Analysis of trace uranium in Indian tobacco samples

The trace uranium concentrations have been determined in tobacco obtained from different brands of commercially available cigarette, beedi, chewing tobacco and also in pan masala, using fission track registration technique. Consumption of tobacco orally or by smoking may result in the intake of radioactive elements into the human body causing hazardous effects. External detector method was employed for the determination of uranium using Makrofol-KG as the fission track detector. The range of uranium was found to vary between 0.066–0.106 ppm, 0.042–0.079 ppm and 0.043–0.092 ppm, in tobacco from samples of cigarette, beedi and chewing tobacco, respectively, and between 0.073–0.203 ppm in pan masala samples.     

Determination of Uranium in Human Hair by Acid Digestion and FIAS-ICPMS

The content of heavy metals in human hair may serve as an indicator of occupational or environmental exposure to metal compounds. However, before such exposure can be determined, the level of the element in a "normal" population must be established. The concentration of uranium in human hair was measured by flow injection — inductively coupled plasma mass spectrometry (FIAS-ICPMS) after acid digestion of the hair samples. All hair samples were rinsed in order to remove external contamination prior to the digestion in a 2:1 solution of concentrated nitric acid and 30% hydrogen peroxide. The limit of detection of the method, for a 50 mg hair sample, was 0.015µg/g, mainly due to the presence of impurities in the hydrogen peroxide. The range of uranium concentration in the initial test group was found to be 0.01–0.18 µg/g. The mean and median values of the entire study population were 0.062 and 0.050 µg U/g hair, respectively. Differences between the following sub-populations: male and female, smokers and non-smokers and people below and above 45 years of age were examined. The only statistically significant difference was found in the latter group (p = 0.03).     

Biosorption of Cadmium,Lead, and Uranium by Powder of Poplar Leaves and Branches

The removal of metal ions from aqueous solutions by biosorption plays an important role in water pollution control. In this study, dried leaves and branches of poplar trees were studied for removing some toxic elements (cadmium, lead, and uranium) from aqueous solutions. The equilibrium experiments were systematically carried out in a batch process, covering various process parameters that include agitation time, adsorbent size and dosage, initial cadmium, lead and uranium concentration, and pH of the aqueous solution. Adsorption behavior was found to follow Freundlich and Langmuir isotherms. The results have shown that both dried leaves and branches can be effectively used for removing uranium, while only branches were found to remove lead and cadmium completely from the aqueous solution. The maximum biosorption capacity of leaves for uranium was found to be 2.3 mg g⁻¹ and 1.7 mg g⁻¹ and 2.1 mg g⁻¹ for lead and cadmium on branches, respectively. In addition, the studied biomass materials were used in removing lead and cadmium from contaminated water and the method was found to be effective.     

Redistribution of uranium and thorium by soil/plant interaction in a recultivated mining area

During the recultivation of the uranium mining area of K?vágósz?l?s (Hungary), the tailings were covered with clay and loess soil layers having a thickness of 30 cm and 100 cm, respectively. In the loess covering layer, acacia (Robinia pseudoacacia), poplars (Populus × albus, Populus × canescens), oak (Quercus pubescens), silver tree (Eleagnus angustifolia) were planted between 1996 and 2004. In order to establish the extent of the uranium and thorium transport from the sludge to the leaves by uptake and translocation processes through roots with a length higher than 1.3 m results in a remarkable redistribution of these pollutants, a gray poplar tree, growing spontaneously in the last uncovered tailing, being selected as reference tree. The U and Th concentrations in the leaves of the above-mentioned trees, in the covering layers as well as in the original sludge were determined by inductively coupled plasma sector field mass spectrometry (ICP-SF-MS). Generally, the Th concentration of the soils was about 4 times higher than that of uranium, while uranium concentration was about 10-130 times higher than that of thorium in the leaf samples and its concentration ranged from 28 to 1045 ng g^− 1, the last value belonging to the poplar tree growing on the last uncovered tailing. In order to assume the mobility and bioavailability of uranium if the dry leaves fall down, the uranium species in the leaves of the poplar tree growing in the uncovered reservoir were determined applying ultrasound-assisted extraction with distilled water and ammonium acetate as well as high performance liquid chromatographic (HPLC)-ICP-SF-MS technique. About 20% of total uranium could be extracted in form of uranyl cations and a presumably negatively charged uranium compound. Estimations revealed that the annual increment of U in the soil surface layer due to the dead fallen leaves in case of the investigated gray poplar (Populus × canescens) is about 1.2%.     

