滤嘴对卷烟主流烟气中挥发性羰基化合物截留效率的测定

本文采用HPLC和GC分别对国内市场占有率较高的18种牌号卷烟主流烟气及其滤嘴中挥发性羰基化合物的含量进行了测定,并对滤嘴截留挥发性羰基化合物效率和机制进行了探讨。结果表明:卷烟主流烟气中挥发性羰基化合物含量高低的顺序是乙醛、丙酮、甲醛、丙稀醛、巴豆醛、丁酮和丁醛;滤嘴中挥发性羰基化合物含量高低的顺序是甲醛、丁酮、巴豆醛、丁醛、丙稀醛、丙酮和乙醛;滤嘴对羰基化合物截留效率高低的顺序是巴豆醛、丁酮、甲醛、丁醛、丙烯醛、丙酮和乙醛。二醋酸纤维丝束对挥发性羰基化合物的截留效率较聚丙烯丝束好。     

Ⅱ.α, β-不饱和醛、酮、酸的硼氢化反应

对于丙烯醛、甲基丙烯醛、β-甲基巴豆醛、肉桂醛、丁-3-烯酮、异丙叉丙酮、巴豆酸、肉桂酸等多种α,β-不饱和羰基化合物的硼氢化反应进行研究。都能以不同的产率得到饱和的一元醇,因而说明在巴豆醛硼氢化时所出现的二硼酸型的消除反应颇为普遍。依据Brown等关于简单烯烃硼氢化反应的理论,可以对这些反应产物的分配作出满意的说明。     

活性羰基化合物荧光探针的研究进展

活性羰基化合物一直以来被人们称为致癌物和人类毒物,当其浓度升高时,会导致多种疾病,因此,设计开发用于选择性识别和高灵敏检测生物体内的活性羰基化合物的技术具有十分重要的意义.近年来,荧光探针具有操作简单、灵敏度高、选择性好,响应时间短以及能实现实时检测等优势,在活性羰基化合物及其他活性物种如活性氧、活性氮、次氯酸以及硫醇等物质的检测方面获得了快速发展.鉴于活性羰基化合物荧光探针综述方面的报道很少,从探针分子与待测物之间发生的反应类别进行归纳和总结,概括了甲醛、甲基乙二醛、丙二醛以及丙烯醛等活性羰基化合物的荧光探针,并从设计理念、识别机理以及应用等方面进行了描述,还对活性羰基化合物荧光探针的设计和应用前景提出了展望.     

聚丙烯醛及其共聚物的膦化反应

用游离基聚合法将丙烯醛及其它烯类单体制成丙烯醛均聚物、丙烯醛-苯乙烯共聚物及丙烯醛-二乙烯苯共聚物,从其红外光谱图上,知聚丙烯醛具有羰基、羟基、碳—碳双键和大量的醚键,聚丙烯醛与羟氨盐酸盐反应后,红外光谱图不再显示有羰基和醚键;与氢氧化钠反应后,羰基增高与醚键有所下降,这些特征表明:聚丙烯醛的羰基与醚键是活泼的。 不同组成的丙烯醛—苯乙烯共聚物,其红外光谱有差别,苯乙烯含量低的共聚物,羰基波峰小,醚键波峰高,当苯乙烯量增至与丙烯醛的克分子数约相同时,羰基波峰高,醚键波峰小,这表明苯乙烯与丙烯醛共聚后,可减少聚丙烯醛的成环反应,由于这个缘故,苯乙烯—丙烯醛共聚物及二乙烯苯(含量不能过高)—丙烯醛共聚物的膦化程度比丙烯醛的均聚物高,若苯乙烯及二乙烯苯的含量不太大,甚至共聚物的磷含量及交换量也较均聚物高。 将制成的均聚物、共聚物在不同条件下(改变反应时间、反应温度及不同溶剂)与三氯化磷反应,然后用醋酸分解,得到α-羟基二元磷酸,在室温(20℃)反应24小时,可得稳定的磷含量及交换量;温度升高,(不超过75℃)反应速度加快。用高介电常数溶剂及混合溶剂,能得到较高磷含量及交换量的产品。 由于均聚物及共聚物的磷化反应不完全,同时所存在的羰基能起Cannizzaro反应,故磷化物     

