Qualitative determination of volatile substances in different flavored cigarette paper by using headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) combined with chemometrics.

In order to investigate the difference of volatile substances among flavored cigarette paper, which are supplied by several manufacturers with different batches, the stability of the complex system of scented cigarette paper was analyzed and evaluated. In this study, Headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) was used to detect the aroma compounds of 23 flavored cigarette paper samples. Based on fingerprint analysis, the differences and changes of aroma compounds of different samples were studied in the form of data visualization. Principal component analysis, partial least squares regression analysis, cluster heatmap analysis and artificial neural network analysis were used to evaluate the stability of different cigarette paper. The results show that: A total of 29 volatile substances were identified from different scented cigarette paper. Fingerprint analysis revealed that the volatile substances of different cigarette paper samples were roughly the same, but not the content. The results of chemometrics analysis showed that there were significant differences in the characteristic aroma compounds of cigarette paper from different manufacturers. HS-GC-IMS technology combined with chemometrics method could be applied to determine the difference of volatile substances among different flavored cigarette paper, which theoretically and technically supported the quality stability maintenance and identification of flavored cigarette paper processed in different places.

Determination and Difference Analysis of Phenolic Compounds in Smokers' Saliva and Mainstream Smoke.

To study the differences in phenolic compounds between tobacco smokers' saliva and mainstream smoke, a method was developed for the analysis of 12 phenolic compounds in saliva and mainstream smoke based on ultrahigh-performance liquid chromatography with fluorescence detection (UPLC-FLD). The contents and distributions of phenolic compounds in tobacco smokers' saliva and mainstream smoke were compared. The results were as follows: (1) Phenolic compounds were quantitatively analyzed by the internal standard method using 4-fluorophenol as an internal standard. For smokers' saliva samples, the limits of quantification (LOQs) ranged from 2.2 to 19.1 µg/L, and the recoveries were from 80.2% to 119.2% at the three spiked levels. For mainstream smoke samples, the LOQs ranged from 0.03 to 0.26 µg/cig, and the recoveries ranged from 84.9% to 107.0% at the three spiked levels. (2) The contents of phenolic compounds from 14 cigarettes in mainstream smoke and smokers' saliva were determined. In mainstream smoking, the main phenolic compounds were hydroquinone, catechol, phenol, meta- and para-Cresol, and o-methylhydroquinone. In smokers' saliva, the main phenolic compounds were phenol and meta- and para-Cresol and the contents of phenolic compounds in smokers' saliva from different cigarettes were significantly different. (3) The content distribution patterns of phenolic compounds in smokers' saliva differed from those in mainstream smoke. The predominant phenolic compound in mainstream smoke was dihydroxybenzene, while monophenols predominated in smokers' saliva. (4) The contents of phenolic compounds from five kinds of cigarettes were analyzed in the saliva of different smokers using principal component analysis, which indicated that cigarettes with different sensory effects were clearly distinguished by differences in the contents of phenolic compounds in saliva.

Multivariate quantitative analysis of quality trend based on non-volatile characteristic components in different Panax notoginseng samples using HPLC.

In order to identify real and fake Panax notoginseng samples, the high performance liquid chromatography (HPLC) was used to analyze P. notoginseng samples of non-volatile characteristic components in P. notoginseng powder samples with 10 %, 30 %, 50 % ratio, combined with principal component analysis - mahalanobis distance (PCA-MD). The results showed that: (1) The PCA analysis showed that mahalanobis with different stem and leaf powder were divided into four categories, and the gravity center of the pattern (classification) showed that the long axis of the trend chart gradually increased with the increase of the proportion of the stem and leaf powder, and the trend chart was gradually away from the control group; (2) The mahalanobis distance indicated that the range of mahalanobis distance fluctuation (upper limit) of several P. notoginseng powder samples is 395.03∼48252.70. The larger the percentage of the stem and leaf powder in P. notoginseng samples, it is farther away from the normal P. notoginseng samples. It indicated that the product of P. notoginseng samples can be evaluated with the mahalanobis distance. The results of this study can be applied to identification and homogenization evaluation of P. notoginseng between real and fake samples.

Simultaneous determination of six alkaloids in tobacco and tobacco products by direct analysis of real-time triple quadrupole mass spectrometry with a modified pretreatment method.

In order to determine six alkaloids (mass fraction) of nicotine, nornicotine, myosmine, anatabine, anabasine, and nicotyrine in tobacco and tobacco products quickly, accurately, and simultaneously, a novel method based on direct analysis of real-time model in situ ionization technique combined tandem mass spectrometry with a modified sample pretreatment was established, in which experimental parameters such as the type and amount of extraction solvent and injection rate were optimized, respectively. The samples of five commercial cigarettes and five kinds of tobacco leaves were analyzed by the established method, and the determined values were compared with those obtained using a gas chromatography with mass spectrometry method: (1) Under optimized conditions (30 mL ultrapure water as extraction solvent and with extraction rate of 0.6 mm/s), analysis could be completed within 10 min. (2) The linear range of the method was 0.002-2000 µg/g with R 2 = 0.9957 , the recovery ranged from 86.8 to 105.6%, and the limit of detection and the limit of quantification were 0.004-0.835 µg/g and 0.013-2.787 µg/g, respectively. (3) The relative standard deviation between direct analysis of real-time method and the gas chromatography with mass spectrometry method was 0.34-8.83%. The established method is rapid, reliable, and suitable for the ultrafast determination of six alkaloids in tobacco and tobacco products.

Three new isoflavones from the Pueraria montana var. lobata (Willd.) and their bioactivities.

Three new isoflavones, 7-acetyl-4',6-dimethoxy-isoflavone (1), 7-acetyl-4'-hydroxy-6-methoxy-isoflavone (2) and 7-acetyl-6,8-dimethoxy-4'-hydroxy-isoflavone (3), together with five known flavones (4-8), were isolated from the Pueraria montana var. lobata (Willd.). Their structures were elucidated by spectroscopic methods, including extensive 1D- and 2D NMR techniques. Compounds 1-8 were evaluated for their anti-tobacco mosaic virus (anti-TMV) activities. The results showed that compounds 1 and 2 exhibited high anti-TMV activities with inhibition rates of 36.8 and 33.6%, respectively. The inhibition rates are higher than that of positive control. The other compounds also showed potential anti-TMV activities with inhibition rates in the range of 21.8~28.4%, respectively. The cytotoxicities of compounds 1-3 against five human tumour cell lines (NB4, A549, SHSY5Y, PC3 and MCF7) were also tested. The results revealed that compounds 1-3 showed weak inhibitory activities against some tested human tumour cell lines with IC50 values in the range of 1.2-3.6 µM.