Trace quantities of uranium in some Indian chewing tobaccos as determined by fission track analysis

The sandwiched pellet technique using Makrofol-E plastic track detectors has been employed to determine trace quantities of uranium in nine brands of flavored chewing tobaccos consumed by the Indian population. In this technique the nuclear reaction,²³⁵U(n,f), is used for the quantitative estimation of uranium. The maximum value of uranium (1.88 ppm) has been found in raw tobacco leaves (Surti), while the minimum (0.13 ppm) in Tulsi (Double Zero brand). Other seven brands showed intermediate values of U-contents which are also reported in this paper. These values are compared with the U-contents reported in the literature for other forms of tobaccos.     

Neutron activation analysis of uranium in human bone,drinking water and daily diet

Uranium in human bone, drinking water and daily diet has been determined by neutron activation analysis using the²³⁸U(n, γ)²³⁹U reaction. An improved scheme for the separation of the²³⁹U is proposed; with this scheme, after neutron irradiation in a 100 kW TRIGA reactor, a uranium content as low as 5·10⁻¹¹ g can be determined reliably, rapidly and easily. A wide range of uranium concentrations, from about 0.1 ppb up to about 10 ppb has been found in the bones of normal Japanese. Water from several Japanese city water services, and the daily diet taken in two Japanese cities, have been found to contain an average 9·10⁻⁹ g/l and 1.5 μg per person-day uranium, respectively.     

Comparison of willow and sunflower for uranium phytoextraction induced by citric acid

This study deals with an efficiency of a low dose of citric acid soil application on phytoextraction of uranium. Willow (Salix spp.) and sunflower (Helianthus annus L.) were tested in this experiment with contaminated soil. The enhancing of uranium bioaccumulation was confirmed, but in contrast to previous studies, the highest quantity of uranium was accumulated in leaves. After 5 weeks of citric acid treatment, willow was more efficient in the uptake and translocation of uranium than sunflower. The transfer coefficient calculated for leaves increased from 0.033 (control) to 0.74, or 0.56 after five doses of 5 mmol of citric acid per 1 kg of soil for willow or sunflower, respectively. The uptake characterized by the total U content achieved 88 and 108 mg kg⁻¹ in relation to the above ground parts of sunflower and willow, respectively. Even though both plants accumulated U in their above ground parts in significant rate, they employed diverse ways to achieve it. At the end of the treatment, the physiological condition of the plants enabled us to continue this method.     

Risk Assessment of Passive Smoking Based on Analysis of Hair Nicotine and Cotinine as Exposure Biomarkers by In-Tube Solid-Phase Microextraction Coupled On-Line to LC-MS/MS

Passive smoking due to environmental tobacco smoke is a serious public health concern because it increases the risk of lung cancer and cardiovascular disease. However, the current status and effect of passive smoking in various lifestyles are not fully understood. In this study, we measured hair nicotine and cotinine levels as exposure biomarkers in non-smokers and assessed the risk from the actual situation of passive smoking in different lifestyle environments. Nicotine and cotinine contents in hair samples of 110 non-smoker subjects were measured by in-tube solid-phase microextraction with on-line coupling to liquid chromatography-tandem mass spectrometry, and self-reported lifestyle questionnaires were completed by the subjects. Nicotine and cotinine were detected at concentrations of 1.38 ng mg⁻¹ and 12.8 pg mg⁻¹ respectively in the hair of non-smokers, with levels significantly higher in subjects who reported being sensitive to tobacco smoke exposure. These levels were also affected by type of food intake and cooking method. Nicotine and cotinine in hair are useful biomarkers for assessing the effects of passive smoking on long-term exposure to environmental tobacco smoke, and our analytical methods can measure these exposure levels in people who are unaware of passive smoking. The results of this study suggest that the environment and places of tobacco smoke exposure and the lifestyle behaviors therein are important for the health effects of passive smoking.     

