Background: Speciation analysis is defined as the analytical activities of identifying and/or measuring the quantities of one or more individual chemical species in a sample. The knowledge of elemental species provides more complete information about mobility, bioavailability and the impact of elements on ecological systems or biological organisms. It is no longer sufficient to quantitate the total elemental content of samples to define toxicity or essentiality. Thus speciation analysis is of vital importance and generally offers a better understanding of a specific element. Discussion: Thorough speciation scheme consisting of sampling, sample preparation, species analysis and evaluation were described. Special emphasis is placed on recent speciation analysis approaches including both direct and coupling methods. A current summary of advantages and limitations of the various methods as well as an illustrative method comparison are presented. Certain elements and species of interest are briefly mentioned and practical examples of speciation applications in tobacco and other important economic crops are also discussed. Aim/Conclusion: This review aims to offer comprehensive knowledge about elemental speciation and provide readers with valuable information. Many strategies have been developed for the determination of multiple elemental species in tobacco and other important economic crops. Nevertheless, it is an eternal pursuit to establish speciation methods which can balance accuracy, agility as well as universality.

The determination of mixing ratio and the evaluation of cut tobacco uniformity in cigarettes are vital to tobacco manufacturing. Herein, an intelligent and fast method was developed for the evaluation of stem uniformity in cigarettes using near-infrared (NIR) spectroscopy according to the spectral difference between tobacco leaves and stems. Tobacco samples with different stem ratios were prepared precisely and then measured by NIR. Partial least squares (PLS) prediction model was established to bring out the accurate and rapid determination of stem ratio in a tobacco blend. The relative error of stem ratios was within 3.88% for external prediction. It is worth mentioning that this model can realize the quantitative evaluation of the uniformity for cut stems in a "single" cigarette, providing a brand-new technique for the quality assurance of cigarettes in the market as well as an extended potential in the uniformity evaluation of agricultural products with similar type and quality.

建立了高效液相色谱-电感耦合等离子体质谱法(HPLC-ICP-MS)测定烟草及其制品中无机铅[Pb(Ⅱ)]、三甲基铅(TML)和三乙基铅(TEL)含量的方法.将烟草样品粉碎后,加入体积比为60∶40的1 mmol·L-1 1-戊烷磺酸钠溶液和甲醇的混合溶液(流动相)15 mL,于40℃超声萃取20 min,离心,上清液过0.22 μm滤膜,用HPLC-ICP-MS测定滤液中3种铅形态含量.在烟草样品中加入硝酸和30％过氧化氢溶液,在程序升温条件下微波消解,消解液用水稀释后,用ICP-MS测定其中的铅总量.在HPLC分析中,在1.0 mL·min-1流量下用流动相等度洗脱吸附在ZORBAX Eclipse Plus C18反相色谱柱上的3种铅形态,8 min即可实现高效分离.在ICP-MS分析中,同步监测206Pb、207Pb和208Pb等3种铅同位素,用三者含量和进行定量.结果显示:3种铅形态的质量浓度在0.5～50.0 μg·L-1内与其对应的质谱响应值呈线性关系,检出限(3S/N)为0.33～0.47 μg·L-1;对实际样品进行3个浓度水平的加标回收试验,所得回收率为81.9％～96.5％,测定值的相对标准偏差(n = 6)为5.3％～9.6％.方法用于烟叶样品和卷烟成品的分析,结果显示:烟叶样品及卷烟成品中均未检出有机铅,其铅形态以Pb(Ⅱ)为主,且含量较低(1.53～5.08 μg·g-1);下、中、上部烟叶中铅含量呈递减分布;卷烟成品中的铅含量与烟叶样品的基本处于相同水平;检出的3种铅形态含量总和占铅总量的74.3％～84.6％.