卷烟主流烟气中挥发性羰基化合物分析研究进展

挥发性羰基化合物是卷烟烟气中主要有害成分之一,在抽吸卷烟的过程中会不同程度地刺激人体的感觉器官和呼吸系统,长期吸入会对人体造成严重的危害。文章介绍了卷烟主流烟气中挥发性羰基化合物的形成机制和前提物,综述了羰基化合物的捕集方法、衍生化和检测手段。     

微波辐射下干反应脱肟成酮的一种新方法

肟已被广泛用于羰基化合物的表征、纯化以及酰胺的合成[1 ] 。人们可以从羰基和非羰基化合物来制备肟 (Ｂａｒｔｏｎ反应[2 ,3] )。因此 ,肟的脱肟成酮也是合成羰基化合物的一种方法。近年来 ,文献中不断有各种脱肟试剂和催化剂 ,如 :三氧化铬 硅胶[4] 、镍 (Ⅱ )复合物[5] 等的研究报道。但这些方法都是在液相中进行的 ,通常需要计量或过量的有机试剂 ,而且反应时间长、产率低[6] 。为了寻找高效的脱肟方法 ,微波辐射下的干反应脱肟研究已愈来愈引起人们的兴趣[1 ,7] ,它具有反应速度快、副反应少、产率高等优点。前文[8] 我们报道了用甲酸…     

LaCO几何、电子结构和化学键的研究

长期以来 ,人们对希土羰基化合物的存在一直持怀疑态度[1 ] ,尽管 Slater[2 ] 等用基质隔离法合成部分希土羰基化合物的成功消除了这种疑问 ,但由于此类化合物高度的不稳定性 ,其几何结构至今尚未确定 ,希土羰基化合物的电子结构和化学键更是困扰人们的重要课题。希土羰基化合物是具有 L n- C键的最简单希土有机金属化合物 ,其结构和性能具有一定的代表性 ,探讨其化学键合本质及其不稳定的原因对深入了解希土金属有机化合物结构和性能的关系具有十分重要的意义。一 .研究方法本文采用洪功义、黎乐民等[3 ] 改进的高精度求解密度泛函理论方…     

取代戊二烯Ti,V羰基化合物的谱学研究

利用IR，EPR和UV-VIS方法对系列取代戊二烯基钛，钒羰基化合物进行了表征，用EHMO方法对开环夹心化合物[2,4-(CH_3)_2C_2H_5]_2VCO和开、闭环夹心化合物[2,4(CH_3)_2C_5H_5](C_5H)5)VCO进行了计算，对开环夹心羰基化合物，开、闭环夹心羰基化合物及闭环夹心羰基化合物进行了比较．结果表明，开、闭环夹心羰基化合物的性质介于开环夹心羰基化合物和闭环夹心羰基化合物之间，且更接近于开环夹心羰基化合物，开环配体与Ti，V间的化学键较强，对于化合物性质影响较大．     

对2,4-二硝基苯腙法分析甲醛和乙醛酸混合样品的几点改进

甲醛和乙醛酸是乙醇胺、甘氨酸及其N-烷基化合物的热分解产物。用2,4-二硝基苯腙法测定低浓度羰基化合物的含量是目前经常采用的方法。但要用该法分别测定混合样品中甲醛和乙醛酸的含量是困难的,而且试剂处理也太繁琐。我们用稀盐酸水溶液代替无羰基的甲醇作溶剂,用分析纯的2,4-二硝基苯肼代替二次纯化试剂,配制的溶液用四氯化碳处理后直接使用,获得了满意的结果。甲醛、乙醛酸和试剂反应生成2,4-二硝基苯腙后,由于R基的不同,其亲水性有很大差异。用四氯化碳萃取,甲醛的2,4-二硝基苯腙到四氯化碳相,而乙醛酸的2,4-二硝基苯腙则仍留在水     

直接衍生/高效液相色谱法分析水基胶中羰基化合物

建立了直接衍生/高效液相色谱分析水基胶中8种痕量羰基化合物(甲醛、乙醛、丙酮、丙烯醛、丙醛、丁烯醛、2-丁酮和丁醛)的方法.对影响分析效率的因素进行了考察,确定最佳衍生条件为:水基胶样品与2,4-二硝基苯肼衍生剂在40℃下反应20 min;最佳色谱分析条件为:采用DIONEX Acclaim Explosives E2...     

