高效液相色谱-蒸发光散射检测法在烟用香精料液中水溶性糖及山梨醇分析中的应用

建立了高效液相色谱-蒸发光散射(HPLC-ELSD)同时检测烟用香精料液中6种水溶性糖及山梨醇的分析方法。方法选用Isolute ENV+固相萃取(SPE)小柱净化样品提取液,以Prevail Carbohydrate ES高效糖柱(250 mm×4.6 mm, 5 μm)作为分析柱,以乙腈和水(75:25, v/v)作为流动相,在1.0 mL/min流速下实现目标物的良好分离;蒸发光散射检测器漂移管温度为79 ℃,载气流速为2.0 L/min。方法针对各目标物建立双对数工作曲线,线性范围约为0.06～1.2 g/L,检出限为12～26 mg/L,样品加标回收率为88%～109%。针对蒸发光散射检测器的双对数工作曲线,通过实验进行分析对比,并结合前人的工作,指出目标物的物理化学性质及其在色谱柱上的保留状态和流动相的洗脱能力等都是影响检测信号的因素。     

寡聚酸合锌(Ⅱ)的合成及对烟草病毒病的防治

在水-乙醇介质中,用寡聚酸钾与硫酸锌反应合成的寡聚酸合锌(Ⅱ)配合物,采用正交实验考察了V水∶V乙醇,反应温度,反应时间对螯合反应的影响,最优反应条件为:V水∶乙醇=1∶1;温度60℃;时间5h.通过红外光谱、紫外光谱和差热-热重分析测试手段对配合物进行了表征.红外光谱和紫外光谱均显示,Zn2+与寡聚酸配位.寡聚酸合锌(Ⅱ)配合物中金属配位方式为单齿和双齿配位.热分析表明,配合物稳定性较强.应用寡聚酸合锌(Ⅱ)防治烟草病毒病,试验结果表明寡聚酸合锌(Ⅱ)具有较强的防治烟草病毒病的作用.寡聚酸合锌(Ⅱ)作为新型的抗病毒制剂具有广阔的开发前景.     

烟草中两种紫罗兰醇葡萄糖苷衍生物的分离鉴定及热分析研究

采用传统柱层析技术和高效液相色谱相结合的方法从烤烟中分离出3-氧代-α-紫罗兰醇-β-D-吡喃葡萄糖苷和7,8-二氢-3-氧代-α-紫罗兰醇-β-D-吡喃葡萄糖苷,利用ESI MS、1H NMR、13C NMR进行结构鉴定。为开发热稳定型香原料,在300、600、900℃及氦气环境中对2种糖苷进行了在线热裂解(Py)研究和释香机理讨论,研究表明主要裂解物为烟草重要香味物巨豆三烯酮及其同分异构体和3-氧代-α-紫罗兰醇。首次对3-氧代-α-紫罗兰醇-β-D-吡喃葡萄糖苷进行了热重-红外-气相色谱-质谱联用分析,在265℃时,目标物巨豆三烯酮及其同分异构体快速脱落。该技术不仅方便快速,还能实时地对裂解产物进行鉴定,为天然产物的裂解产物在线分离和鉴定提供了依据。     

片烟在黑龙江自然陈化过程中感官质量变化研究

跟踪鉴定14个复烤烟叶样品在自然陈化7～60个月期间的感官质量变化情况.结果表明:第一,不同产区各部位复烤烟叶在黑龙江地区的自然陈化感官质量随时间变化情况各不相同:浙江香料烟和云南烤烟上部、中部烟叶陈化26～34个月感官质量达到高峰;贵州烤烟、福建烤烟和湖北白肋中部叶最佳陈化时间为34～38个月;贵州烤烟、福建烤烟、河南烤烟、黑龙江烤烟和湖北白肋上部烟叶最佳陈化时间为38～42个月.第二,不同产区烟叶自然陈化期间烟叶质量变化幅度不同,以云南烟叶质量变化最大,黑龙江烟叶质量变化最小.云南、贵州烟叶经自然陈化效果较好.第三,上部烟叶比中部烟叶耐存放,河南烟叶和黑龙江烟叶耐存放,云南烤烟和浙江香料烟不耐存放.第四,烟叶感官总体质量的提高主要由杂气、浓度、香气质和香气量等指标变化引起.     

RP-HPLC法测定烟草中绿原酸含量的研究

采用超声波提取、反相高效液相色谱测定烟叶中绿原酸,用内标法进行定量,并对超声波提取烟叶中绿原酸的提取条件进行了优化,结果表明:用60%的乙醇溶液,在50 ℃、pH 4条件下,超声提取 45 min效果最佳.该法具有良好的线性(相关系数为0.999 9),检测限为 1.4×10-2 mg/10 mL (S/N=3) 加标回收率为 101.5%,方法RSD为1.58%.方法快速、简单、准确.     

