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Li Z.,China National Tobacco Quality Supervision & Test Center | Tang G.,China National Tobacco Quality Supervision & Test Center | Hu Q.,China National Tobacco Quality Supervision & Test Center
Tobacco Science and Technology | Year: 2016

In order to study the influences of two smoking regimes [ISO and Health Canadian Intense (HCI) smoking regimes] on the precision of specific measurements and results of mainstream cigarette smoke, a series of collaborative studies were carried out using seventeen smoke analyte indices including, puff number, total particulate matter, tar, nicotine, carbon monoxide(CO); N-nitrosonornicotine (NNN), 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone(NNK); benzo[a] pyrene (B[a]P); formaldehyde, acetaldehyde, acrolein, crotonaldehyde; phenol; hydrogen cyanide (HCN); ammonia; 1,3-butadiene, benzene. The results were statistically analyzed, the repeatability (r) and reproducibility (R) of nine methods at six delivery levels (m) were obtained according to GB/T 6379.2-2004/ISO 5725-2: 1994 recommendations, and the linear regressions of m with r and R for each analyte were determined. The results showed that: the relative repeatability (r%) and relative reproducibility (R%) for tar, nicotine, CO were about 10% and 20%, respectively, while those for the other analytes were between 20% and 45%. The precision for tar, nicotine, CO under both repeatability and reproducibility conditions were clearly better than that for the other analytes. In addition, no significant improvements for measurement precisions were found under HCI smoking regime even though the analytes' yields were much higher than those under ISO regime. In contrast to the samples smoked under ISO regime, a much weaker correlations of linearity between m and r or R were obvious for most of the analytes under HCI regime. Meanwhile for some analytes, the measurement differences between the two type (rotary and linear) smoking machines were higher under HCI regime. Following the existing mainstream cigarette smoke collection, the stability of smoking machine's puffing parameters, such as puff number, were lower under HCI regime. These results indicated that the typical smoking machines are not optimised for the robust analysis of mainstream cigarette smoke under HCI smoking regime. © 2016, Editorial Office of Tobacco Science and Technology. All right reserved.


Liu L.,China National Tobacco Quality Supervision & Test Center | Li X.,China National Tobacco Quality Supervision & Test Center | Chen H.,China National Tobacco Quality Supervision & Test Center | Hou H.,China National Tobacco Quality Supervision & Test Center | Hu Q.,China National Tobacco Quality Supervision & Test Center
Tobacco Science and Technology | Year: 2016

In order to evaluate toxicity of crotonaldehyde in cigarette smoke, calf thymus DNA damage caused by crotonaldehyde exposure was investigated at different concentrations of crotonaldehyde. After exposure, calf thymus DNA samples were firstly hydrolyzed by enzymes, then purified by solid phase extraction (SPE), concentrated and re-dissolved subsequently. Finally, the DNA adducts of S-α-CH3-γ-OH-1, N2-propanodeoxyguanosine (CdG-1) and R-α-CH3-γ-OH-1, N2-propano-deoxyguanosine (CdG-2) induced by crotonaldehyde exposure were determined by high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). The relationships between CdG adducts and crotonaldehyde exposure dose were established. The results indicated that: 1) Good separation efficiency and short analysis time were achieved by using a C18 column under gradient elution conditions. 2) The calibration curves presented good linearity (R2>0.999) with the detection limits of CdG-1 and CdG-2 at 0.006 and 0.005 ng/mL, respectively. The recoveries ranged from 83.3% to 101.0% with the relative standard deviations (RSDs) less than 7.0%. 3) The content of CdG adducts in calf thymus DNA increased with the increase of crotonaldehyde exposure dose, namely, dose-response relationship between them. The developed method is simple and accurate, thus can be used as an effective tool for evaluating the DNA damage caused by crotonaldehyde exposure. © 2016, Editorial Office of Tobacco Science & Technology. All right reserved.