To study the influences of four flavoring methods (cut tobacco, breakable capsule, tow, and cotton thread flavoring) on the transfer of aroma components in slim cigarette smoke, a gas chromatography-tandem mass spectrometry (GC-MS/MS) method for simultaneously and quantitatively determining the alcohols, aldehydes, ketones and esters in cut tobacco, particulate matter of mainstream smoke, and filter were developed. The results showed that:1) After storing airtightly for 30 days, the distribution of aroma components in cut tobacco and filter differed significantly among the cigarettes flavored by the four methods. The transfer rates of aroma components were the highest in tobacco-flavored samples. 2) The transfer rates of aroma components to particulate matter of mainstream smoke in tow-flavored samples were similar to those in thread-flavored samples. The transfer rates of aroma components with higher boiling points were the highest in tobacco-flavored samples and the lowest in capsule-flavored samples. 3) With the increase of boiling points of congeneric aroma components, the transfer rates of aldehydes, ketones and esters aroma components to particulate matter of mainstream smoke in tobacco-flavored, tow-flavored and thread-flavored samples increased, while those in capsule-flavored samples increased first and then decreased. The alcoholic aroma components slightly differed from the other aroma components in the relationships between the transfer rate to particulate matter of mainstream smoke and boiling point. 4) The filter retention rates of the four kind aroma components in tow-flavored samples were slightly higher than those in thread-flavored samples. Capsule flavoring resulted in the highest filter retention rates of aroma components with higher boiling points, while tobacco flavoring was the opposite.

建立了气相色谱-串联质谱法(GC-MS/MS)同时测定烟草中15种有机酸的分析方法.样品采用微波辅助法进行甲酯化反应,采用二氯甲烷进行液液分配,GC-MS/MS多反应监测(MRM)模式进行测定,内标法定量.15种有机酸检出限为0.08～0.52 μg/mL,不同添加水平的加标回收率为81.2％～107.3％,方法可用于烟草中有机酸含量的检测.采用该方法对不同类别烟草制品中有机酸含量分布进行了分析,同时对制丝过程关键工序下有机酸含量变化规律进行了探究,为卷烟质量控制和工艺技术优化提供了技术支持.

[目的]了解不同品牌卷烟产品之间的挥发性有机物差异,分析不同品牌卷烟产品风格特征和品质差异.[方法]选取5款市售品牌卷烟,基于顶空气相色谱—离子迁移谱(HS-GC-IMS)开展挥发性有机物研究,建立指纹图谱分析不同挥发性有机物含量分布,采用主成分分析法研究不同品牌卷烟产品之间的相似度.[结果]指纹图谱结果表明:5款卷烟样品的挥发性有机物组分大致相同,但不同化合物含量存在一定差异;主成分分析结果表明:当卷烟中挥发性有机物的主成分贡献度达到68％时,可通过指纹图谱的特征成分区分不同品牌的卷烟.[结论]借助HS-GC-IMS技术可以分析不同品牌卷烟之间挥发性物质的差异,并以此区分不同品牌卷烟,为不同品牌卷烟的风格分析和品质评定提供一定的理论依据和技术支持.

采用液相色谱-串联质谱(LC-MS/MS)法快速测定了烤烟中11种Amadori化合物,并结合主成分分析(PCA)、层次聚类热力图分析(HCHMA)及t分布随机邻域嵌入(t-SNE)等多元统计分析方法,研究Amadori化合物与烤烟香型的关系.结果表明:①目标化合物的线性关系良好(r>0.995);检出限(LODs)为1.0～10.0 ng/mL;日内和日间精密度(RSDs)分别为1.1％～4.8％和2.9％～9.6％(n=6);回收率为87.8％～110.2％.②PCA和t-SNE分析结果表明不同香型烤烟具有明显的分类趋势,其中t-SNE分析的区分效果更明显;HCHMA将样品划分为8类,与香型和产地对应较好.③Amadori化合物测定结果结合多元统计分析方法,可为烤烟香型和产地分析、烟叶品质评价、配方设计优化提供技术支持.

为考察不同卷烟产品挥发性物质的差异,剖析不同卷烟产品香气风格特征,选取5款不同品牌市售卷烟,基于顶空气相-离子迁移谱(HS-GC-IMS)开展卷烟挥发性物质研究,采用相对气味活度值法(ROAV)分析不同卷烟特征香气物质.HS-GC-IMS结果表明,5款卷烟产品的挥发性有机物组分大致相同,但不同化合物的含量之间存在较大差异;ROAV分析结果表明,主要挥发性物质为醛类、酮类、醇类和酯类,对卷烟香气有重要贡献的物质包括糠硫醇、1-辛烯-3-酮、呋喃醇、3-甲基丁醛、乙酸异戊酯等,化合物间含量和感觉阈值的差异影响了其对卷烟香气风格的贡献度,进而影响卷烟的风格特征.借助HS-GC-IMS和ROAV值可以剖析不同卷烟特征香气物质,为卷烟产品的风格分析和品质评定提供一定技术支持.

