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M. Kameswara Rao M. Sharma S. K. Raza D. K. Jaiswal 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):559-566
The synthetic standards for cysteine and valine adducts of sulphur mustard have been synthesized using 2-(2-chloroethylthio) ethanol (half-mustard). These adducts have been recognized as biomarkers for exposure to sulphur mustard. The adducts have been fully characterized using 1 H and 13 C NMR spectroscopy and mass spectrometric techniques. 相似文献
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固相微萃取和同时蒸馏萃取与气相色谱/质谱法分析芥末膏制品的风味成分 总被引:15,自引:0,他引:15
采用固相微萃取和同时蒸馏萃取技术分离芥末膏制品的挥发性成分,用GC/MS分析鉴定,对总离子流色谱的峰面积进行归一化定量。共鉴定了22种化学成分,占总峰面积的99%以上,其中含硫化合物8种,含氮化物3种,含氧化合物11种。最主要的成分是异硫氰酸烯丙酯,其次是丙二醇,其他主要成分还有对羟基二叔丁基甲苯、油酸、9-十六烯酸、棕榈酸、5-甲基甲氢噻吩-2酮、二烯丙基二硫化物,异硫氰酸苯乙酯等。比较了各种萃取技术对分析结果的影响,同时蒸馏萃取法不能分离出水溶性成分如丙二醇等,在固相微萃取方法中,聚二甲基硅氧烷纤维头对极性较强的成分的取样效果不理想,聚乙二醇-二乙烯苯纤维头顶空取样的萃取效果最好。 相似文献
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M.J. Tubergen R.D. Suenram A.C. Samuels M.W. Ellzy 《Journal of Molecular Spectroscopy》2005,233(2):180-188
Rotational spectra have been recorded for both the 35Cl and 37Cl isotopic forms of two structural conformations of 2-chloroethyl ethyl sulfide (CEES). The rotational constants of the 35Cl and 37Cl isotopomers were used to identify the conformational isomers. A total of 236 hyperfine transitions have been assigned for 47 rotational transitions of the 35Cl isotope of a GGT conformer, and 146 hyperfine have been assigned for 37 rotational transitions of the 37Cl isotopomer. For the second conformer, a total of 128 (110) hyperfine and 30 (28) rotational transitions have also been assigned to the 35Cl (37Cl) isotopes of a TGT conformation. The extensive hyperfine splitting data, measured to high resolution with a compact Fourier transform microwave spectrometer, were used to determine both the diagonal and off-diagonal elements of the 35Cl and 37Cl nuclear quadrupole coupling tensors in the inertial tensor principal axis system. The experimental rotational constant data, as well as the 35Cl and 37Cl nuclear quadrupole coupling tensors, were compared to the results from 27 optimized ab initio (HF/6-311++G∗∗ and MP2/6-311++G∗∗) model structures. 相似文献
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Karolin K. Kroening Douglas D. Richardson Scott Afton Joseph A. Caruso 《Analytical and bioanalytical chemistry》2009,393(8):1949-1956
Sulfur mustard (HD), bis(2-chloroethyl)sulfide, is one of a class of mustard agents which are chemical warfare agents. The
main chemical warfare hydrolysis degradation products of sulfur mustards are: thiodiglycol, bis(2-hydroxyethylthio)methane,
1,2-bis(2-hydroxyethylthio)ethane, 1,3-bis(2-hydroxyethylthio)propane, and 1,4-bis(2-hydroxyethylthio)butane. The aim of this
study is to identify these five hydrolysis degradation products utilizing reversed-phase high-performance liquid chromatography
coupled with inductively coupled plasma mass spectrometry (ICP-MS) for element-specific sulfur detection using a collision/reaction
cell and electrospray ionization mass spectrometry to confirm the identification. To date, this is the first study utilizing
ICP-MS with 32S element-specific detection for the analysis of vesicant chemical warfare agent degradation products. 相似文献
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Pot experiments were conducted to study the efficacy of a slow sulfur-releasing fertilizer, sulfur glass fritz (SGF 1), on