Liquid chromatography/mass spectrometry-based metabolic profiling to elucidate chemical differences of tobacco leaves between Zimbabwe and China

An approach was developed for extracting and analyzing the chemical components of tobacco leaves based on solvent extraction and rapid & resolution liquid chromatography/quadrupole time-of-flight mass spectrometry analysis. Two solvents with different polarities were used to extract hydrophilic components and hydrophobic components, respectively, the combined analytical data can provide a "global" view of metabolites. Based on the evaluation of parallel samples, it was found that this approach provided good repeatability, accurate and reliable profiling data, and is suitable for the metabolomics study of tobacco leaves. In order to find the chemical component differences of tobacco leaves, 56 samples from Zimbabwe and China were analyzed using the developed method. The metabolite data were processed by multivariate statistic technique; an obvious group classification between Zimbabwe and China was observed, 14 significantly changed compounds were found, and 9 of them were identified.     

Dissipation dynamics and final residues of flutriafol in tobacco and soil using ultrasound-assisted extraction before liquid chromatography/tandem mass spectrometry

The dissipation dynamics and final residues of flutriafol on tobacco plant and soil were studied under field conditions. The residues of flutriafol in soil, green tobacco leaves and cured tobacco leaves were extracted by ultrasound-assisted extraction, cleaned up by dispersive solid-phase extraction and detected by liquid chromatography with tandem mass spectrometry. The limits of detection of flutriafol in soil, green tobacco leaves and cured tobacco leaves were 0.006, 0.033 and 0.033 mg·kg^?1, respectively. The limits of quantification of flutriafol in soil, green tobacco leaves and cured tobacco leaves were 0.02, 0.1 and 0.1 mg·kg^?1, respectively. Recoveries were 72.9–102% with relative standard deviations of less than 12% in soil and tobacco matrix. For field experiments, the half-lives of flutriafol in soil and green tobacco leaves were 9.2–11.5 and 9.5–11.1 days, respectively. At harvest, the final residue levels of flutriafol in cured tobacco leaves collected 21 days after one application at the recommended dosage were below 2.0 mg/kg. The maximum residue limit maximum residue limit (MRL) for flutriafol in tobacco has not yet been established in any countries. The data could help the Chinese Government to establish the MRL of flutriafol in tobacco and provide guidance on the proper use of flutriafol.     

A liquid chromatography–tandem mass spectrometry method to simultaneously determinate dichlorvos and phoxim in tobacco

A simple pretreatment method with liquid chromatography–tandem mass spectrometry (LC–MS/MS) was developed and validated to simultaneously determine dichlorvos and phoxim in tobacco and soil matrices. Satisfactory linearity (R² ≥ 0.9991) of the method was obtained for both analytes. The limits of detection and limits of quantification for dichlorvos and phoxim in three matrices were 0.0015–0.006 and 0.005–0.02 mg/kg, respectively. Average recoveries were 78.24–92.21% for dichlorvos and 76.62–100.51% for phoxim in soil, green tobacco leaves and cured tobacco leaves. The intra‐ and inter‐day relative standard deviations were <6%. The established method was successfully applied for the residual analysis of dichlorvos and phoxim in real soil and tobacco samples. The results indicated that the established method could be used to detect trace amounts of dichlorvos and phoxim in tobacco. The data could also help the Chinese government establish maximum residue limits of dichlorvos and phoxim on tobacco and establish proper and safe use of dichlorvos and phoxim on tobacco plants in China.     