卷烟纸主要由纤维、填料和助燃剂构成,可直接参与烟支的燃烧.助燃剂(有机钾盐、钠盐)是卷烟纸的重要添加成分,可以提高卷烟纸的燃烧速度,减少抽吸口数,降低卷烟抽吸期间的燃烧温度、CO 量和焦油量,从而降低卷烟的危害性[1-5],其含量直接关系烟支的燃烧性能、吸味及安全性能[6-8].为最大程度保证吸烟者的抽吸体验和烟支的安全性能,助燃剂的含量必须控制在一定水平[9-12].

建立了气相色谱-串联质谱法(GC-MS/MS)同时测定香精和烟草中16种致香成分的分析方法.香精样品经振荡提取、烟草样品经微波辅助萃取后,采用GC-MS/MS多反应监测(MRM)模式进行测定,内标法定量.16种致香成分的线性范围为0.1～10.0μg/mL,在三个不同添加水平下的平均回收率为81.3％～107.4％,相对标准偏差(RSD)为2.2％～10.9％,检出限(LOD)均在0.002～0.500μg/mL.该方法简便快速、选择性好、灵敏度高,为烟草复杂基质中多种致香成分检测提供了一种高效、准确的分析方法.

Abstract A novel analytical method for the simultaneous determination of inorganic tin and organotin in tobacco was established for the first time. The extraction efficiencies of methanol, n-hexane, dichloromethane, ethyl acetate and the mobile phase were investigated. The mobile phase was selected to promote the extraction of tin from tobacco. Eight species of tin including inorganic tin (IT), trimethyltin (TMT), monophenyltin (MPhT), monobutyltin (MBT), diphenyltin (DPhT), dibutyltin (DBT), triphenyltin (TPhT) and tributyltin (TBT) were effectively separated and determined within 25 min using high-performance liquid chromatography – inductively coupled plasma – mass spectrometry (HPLC-ICP-MS). The detection limits were from 0.18 to 0.43 ng mL−1, and the recoveries were between 73.9% and 98.4%. The developed method was successfully employed to analyze tobacco samples. The results showed that inorganic tin was the major component of Sn in the tobacco samples with trace quantities of organotins also detected.

采用超声提取法处理卷烟纸样品,微波消解法处理烟丝及香精样品,电感耦合等离子体质谱法(ICP-MS)同时测定样品中钾、钠、钙和镁元素含量,控制卷烟产品质量稳定性.钾、钠、钙和镁的检出限分别为3.00、0.59、4.53、0.62 μg/L,加标回收率为88.4％～112.0％.采用该方法对不同批次的烟丝样品、卷烟纸样品及香精样品中钾、钠、钙、镁元素含量进行了测定,考察了批次间的稳定性,并对同一规格不同厂家生产的卷烟纸中元素含量进行了对比分析.

Using tobacco as raw material,response surface methodology (RSM) was applied to optimization of supercritical-CO2 fluid extraction (SCFE) of essential oil from tobacco,and chemical constituents of the essential oil were analyzed by gas chromatography-tandem mass spectrometry (GC-MS/MS).As shown by the results,the optimized extraction conditions were 20 422 kPa of extraction pressure,38 ℃ of extraction temperature and 56 min of extraction time,and the yield of essential oil found was 0.73％ under the extraction conditions.A total of 60 chemical constituents were separated and identified from the essential oil by SCAN model in GC-MS/MS,and the value of total peak areas of 60 chemical constituents was more than 90％ of the total chromatographic peak area by MRM model in GC-MS/MS.RSDs (n =10) of retention time of each chemical composition were all less than 1.5 ％,and RSDs of the relative peak areas were all less than 10.0％.

采用高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)联用技术建立了烟草中硒的形态分析方法.烟草样品采用0.10 mol/L HCl超声提取30 min,经离心、过膜后引入HPLC-ICP-MS进行分析.使用Hamilton PRP X-100阴离子交换柱,以20 mmol/L柠檬酸水溶液为流动相(pH=7.0),流速1.2 mL/min,优化条件下实现了6种硒形态的分离.质谱采用He碰撞模式,硒代胱氨酸、亚硒酸根、甲基硒代半胱氨酸、硒酸根、硒脲、硒代蛋氨酸检出限分别为1.20、0.34、1.65、0.13、3.25和0.65 ng/mL.该方法操作简单、快速、灵敏度高,精密度好,加标回收率在86.1％～95.8％之间,适用于烟草中硒元素形态分析.