低场核磁共振技术分析不同来源水分在烟丝中的分布状态及含水率的研究

采用低场核磁共振分析技术(LF-NMR)对不同来源水处理后的烟丝进行分析,研究了不同处理工艺样品的含水率及水分分布状态的变化。结果表明:水的种类对烘丝关键工序烟丝水分含量及分布状态具有明显影响。其中反渗透水和磁化水处理的样品含水率高于自来水处理后的样品,分别高0.43%和0.72%。得到薄板适宜的加工温度为140~150℃,气流干燥适宜的加工温度为180~210℃。     

Loss of Pendimethalin in Surface Runoff from Plots Untilled and Tilled with Tobacco

Abstract

The loss of pendimethalin (N-(ethylpropyl)-2,6-dinitro-3,4-xylidine), a selective herbicide in runoff water was determined on sandy-clay-loam soil plots cultivated with tobacco in relation with the use of ammonium nitrate limestone as fertelizer, for a period of two years, 1990 and 1991. The surface slope of plots was 11% and the use of fertilizer decreased the soil erosion from a value 617 g/m²to 320 g/m². The runoff of surface waters were between 16-24% of the rainfall amounts. Reduction in pendimethalin in waterways results from water loss by infiltration, sediment loss, and by attachment adsorption on vegetative and organic matter. Surface runoff levels were highest for the first runoff event after herbicide application, 1.5 g/10 m² and initial concentrations were related to the time lapse between herbicide application and the date of the first run-off event. Maximum concentrations were 5.95 and 8.54 μg/L in 1990 and 1991 respectively. Persistence studies showed that pendimethalin concentration in runoff of 0.5 cm soil layer decreased by 88.2%, from 2.46 to 0.29 μg/g within 233 days, in 1990 and by 87.6%, from 2.42 to 0.30 μg/g within 235 days in 1991. After 310 day the concentration of pendimethalin was only 0.1 μg/g.     

Simultaneous determination of nicotine and 3-vinylpyridine in single cigarette tobacco smoke and in indoor air using direct extraction to solid phase

The aim of the present study was to develop a new analytical method of chromatographic determination of two important markers of ETS exposure: nicotine and 3-vinylpyridine (3-ethenylpyridine, 3-EP) in mainstream (MS) and sidestream (SS) smoke of one single cigarette and in indoor air using direct solid phase extraction combined with gas chromatography. The method can be utilised for both nicotine and 3-EP determination in SS and MS of one single cigarette as well as it allows for a precise determination of compound distribution in indoor air. The application of the same analytical method for both kinds of samples allows anticipating indoor air distribution of both analysed compounds in a very precise way. The precision of the method (calculated as a relative standard deviation) was 9.78% for nicotine and 2.67% for 3-EP; whereas the accuracy (evaluated by a recovery study conducted at three different levels) was 70.1 and 87.3%, respectively. The limit of detection was 0.06 µg per cigarette for both nicotine and 3-EP. The method was evaluated by determining the compounds of interest in two commercially available brands of cigarettes as well as in the reference cigarettes 3R4F and also in indoor air polluted with tobacco smoke. Determined levels of compounds of interest in MS varied from 586 to 772 (nicotine) µg per cigarette and from 3.5 to 10.7 (3-EP) µg per cigarette. In SS smoke the level varied from 14,370 to 22,590 (nicotine) µg per cigarette and from 185 to 550 (3-EP) µg per cigarette, whereas levels in indoor air polluted with tobacco smoke varied from 50.1 to 157.3 (nicotine) µg m^?3and from 7.7 to 20.8 (3-EP) µg m^?3.     

基于集成物流网络的路径优化问题探究

由于物流集成网络能够规划物流作业流程,整合物流资源,从而提高物流运作效率,发挥物流规模化优势,因此,本文在集成物流网络的背景下,探讨路径优化问题,在传统的Dijkstra算法基础上,采用了完全二叉树对Dijkstra算法进行改进,并以烟草商业企业为例说明集成物流网络的特点与优势,验证算法的有效性。研究结果表明：改进后的Dijkstra算法能够降低时间复杂度,提高运行效率,为企业大规模的集成物流网络分析应用提供了一种的有效的方法。     

A liquid chromatography-mass spectrometry method for nicotine and cotinine; utility in screening tobacco exposure in patients taking amiodarone

A liquid chromatographic mass spectrometric (LC-MS) assay for the quantification of nicotine and cotinine in human specimens was developed. Human serum and urine (100 μL) were subjected to liquid-liquid extraction. For glucuronidated cotinine, serum was alkalinized and hydrolyzed before extraction. The dried samples were reconstituted and run using gradient flow reverse-phase liquid chromatography with MS detection. The ions utilized for quantification of nicotine, cotinine and milrinone (internal standard) were 162.8, 176.9 and 211.9 m/z, respectively. The mean recoveries were over 80% for cotinine and nicotine with excellent linearity between nominal concentrations and peak area ratios, over a wide concentration range. The percentage coefficient of variation and mean error of the inter- and intra-day validations were <15% for nicotine and cotinine. Analysis of serum from cardiac patients receiving amiodarone suggested that a number of patients were either active smokers or exposed to second-hand smoke. Significant concentrations of nicotine and cotinine were measured in the urine of a known smoking volunteer. The method was highly specific, sensitive and applicable as a tool in detecting and monitoring the passive exposure to tobacco smoke using small specimen volumes (0.1 mL).