稀土在烤烟植株中的分布及其对烟叶化学成份影响的研究

作为一种生理活性物质,稀土施用在烟草上平均增产11％,上中等烟比例提高7．53％左右,稀土应用于烤烟大部分限于田间试验,缺深入的机理研究^[2-4]。本试验用低浓度混合硝酸稀土喷施烤烟叶面,研究了稀土在烤烟植株中的含量,分布及土壤中可溶态稀土的变化情况及稀土对烟叶化学成份的影响,旨在为烤烟施用稀土提供科学依据。     

Comparison of selenium content in human hair from different individuals in different countries,by76Se(n,γ)77mSe reaction

Samples of hair from 370 subjects were analysed by neutron activation. The samples were taken from residents of nine different countries: Japan, France, Ivory Coast, Brasil, Paraguay, Canary Islands, Papua New Guinea, Italy and New Zealand. The selenium determination was made using the⁷⁶Se(n,)^77mSe reaction.It was found that the average selenium concentration in the hair of Japanese subjects, both those living in Japan and those living in foreign countries was higher (total average: 0.59±0.14 mg/kg) than those of subjects from other countries (total average: 0.42±0.13 mg/kg).Our results from the determination of the selenium concentration in the hair of individuals from different countries show significant differences between different countries, nevertheless, the selenium content in human hair was small amounts. Since this is likely due to differences in diet. This method was able to analyze quickly for many samples.     

不同烟草生物质热解释放致香物质的研究

采用烟叶和烟梗为原料,使用热裂解气相色谱法对烟草的燃烧时间、燃烧温度进行控制,精确模拟实际烟草致香物质释放环境,精确捕获、并半定量物质,从而在实验室模拟、分析、研究烟草燃烧物中致香物质的组成和特点。研究分别考察了两种生物质在500℃、550℃下释放的致香物质组成。结果表明,烟梗、烟叶中元素组成中硫、氮两种元素含量低,而C/H比值两种烟草生物质均较高。两个热解温度下烟叶的热解产物中致香物质的含量均明显高于烟梗。升高热解温度均有利于获得更高相对含量的热解成分。烟叶热解产物中烯烃类物质相对含量比烟梗中多,而烟梗热解产物中酚类物质含量比烟叶中多。提高热解温度有利于酮类致香物质含量产生。     

Molecular Cloning and Characteristic Features of a Novel Extracellular Tyrosinase from <Emphasis Type="Italic">Aspergillus niger</Emphasis> PA2

Biofertilizers have been widely used in many countries for their benefit to soil biological and physicochemical properties. A new microbial biofertilizer containing Phanerochaete chrysosporium and Bacillus thuringiensis was prepared to decrease nicotine content in tobacco leaves by regulating soil nitrogen supply. Soil NO₃ ^?-N, NH₄ ⁺-N, nitrogen supply-related enzyme activities, and nitrogen accumulation in plant leaves throughout the growing period were investigated to explore the mechanism of nicotine reduction. The experimental results indicated that biofertilizer can reduce the nicotine content in tobacco leaves, with a maximum decrement of 16–18 % in mature upper leaves. In the meantime, the total nitrogen in mature lower and middle leaves increased with the application of biofertilizer, while an opposite result was observed in upper leaves. Protein concentration in leaves had similar fluctuation to that of total nitrogen in response to biofertilizer. NO₃ ^?-N content and nitrate reductase activity in biofertilizer-amended soil increased by 92.3 and 42.2 %, respectively, compared to those in the control, whereas the NH₄ ⁺-N and urease activity decreased by 37.8 and 29.3 %, respectively. Nitrogen uptake was improved in the early growing stage, but this phenomenon was not observed during the late growth period. Nicotine decrease is attributing to the adjustment of biofertilizer in soil nitrogen supply and its uptake in tobacco, which result in changes of nitrogen content as well as its distribution in tobacco leaves. The application of biofertilizer containing P. chrysosporium and B. thuringiensis can reduce the nicotine content and improve tobacco quality, which may provide some useful information for tobacco cultivation.     