Luo Y.,China National Tobacco Quality Supervision & Test Center | Li X.,China National Tobacco Quality Supervision & Test Center | Zhu F.,China National Tobacco Quality Supervision & Test Center | Zhang H.,China National Tobacco Quality Supervision & Test Center | And 2 more authors.
Tobacco Science and Technology | Year: 2016

In order to analyze the pesticide residues in tobacco leaves, tobacco extract was directly analyzed by on-line gel permeation chromatography-gas chromatography-tandem mass spectrometry. This method was able to quantify the residue levels of 31 pesticides, and the optimal determination conditions were obtained via optimizing gel permeation chromatography collection time and multiple reaction monitoring parameters, which could influence the determination results. The results showed that: 1)Under the optimized conditions, the limits of detection of the method for the target analytes ranged from 1.95 to 212 ng/L, the determination coefficients (R2)were more than 0.99 for all the target analytes, the intra- and inter-day relative standard deviations were no more than 6.3% and 10.2%, respectively; and the recoveries of standard were from 82.2% to 121.5% for test samples. 2)The method was successfully applied to the analysis of pesticide residues in tobacco samples, the test results well agreed with those of existing standard methods. © 2016, Editorial Office of Tobacco Science & Technology. All right reserved.


Ou H.,China National Tobacco Quality Supervision & Test Center
Se pu = Chinese journal of chromatography / Zhongguo hua xue hui | Year: 2010

N-nitrosonornicotine (NNN), 4-( methylnitrosamino )-1-(3-pyridyl )-1-butanone (NNK), N-nitrosoanatabine (NAT) and N-nitrosoanabasine (NAB) are the most abundant carcinogens identified in tobacco and tobacco smoke. The accurate quantifications of NNN, NNK, NAT and NAB are necessary to evaluate its impact on the public health. A liquid chromatography-electrospray tandem mass spectrometry (LC-ESI MS/MS) method was developed to simultaneously determine NNN, NNK, NAT and NAB in mainstream cigarette smoke. Mainstream smoke was collected in a Cambridge filter pad and then was extracted by 10 mL 100 mmol/L ammonium acetate after 100 microL of mixed deuterated internal standards was added. Then the extract was detected by using positive electrospray ionization on a tandem mass spectrometer in multiple reaction monitoring (MRM) mode. NNN, NNK, NAT and NAB were separated on a Zorbax Eclipse XDB-C18 column with the gradient elution using mobile phase A (0.1% acetic acid in water) and mobile phase B (0.1% acetic acid in methanol). The detection limits for NNN, NNK, NAT and NAB were 0.019, 0.002, 0.008 and 0.007 microg/L, respectively. The recoveries were varied from 84.9% to 104.5% for Chinese Virginia cigarettes and the relative standard deviations (n = 8) ranged from 2.96% to 6.65%. This proposed approach, which provides a higher sensitivity and specificity, is suitable for the determination of NNN, NNK, NAT and NAB in mainstream cigarette smoke.


Liu Y.,China National Tobacco Quality Supervision & Test Center | Hu J.,CAS Zhengzhou Research Institute | Liu F.,CAS Zhengzhou Research Institute | Zhao M.,CAS Zhengzhou Research Institute | And 2 more authors.
Tobacco Science and Technology | Year: 2015

In order to quantitatively characterize the micro-porous structure of different kind tobacco leaves, the specific surface area and porosity of flue-cured, burley and oriental tobacco leaves were measured by N2-adsorption-desorption-method followed the pretreatment of immersing in ethanol. Meantime, the surface morphology of tobacco samples was observed by a scanning electron microscope (SEM). The results showed that: all the samples possessed obvious characters of porous medium, i.e. larger specific surface area and smaller pore volume; the porosity of oriental tobacco sample was 2.60%, that of flue-cured and burley tobacco samples was 4.78% and 10.73%, respectively; with a higher proportion of pore in leaf, burley tobacco leaf was open in structure; while oriental leaf was relatively close, and flue-cured tobacco leaf was in-between. The pore distribution characters and pore volume of samples agreed with the observation by scanning electron microscope. ©, 2015, Editorial Office of Tobacco Science and Technology. All right reserved.