Objective] To research the transfer volume and law of heavy metal before and after cigarette smoking, and to provide references for reducing the damage of cigarette products.[ Method] Two pretreatment methods of microwave digestion and acid extraction were used to process the ash content, total particulate matter of mainstream smoke ( TPM) and cigarette filter rod.Detection results of heavy metal elements were compared by the two methods.[ Result] The microwave digestion method was better than acid solution extraction method on analysis of TPM, but not so good on analysis of ash and filter rod.Meanwhile, the migration amount and migration rate were studied, which showed that most heavy metal elements were escaped with lateral flow, which was between 66.89%-95.48%.and Hg was mostly escaped with lateral flow.Except Hg, other heavy metal elements were separately found in ash, TPM and filter rod.Cr, Ni, As and Se were mostly residual in ash, followed with TPM.And filter rod was the least, while Cd and Pb were just in the reverse order.Normally, 5% or less of the heavy metal elements were transferred to TPM, only a small part of which could reach 5% -10%.[ Conclusion] Most of the heavy metal elements are taken by lateral flow, ash and filter rod, while the migration amounts of mainstream smoke are extremely low.

采用高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)联用技术建立了烟草中铬元素形态分析方法.采用Hamilton PRP X-100阴离子交换柱,对盐溶液种类、流动相的浓度、pH值、EDTA浓度、络合温度等条件进行了考察.在0.100mol/L硝酸铵水溶液为流动相,pH=7.0,流速为1.0 mL/min条件下达到了Cr(Ⅲ)与Cr(Ⅵ)最佳分离效果,检出限分别为0.048ng/mL、0.054 ng/mL.在0.5～20 ng/mL线性范围内,Cr(Ⅲ)与Cr(Ⅵ)的R2分别为0.9998和0.9996.烟草样品采用20 mmol/LEDTA-2Na溶液在50℃条件下超声提取60 min,然后通过离心、过膜、进样分析.该方法前处理操作简单、灵敏度高、准确性和精密度好,适用于烟草中铬元素形态分析.

建立烟草的气相色谱-串联质谱(GC-MS/MS)指纹图谱,对烟草进行内在品质控制.采用同时蒸馏萃取法(SDE)提取烟草挥发油,进行GC-MS/MS分析,通过10批样品的分析和对照,标示出39个主要共有峰,以夹角余弦和欧氏距离两种方法评价图谱的相似性.结论表明,该方法精密度、稳定性和重现性良好,尤其是定量准确,特别适用于控制烟草的内在质量稳定.

建立了气相色谱-串联质谱(GC-MS/MS)法同时测定烟草中烟碱、降烟碱、麦斯明、假木贼碱和新烟草碱等5种生物碱的分析方法.以甲醇和NaOH溶液混合溶剂作提取溶剂,样品经加速溶剂萃取(ASE)萃取后,利用GC-MS/MS的多反应监测模式(MRM)测定,内标法定量.5种生物碱的检出限在0.06 ～0.12 μg/mL之间,加标回收率介于88.9％～106.8％,相对标准偏差(RSD)均小于6％.方法适用于批量烟草样品中生物碱的快速测定.

A high performance liquid chromatography and inductively coupled plasma mass spectrometric( HPLC-ICP-MS) method has been developed for the determination of 4 arsenic species as arsenite( As( III)),arsenate( As( V)) monomethylarsonic acid( MMA) and dimethylaronic acid( DMA) in tobacco. Tobacco samples were pretreated by ultrapure water,and the separation was performed on an anion-exchange column with the mobile phase composition of 30 mmol /L ammonium carbonate solution. The limits of detection( LOD) were0. 15 ng /mL( As( III)),0. 16 ng /mL( As( V)),0. 17 ng /mL( MMA) and 0. 16 ng /mL( DMA),respectively. The average spiked recoveries were between 73. 8% and 107. 6%,and relative standard deviations( n =3) were below 8.0%. This method has the advantages of simple operation,good separation effect,high sensitivity and fast analytical speed etc.