Residue and dissipation of zinc thiazole in tobacco field ecosystem

A high-performance liquid chromatography with ultraviolet (HPLC-UV) detection method after derivatisation was developed for the first time for the novel fungicide zinc thiazole residue in tobacco samples. Field trials in two different locations were conducted to investigate the dissipation and residue of zinc thiazole in tobacco leaves and soil. The average recoveries of zinc thiazole were in the range of 82.5%–93.9% with relative standard deviations (RSDs) of 1.2%–9.1%. The zinc thiazole showed a rapid dissipation rate in fresh tobacco leaves with the half-lives of 1.1–1.6 days. The terminal residues of zinc thiazole in cured tobacco leaves and soil were 2.8–28.0 mg kg^?1and <0.05 mg kg^?1, respectively. The results could be used to establish the maximum residue limits (MRLs) and provide guidance for the scientific use of zinc thiazole in agriculture.     

直接电喷雾离子阱质谱法快速表征烟叶

建立了一种快速、简单的同时检测烟叶中多酚类和非挥发性有机酸的电喷雾离子阱质谱方法。该方法采用水溶液萃取烟叶,萃取液无需色谱柱分离提纯,直接进入质谱检测,得到烟草质谱轮廓图。采用该方法对25种不同产地、不同等级的烟叶样品进行了测量,并结合模式识别的方法,对这25种烟叶进行了聚类分析,其结果基本符合烟草专家的等级划分。最后对各类烟叶进行了统计分析,得到了表征各类烟叶的平均质谱轮廓和各特征组分对区分烟叶贡献大小。表明该方法可以用于辅助烟叶等级划分及卷烟配方设计。     

Determination and Distribution of 210Po in Tobacco Plants from Poland

The aim of this study was the determination one of the most radiotoxic elements, ²¹⁰Po in different parts of tobacco plant from Poland. Investigation revealed that polonium is non-uniformly distributed within tobacco plant. Tobacco leaves constituting about 50% of the wet mass, contain 87.1% of the total burden of ²¹⁰Po. Among the analyzed leaves about 66% of polonium is located in the oldest, over-ground part. The data obtained here indicate that ²¹⁰Po is generally taken up by tobacco from the dry or wet deposition of the radioactive fall-out onto the plant. Moreover, ²¹⁰Po concentration in tobacco leaves from Poland are higher than that in the other countries.     

Design,synthesis, bioactivity and mechanism of action of novel myricetin derivatives containing amide and hydrazide

A series of myricetin derivatives containing amide and hydrazide were designed and synthesized. All the compounds were characterized by NMR and HRMS. Bioactivity test showed that some of the target compounds had excellent anti-tobacco mosaic virus (TMV) activity. In particular, the median effective concentration (EC₅₀) values of the anti-TMV curative and protective activities of N-(2-(2-(2-((5,7-dimethoxy-4-oxo-2-(3,4,5-trimethoxyphenyl)-4H-chromen-3-yl)oxy)acetyl)hydrazineyl)-2-oxoethyl)-4-(trifluoromethyl)benzamide (G9) were 202.3 and 164.0 μg/mL respectively, superior to ningnanmycin (329.1, 230.3 μg/mL). Microscale thermophoresis (MST) and molecular docking showed that G9 had an excellent binding affinity with tobacco mosaic virus coat protein (TMV-CP) (K_d = 0.158 ± 0.024 μM), which was better than that of ningnanmycin (K_d = 2.074 ± 0.818 μM). Moreover, there were many interaction forces between G9 and the key amino acid residues of TMV-CP. The chlorophyll content and peroxidase (POD) activity of tobacco leaves treated with G9 increased significantly, indicating that G9 could improve the photosynthesis of tobacco leaves and stimulate the resistance of tobacco leaves to TMV. The insecticidal activity of G9 against Mythimna separata (M. separate) was found to be 95.2% at 200 μg/mL, which was close to bufenozide (100%). The insecticidal activity of myricetin was significantly improved after the introduction of active groups of amide and hydrazide, which could be further explored.