Pang Y.,China National Tobacco Quality Supervision & Test Center | Jiang X.,China National Tobacco Quality Supervision & Test Center | Luo Y.,China National Tobacco Quality Supervision & Test Center | Li X.,China National Tobacco Quality Supervision & Test Center | And 2 more authors.
Tobacco Science and Technology | Year: 2015

In order to investigate the puff-by-puff release characteristics of mainstream cigarette smoke, a photo-ionization-time-of-flight mass spectrometry (PI-TOF/MS) method was developed for on-line analyzing seven organic compounds (acetaldehyde, 1, 3-butadiene, acetone, isoprene, 2-butanone, benzene and toluene) in mainstream cigarette smoke. The constant volume sampling of mainstream cigarette smoke was achieved by a constant flow orifice, the smoke was directly introduced into the ion source of PI-TOF/MS through a sampling tube with a heating unit. The results showed that: 1) The intra-day and inter-day repeatabilities were good with the relative standard deviations (RSDs) less than 15%, exclusive of the first and the last puffs, where the deviations were larger due to cigarette lighting and variable puff volume, respectively. 2) The RSDs between the results of 1R5F and 3R4F reference cigarettes determined by this method and the mean test values of CORESTA collaborative experiments were less than 10%. 3) The deliveries of different compounds in single puff differed obviously, as did the deliveries between different puffs. This method is simple, fast, accurate, and suitable for the on-line puff-by-puff analysis of mainstream cigarette smoke. ©, 2015, Editorial Office of Tobacco Science and Technology. All right reserved.


Bian Z.,China National Tobacco Quality Supervision & Test Center | Liu S.,China National Tobacco Quality Supervision & Test Center | Yang F.,China National Tobacco Quality Supervision & Test Center | Li Z.,China National Tobacco Quality Supervision & Test Center | And 2 more authors.
Tobacco Science and Technology | Year: 2015

In order to determine the acidity of triacetin efficiently, a rapid titration method was developed with electric continuous liquid divider, and the acidity of 10 domestic and imported triacetin samples was determined. The results showed that: 1) The optimized procedure was as follows: triacetin sample was diluted by anhydrous ethanol, phenolphthalein was added as an indicator, then 0.11 mL of 0.02 mol/L NaOH solution was added quickly by an electric continuous liquid divider at the rate of 0.11 mL every dose repeatedly until solution's color turned pink, the total dose number of NaOH solution addition could be directly translated into triacetin acidity by a conversion table. 2) The recoveries of the method ranged from 99.3% to 99.6% with the relative standard deviations (RSDs) less than 7%. 3) Among the 10 tested samples, the acidity of 7 samples was below the restrictive value of 0.010%, and that of 3 samples was above the value, in which the acidity of 2 samples was more than 0.020%. This method is simple, fast, accurate, and suitable for determining the acidity of triacetin for cigarette. ©, 2015, Editorial Office of Tobacco Science and Technology. All right reserved.


PubMed | CAS Hefei Institutes of Physical Science and China National Tobacco Quality Supervision & Test Center
Type: | Journal: Journal of chromatography. B, Analytical technologies in the biomedical and life sciences | Year: 2015