Gas chromatography-mass spectrometry of carbonyl compounds in cigarette mainstream smoke after derivatization with 2,4-dinitrophenylhydrazine

An improved gas chromatography-mass spectrometry (GC-MS) method was described for the analysis of carbonyl compounds in cigarette mainstream smoke (CMS) after 2,4-dinitrophenylhydrazine (DNPH) derivatization. Besides formaldehyde, acetaldehyde, acetone, acrolein, propionaldehyde, methyl ethyl ketone, butyraldehyde, and crotonaldehyde that are routinely analyzed in cigarette smoke, this technique separates and allows the analysis of several C4, C5 and C6 isomeric carbonyl compounds. Differentiation could be made between the linear and branched carbon chain components. In cigarette smoke, the branched chain carbonyls are found at higher level than the linear chain carbonyls. Also, several trace carbonyl compounds such as methoxyacetaldehyde were found for the first time in cigarette smoke. For the analysis, cigarette smoke was collected using DNPH-treated pads, which is a simpler procedure compared to conventional impinger collection. Thermal decomposition of DNPH-carbonyl compounds was minimized by the optimization of the GC conditions. The linear range of the method was significantly improved by using a standard mixture of DNPH-carbonyl compounds instead of individual compounds for calibration. The minimum detectable quantity for the carbonyls ranged from 1.4 to 5.6 microg/cigarette.     

Pyrolysis behavior of pectin under the conditions that simulate cigarette smoking

In this paper, the formation mechanism of pyrolysis gases released during the pyrolysis of pectin under the conditions that simulate cigarette smouldering was investigated by thermogravimetric analysis coupled to Fourier transform infrared spectrometer (TG-FTIR). Moreover, the combustion behavior of pyrolysis gases was studied by micro-scale combustion calorimetry (MCC). TG-FTIR results illustrated that the composition of the gaseous products was mainly composed of CO₂, H₂O, CO, methanol, methane and carbonyl compounds. MCC results demonstrated that the combustion of pectin was mainly determined by the prolysis gases formed in the temperature range of 200-300 °C. Flash pyrolysis experiment in combination with high performance liquid chromatography (FPy-HPLC) was used to study the pyrolytic formation of eight carbonyl compounds (i.e. formaldehyde, acetaldehyde, acetone, acrolein, propionaldehyde, crotonaldehyde, methyl ethyl ketone and butyraldehyde) during the pyrolysis of pectin under the pyrolysis conditions of cigarette puffing. Results demonstrated that pyrolysis temperature influenced the formation of acetaldehyde, acrolein, propionaldehyde and butyraldehyde greatly, while nitrogen flow affected the generation of formaldehyde, acetone, crotonaldehyde and methyl ethyl ketone deeply.     

快速分离柱高效液相色谱法测定卷烟主流烟气中的主要羰基化合物

选择2,4-二硝基苯肼(DNPH)为羰基化合物的衍生化试剂,建立了快速分离柱高效液相色谱测定卷烟主流烟气中8种羰基化合物的方法。采用经2,4-二硝基苯肼酸性溶液处理过的剑桥滤片捕集烟气,再用含2%（体积分数）吡啶的乙腈溶液进行萃取,以ZORBAX Stable Bound色谱柱(50 mm×4.6 mm,1.8 μm)进行快速分离,最后由二极管阵列检测器于365 nm下进行检测。该方法的回收率为89.1%～99.2%,相对标准偏差（RSD)在6.0%以下。该方法分析时间短,流动相消耗少,且操作简便、重复性好、回收率高。     

