10.1021/ac400077e. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 13.Stanfill SB, Jia LT, Ashley DL, Watson CH. Rapid and chemically selective nicotine quantification in smokeless tobacco products using GC-MS. J Chrom Sci. 2009;47:902–909. doi: 10.1093/chromsci/47.10.902. [DOI] [PubMed] [Google Scholar]
  • 14.Pappas RS, Martone N, Gonzalez-Jimenez N, et al. Determination of Toxic Metals in Little Cigar Tobacco with ‘Triple Quad’ ICP-MS. J Anal Toxicol. 2015;39:347–352. doi: 10.1093/jat/bkv016. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 15.Fresquez MR, Pappas RS, Watson CH. Establishment of Toxic Metal Reference Range in Tobacco from U.S. Cigarettes. J Anal Toxicol. 2013;37:298–304. doi: 10.1093/jat/bkt021. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 16.Fresquez MR, Gonzalez-Jimenez N, Gray N, et al. High Throughput Determination of Mercury in Tobacco and Mainstream Smoke from Little Cigars. J Anal Toxicol. 2015;39:545–550. doi: 10.1093/jat/bkv069. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 17.Ai J, Taylor KM, Lisko JG, et al. Menthol Content in US Marketed Cigarettes. Abstracts of Papers, Society for Research on Nicotine and Tobacco Annual Meeting; Philadelphia. 2015. p. 188. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 18.Stepanov I, Knezevich A, Zhang L, et al. Carcinogenic tobacco-specific N-nitrosamines in US cigarettes: Three decades of remarkable neglect by the tobacco industry. Tob Control. 2015;21:44–48. doi: 10.1136/tc.2010.042192. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 19.Wu W, Ashley DL, Watson CH. Determination of nicotine and other minor alkaloids in international cigarettes by solid-phase microextraction and gas chromatography/mass spectrometry. Anal Chem. 2015;74:4878–4884. doi: 10.1021/ac020291p. [DOI] [PubMed] [Google Scholar]
  • 20.Counts ME, Hsu FS, Tewes FJ. Development of a commercial cigarette “market map” comparison methodology for evaluating new or non-conventional cigarettes. Regul Toxicol Pharmacol. 2006;46:225–242. doi: 10.1016/j.yrtph.2006.07.002. [DOI] [PubMed] [Google Scholar]
  • 21.Taylor JK. Quality Assurance of Chemical Measurements. New York, NY: CRC Press; 1987. p. 160. [Google Scholar]
  • 22.Uriano GA, Gravatt CC. The role of reference materials and reference methods in chemical analysis. Crit Rev Anal Chem. 1977;6:361–411. [Google Scholar]
  • 23.Anonymous. Reference products used in tobacco and smoke analyses. Tob J Int. 2013:150. [Google Scholar]
  • 24.Cooperation Centre for Scientific Research Relative to Tobacco (CORESTA) Reference Products. [Accessed May 11, 2015]; Available at: http://www.coresta.org/ [Google Scholar]
  • 25.University of Kentucky. College of Agriculture. Reference Cigarette Program. [Accessed May 8, 2015]; Available at: http://www2.ca.uky.edu/refcig/ [Google Scholar]
  • 26.North Carolina State University. Department of Crop Science. Smokeless Tobacco Reference Products. [Accessed May 11, 2015]; Available at: http://www.tobacco.ncsu.edu/strp.html. [Google Scholar]
  • 27.Chepiga TA, Morton MJ, Murphy PA, et al. A comparison of the mainstream smoke chemistry and mutagenicity of a representative sample of the US cigarette market with two Kentucky reference cigarettes (K1R4F and K1R5F) Food Chem Toxicol. 2000;10:949–962. doi: 10.1016/s0278-6915(00)00086-7. [DOI] [PubMed] [Google Scholar]
  • 28.Oldham MJ, DeSoi DJ, Rimmer LT, et al. Insights from analysis for harmful and potentially harmful constituents (HPHCs) in tobacco products. Regul Toxicol Pharmacol. 2014;70(1):138–148. doi: 10.1016/j.yrtph.2014.06.017. (2014) [DOI] [PubMed] [Google Scholar]
  • 29.Roemer E, Ottmueller TH, Zenzen V, et al. Cytotoxicity, mutagenicity, and tumorigenicity of mainstream smoke from three reference cigarettes machine-smoked to the same yields of total particulate matter per cigarette. Food Chem Toxicol. 2009;47(8):1810–1818. doi: 10.1016/j.fct.2009.04.048. [DOI] [PubMed] [Google Scholar]
  • 30.Hammond D, O’Connor RJ. Reduced nicotine cigarettes: Smoking behavior and biomarkers of exposure among smokers not intending to quit. Cancer Epidemiol Biomarkers Prev. 2014;23(10):2032–2040. doi: 10.1158/1055-9965.EPI-13-0957. [DOI] [PubMed] [Google Scholar]
  • 31.Moldoveanu SC, Borgerding M. Formation of tobacco specific nitrosamines in mainstream cigarette smoke, Part 1, FTC smoking. Beitr Tabakforsch. 2008;23(1):19–31. [Google Scholar]
  • 32.Clemens KJ, Caillé S, Stinus L, Cador M. The addition of five minor tobacco alkaloids increases nicotine-induced hyperactivity, sensitization and intravenous self-administration in rats. Int J Neuropsychopharmacol. 2009;12(10):1355–1366. doi: 10.1017/S1461145709000273. [DOI] [PubMed] [Google Scholar]

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