1,3-Butadiene (BD) is a ubiquitous environmental pollutant found in tobacco smoke. In vivo, BD is mainly metabolized to form monohydroxybutenylmercapturic acid (MHBMA) and N-acetyl-S-(3, 4-dihydroxybutyl) cysteine (DHBMA). The accurate quantification of MHBMA and DHBMA in urine may provide important insights into the actual internal exposure of the general population to BD. 8-Hydroxy-2-deoxyguanosine (8-OHdG) is the biomarker of oxidative damage. In this study, a column-switching LC-MS/MS method was developed and validated for the simultaneous quantification of MHBMA, DHBMA derived from BD exposure and 8-OHdG in human urine. Urine samples were loaded on a LiChrospher() RP-8 ADS (25m) 254mm RAM column for the extraction and clean-up of analytes. The separation was achieved using a SUPELCO() LC-18-DB column (75mm3.0mm, 3m). The analytes were ionized in negative electrospray ionization mode and analyzed in multiple reaction monitoring mode. Under optimum conditions, recoveries ranged from 78.9% to 101.7%, with relative standard deviations less than 11%. The limits of quantification ranged from 0.15 to 0.27ng/mL, highlighting the high sensitivity of this simple method. The validated method was successfully applied to analysis urine samples from 56 non-smokers and 233 smokers who smoked cigarettes with 3 different tar yields. There was a correlation between urinary MHBMA, DHBMA and 8-OHdG. This method did not require any preparation process and efficiently removed interference from the matrix by using column-switching. The developed method is applicable to epidemiological studies.


PubMed | CAS Hefei Institutes of Physical Science and China National Tobacco Quality Supervision & Test Center
Type: | Journal: Journal of separation science | Year: 2015

A stable isotope dilution liquid chromatography with tandem mass spectrometry method for the analysis of 16 polycyclic aromatic hydrocarbons in cigarette smoke condensate was developed and validated. Compared with previously reported methods, this method has lower limits of detection (0.04-1.35 ng/cig). Additionally, the proposed method saves time, reduces the number of separation steps, and reduces the quantity of solvent needed. The new method was applied to evaluate polycyclic aromatic hydrocarbon content in 213 commercially available cigarettes in China, under the International Standardization Organization smoking regime and the Health Canadian intense smoking regime. The results showed that the total polycyclic aromatic hydrocarbon content was more than two times higher in samples from the Health Canadian intense smoking regime than in samples from the International Standardization Organization smoking regime (1189.23 vs. 2859.50 ng/cig, p<0.05). Meanwhile, the concentration of individual polycyclic aromatic hydrocarbons (and total polycyclic aromatic hydrocarbons) increased with labeled tar content in both of the tested smoking regimes. There was a positive correlation between total polycyclic aromatic hydrocarbons under the International Standardization Organization smoking regime with that under the Health Canadian intense smoking regime. The proposed liquid chromatography with tandem mass spectrometry method is satisfactory for the rapid, sensitive, and accurately quantitative evaluation of polycyclic aromatic hydrocarbon content in cigarette smoke condensate, and it can be applied to assess potential health risks from smoking. This article is protected by copyright. All rights reserved.


PubMed | Sichuan Tobacco Quality Supervision and Testing Station and China National Tobacco Quality Supervision & Test Center
Type: Journal Article | Journal: Journal of chromatographic science | Year: 2014

A method for the determination of three acidic herbicides, dicamba, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) in tobacco and soil has been developed based on the use of liquid-liquid extraction and dispersive solid-phase extraction (dispersive-SPE) followed by UPLC-MS/MS. Two percentage of (v/v) formic acid in acetonitrile as the extraction helped partitioning of analytes into the acetonitrile phase. The extract was then cleaned up by dispersive-SPE using primary secondary amine as selective sorbents. Quantitative analysis was done in the multiple-reaction monitoring mode using stable isotope-labeled internal standards for each compound. A separate internal standard for each analyte is required to minimize sample matrix effects on each analyte, which can lead to poor analyte recoveries and decreases in method accuracy and precision. The total analysis time was <4 min. The linear range of the method was from 1 to 100 ng mL(-1) with a limit of detection of each herbicide varied from 0.012 to 0.126 ng g(-1). The proposed method is faster, more sensitive and selective than the traditional methods and more accurate and robust than the published LC-MS/MS methods.

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