The pyrolysis of cigarette paper under the conditions that simulate cigarette smouldering and puffing

The combustion properties and pyrolysis behavior of cigarette paper under the pyrolysis conditions of cigarette smouldering were investigated by micro-scale combustion calorimetry (MCC), thermogravimetric analysis coupled to Fourier transform infrared spectrometer (TG-FTIR), respectively. MCC results demonstrated that the combustion and pyrolysis behavior are influenced by heating rate obviously. TG-FTIR results illustrated that the composition of the gaseous products were mainly composed of CO₂, H₂O carbonyl compounds, CO, and methanol. Flash pyrolysis experiment in combination with high performance liquid chromatography (FPy-HPLC) was used to study the pyrolytic formation of eight carbonyl compounds (i.e., formaldehyde, acetaldehyde, acetone, acrolein, propionaldehyde, crotonaldehyde, methyl ethyl ketone, and butyraldehyde) during the pyrolysis of cigarette paper under the pyrolysis conditions of cigarette puffing. Moreover, the solid char formed after the flash pyrolysis experiments were studied by X-ray photoelectron spectroscopy (XPS). It had been found that the pyrolysis temperature influenced the formation of carbonyl compounds and the composition of char greatly.     

卷烟主流烟气中8种羰基化合物的超高效液相色谱测定

建立了超高效液相色谱(UPLC）对卷烟主流烟气总粒相物中甲醛、乙醛、丙酮、巴豆醛等8种羰基化合物的测定方法。采用经2,4-二硝基苯肼酸性溶液处理过的剑桥滤片捕集烟气,再用含2%(体积分数）吡啶的乙腈溶液进行萃取,以KinetexTM C18(150 mm×2.1 mm,2.6 μm）为色谱柱,水-乙腈(35∶65）和水-乙腈-四氢呋喃-异丙醇(59∶30∶10∶1）为流动相梯度洗脱,采用二极管阵列检测器进行检测,分析时间为20 min。结果表明,该方法的相关系数r2≥0.999 97,检出限为25.81~67.74 ng/cig,平均加标回收率为95%~99%,相对标准偏差为1.4%~5.8%。各组分峰分离度高、分析时间短、流动相耗量少、结果准确可靠。用该方法对20种不同卷烟牌号样品中8种羰基化合物的含量进行测定,结果满意。     

Polarographic determination of semicarbazones

Acetone, methyl isobutyl ketone, acetaldehyde, formaldehyde, cyclohexanone, butyraldehyde, crotonaldehyde, and acrolein semicarbazones all give polarographic waves suitable for quantitative analysis in an acetate buffer at pH 4.6 .The half-wave potentials are —1.3, —1.3, —1.16 —1.05, —1.2,—1.11, —1.06,–0.99 V vs. S.C.E., respectively, for the compounds listed above. The diffusion current constants of these compounds average approximately 7 in the concentration range of 10^-2 to 10^-1 mM, giving an extremely sensitive method of carbonyl compound analysis. A supporting electrolyte that is 0.1M each in acetic acid, sodium acetate, sodium chloride, and semicarbazide, and 0.0016% in Triton X-100, is satisfactory both for polarograph analysis and for the quantitative absorption of acetone, acetaldehyde, cyclohexanone, and crotonaldehyde from air samples by means of a scrubber.     