growth, photosynthesis, and sulfur, and nitrogen assimilation potentials of brown mustard (Brassica juncea L. Czern. & Coss. cv. Pusa Jaikisan). Growth as indicated by biomass accumulation slowed down in response to the application
of sulfur glass fritz. A similar trend was observed in the case of photosynthesis rate. The activity of two marker enzymes,
ATP-sulfurylase and nitrate reductase, showed very low levels of activity, indicating poor assimilation of sulfur and nitrogen
by the plant under sulfur glass fritz. It is therefore concluded that the release of sulfur by sulfur glass fritz is too slow
and that the initial nonavailability of sulfur to the plants could lead to suboptimization of both sulfur- and nitrogen-assimilating
enzymes. These factors may contribute to low rates of photosynthesis and poor growth. 相似文献
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芥菜多糖的研究 总被引:10,自引:0,他引:10
采用Sevag法除蛋白和乙醚除脂,再水煮-醇沉法,从芥菜中提取得到浅黄色芥菜粗多糖。苯酚-硫酸法测定总糖含量;UV法及IR法检测多糖性质;自动旋光仪测定旋光度;HPLC鉴定多糖的单糖组分及其相对百分比含量;采用凝胶渗透色谱-激光光散射联用技术(SEC-LLS)分析多糖的分子量范围及其分布。该芥菜多糖,无甜味,易溶于水,总糖含量为98.96%;192 nm处有明显吸收峰,260,280 nm处无吸收峰,证明被测物为多糖,且不含核酸及蛋白质;红外吸收光谱分析,在3 402,2 926,2 853,1 636,1 400,1 385,1 326, 1 125,757,658,619,559 cm-1处表现为典型的多糖吸收峰;旋光度为+151.5°。糖残基间的苷键可能为α-糖苷键;分子量在1.42×104~2.55×106之间,80%的组分集中在2.1×105左右;芥菜多糖主要由葡萄糖、果糖、半乳糖、阿拉伯糖和木糖组成,其摩尔比值为21.4∶12.89∶5.6∶4∶2.5。 相似文献
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含氮芥和亲脂基团的聚磷酸酯的合成及其抗肿瘤活性的初步研究 总被引:1,自引:1,他引:0
本文通过3-烷氧基1,2-丙二醇与N,N'-双(2-氯乙基)二氯磷酰胺的缩合反应,制得11种新的含氮芥和亲脂基团的聚磷酸酯.用核磁、红外光谱以及元素分析确定了聚合物的结构.部分聚合物抗肿瘤初步试验结果表明.这类聚磷酸酯对小鼠肉瘤180有一定的抑制作用.在本研究中还改进了3-烷氧基-1,2-丙二醇的合成方法. 相似文献
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Maria G. Corradini Veronique Stern Thongchai Suwonsichon Micha Peleg 《Rheologica Acta》2000,39(5):452-460
Samples of commercial tomato paste, low fat mayonnaise and mustard about 6–8 mm thick were squeezed to 0.8 mm at various
speeds between 5 mm min−1 and 25 mm min−1 between Teflon-coated parallel plates 127 mm in diameter using an Instron UTM Model 5542. All the log force vs log height
relationships had a clearly identified linear region. This indicated that a dominant squeezing flow regime was achieved at
about 3 mm height, and that the machine has the proper stiffness to perform the tests. The stress level at a pre-selected
height in this region is a measure of consistency, sensitive enough to distinguish between products of different brands. The
residual stress after relaxation for about 2 min was on order of 10–50% of the initial stress, an indication that all three
foods have a considerable structural integrity. In all three products there was a considerable discrepancy between the observed
rate effects and predictions based on a pseudoplastic (power law) model. It could be described by the empirical relation (Fv1 − FR)/(Fv2 − FR)=(V1/V2)m where Fv1 and Fv2 are the forces at the given displacement reached at speeds v1 and v2 respectively, FR is the residual force after relaxation (found to be practically rate independent), and m is a constant of the order of 0.15–0.33,
independent of the compression velocities ratio but characteristic of the food and brand. The calculated elongational viscosity
was not a unique function of biaxial strain rate. To a certain extent, this was probably due to imperfect lubrication. But
it was also a manifestation of these products considerable structural integrity which cannot be accounted for by models developed
for ideal liquids.
Received: 1 November 1999 Accepted: 2 May 2000 相似文献