The generation of carbon monoxide and carbonyl compounds in reconstituted tobacco sheet

In recent years, reconstituted tobacco sheet (RTs) has played an increasingly significant role in tobacco industry. The yields of CO and carbonyl compounds (formaldehyde, acetaldehyde, acetone, acrolein, propanal, butenal, 2-butanone, and butyraldehyde) in cigarette mainstream smoke of RTs and their formation mechanisms were investigated in this paper. Self-made RTs (SRTs) was studied and compared with foreign Mauduit RTs (MRTs) and three commercial tobacco leaves on routine chemical constituents, thermal behavior, and subsequent gaseous products evolution. The cigarette smoking results illustrated that the yields of CO (2.9 mg per puff) and carbonyl compounds (about 208 μg per puff) in mainstream smoke of SRTs and MRTs were at the same level, and obviously higher than those of three commercial tobacco leaves. The routine chemical constituent results demonstrated that bright tobacco and oriental tobacco contained particularly higher contents of reducing sugar and total sugar than RTs, while burley tobacco had a high content of nitrogen compounds. The thermal behavior results showed that SRTs (11.6 % min^?1) and MRTs (14.5 % min^?1) presented higher maximum mass-loss rate than bright tobacco (7.8 % min^?1), burley tobacco (7.1 % min^?1), and oriental tobacco (6.8 % min^?1). The thermal decomposition of saccharides and combustion of residual char played the most important roles in mass-loss and gaseous products formation. The decomposition of saccharides and incomplete combustion of carbonized residual char primarily contributed to the formation of CO, while carbonyl compounds evolution was mainly attributed to the decomposition of saccharides alone.     

卷烟主流烟气中挥发性醛酮和苯的P&T-GC分析

挥发性羰基化合物和苯是卷烟烟气中重要的有害物质,为此建立了P&T-GC法测定卷烟样品主流烟气中的乙醛、丙醛、丁醛、丙酮、2-丁酮和苯.该方法不用2,4-二硝基苯肼(DNPH)衍生化,不用有机溶剂萃取和浓缩,减少了对环境的污染,具有灵敏度高、检出限低、定量准确、操作简便等特点.结果表明:方法有较好的重复性,相对标准偏差在5.39%以下;检出限为0.85 ng/支～6.55 ng/支;6种物质的回收率在89.22%～98.21%之间.     

Determination of Volatile Carbonyl Compounds in Cigarette Smoke by LC-DAD

An effective and rapid method, use of a 2,4-dinitrophenylhydrazine (DNPH)-treated Cambridge filter and high-performance liquid chromatography (HPLC) with diode-array detection (DAD), has been used for determination of low-molecular-mass carbonyl compounds in cigarette smoke. Different chromatographic mobile phases were investigated and the optimized mobile phase was a gradient prepared from water–acetonitrile–tetrahydrofuran (THF)–iso-propanol, 59:30:10:1 (v/v) (mixture A) and acetonitrile–water, 65:35 (v/v) (mixture B). Under the optimized chromatographic conditions, the 2,4-dinitrophenylhydrazones of formaldehyde, acetaldehyde, acrolein, acetone, propionaldehyde, 2-butanone, and iso-butyraldehyde were separated completely in an 18 min chromatographic run. The concentration of acid, which has large effect on carbonyl-DNPH derivatization, was investigated by adding different volumes of perchloric acid. The DNPH-treated Cambridge filter was convenient and effective compared with conventional methods used to collect and derivatize the carbonyl compounds present in cigarette smoke. Validation of the method showed it to be effective, precise, accurate, and linear over the range of concentrations of analyzed.     

New insights into the formation of volatile compounds in mainstream cigarette smoke

A sampling system has been set up to monitor a group of volatile smoke analytes (nitric oxide, acetaldehyde, acetone, benzene, toluene, 1,3 butadiene, isoprene and carbon dioxide) from mainstream cigarette smoke on a puff-resolved basis. The system was able to record gas evolution profiles during puffing and interpuff periods without interruption (e.g. taking clearing puffs). Gas phase smoke analytes were sampled as close to the mouth end of the cigarette filter as possible in order to minimise any dead volume effect. The results revealed that, for some volatile species, a significant fraction (e.g. up to 30% for benzene) in the cigarette mainstream smoke had been generated during the preceding smoulder period. These species were trapped or absorbed within the cigarette rod and then subsequently eluted during the puff. The identification of the two sources of the mainstream smoke, a smouldering source and a puffing source, has not been reported before. The observation contributes to the fundamental knowledge of the cigarette smoke formation and may have implications on wider smoke chemistry and associated effects.