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用DSC、扫描电镜、雾点测量仪等手段,对不同组成的甲基丙烯酸甲酯-苯乙烯无规共聚物(MS)与聚偏氟乙烯(PVF_2)共混体系的相容性进行了研完。结果表明,随着苯乙烯在MS共聚物中含量的增多,PVF_2/MS共混体系在无定形态时由相容逐渐转变为半相容体系。测定了该体系的最低临界相容温度曲线。 相似文献
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用DSC、扫描电镜、雾点测量仪等手段,对不同组成的甲基丙烯酸甲酯-苯乙烯无规共聚物(MS)与聚偏氟乙烯(PVF_2)共混体系的相容性进行了研完。结果表明,随着苯乙烯在MS共聚物中含量的增多,PVF2/MS共混体系在无定形态时由相容逐渐转变为半相容体系。测定了该体系的最低临界相容温度曲线。 相似文献
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我国环境中有机污染物分析方法及痕量富集技术的进展 总被引:1,自引:0,他引:1
对有机污染物分析在近年进展作了评述。其主要内容涉及试样的预处理技术(如顶空法,吹扫-捕集法,固相萃取,半透膜等技术),各化合物的适用及有效的分析方法或仪器(如GC,HPLC及GC/MS等)以及各种技术及方法的联用技术等(引述文献37篇)。 相似文献
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衍生化-离子阱气相色谱质谱联用检测乳粉中三聚氰胺时不同质谱检测方法研究 总被引:1,自引:0,他引:1
利用N,O-双三甲基硅基三氟乙酰胺(BSTFA)和三甲基氯硅烷(TMCS)衍生化试剂对乳粉中三聚氰胺进行衍生化处理,利用离子阱气相色谱质谱联用仪,建立了全扫描、选择离子监测、二级质谱3种测定三聚氰胺的质谱方法.选择离子监测以三聚氰胺衍生物的特征离子m/z342,327,171,99为定性离子,以m/z327为定量离子;全扫描法二级质谱特征峰为定性依据,以特征离子m/z327为定量离子;二级质谱法以衍生物二级质谱m/z285,171,213为定性离子,以m/z 285为定量离子.3种方法的线性范围为0.05~2.0 mg/L,线性相关系数分别为0.9986、0.9990、0.9988;检测限分别为0.005、0.002、0.003 mg/kg,RSD分别为6.3%、5.7%、6.1%(n=6),方法的回收率为84%~105%.3种不同质谱检测方法应用到乳粉的检测中效果良好,均能够满足乳粉中三聚氰胺的检测要求. 相似文献
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METHYL SALICYLATE FLUORESCENCE AS A PROBE OF THE GEOMETRY OF COMPLEXATION TO CYCLODEXTRINS 总被引:2,自引:0,他引:2
Abstract Methyl salicylate (MS) is found to form complexes with α-, β- and γ-cyclodextrins in aqueous solution. The fluorescence of the complexes differ dramatically from that of MS in pure aqueous solution in the case of α- and γ-cyclodextrin, but is similar to that of MS in pure aqueous solution in the case of β-cyclodextrin. The binding constants for the complexes have been evaluated and the fluorescence of the complexes has been employed to infer the geometry of the complexes. 相似文献
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酸枣果肉中挥发性化学成分分析 总被引:3,自引:0,他引:3
报道了用蒸馏-萃取法提取酸枣果肉中挥发性物质,测得酸枣果肉挥发油的含量为1.80%,用GC/MS法从酸枣果肉挥发油中分离并确定出43种化学成分。用峰面积归一化法通过化学工作站数据处理系统,得出各化学成分在挥发油中的相对百分含量。其中主要成分为酸类化合物占挥发油总量的52.26%,酚类化合物为9.34%,酯类化合物为23.05%,醛类化合物为2.77%,醚类化合物为2.66%,烷烃化合物为1.89%,其它类化合物仅占3.77%。共占酸枣果肉中挥发油总量的95.62%。 相似文献
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Water-distilled essential oil from leaves ofArbutus unedoL. of Turkish origin was analyzed by GC/MS. Thirty-seven constituents were characterized with (E)-2-decenal (12.0 %), -terpineol (8.8 %), hexadecanoic acid (5.1 %), and (E)-2-undecenal ( 4.8 %) as the major constituents. 相似文献
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GC和GC/MS分析脱硫细菌代谢二苯并噻吩的产物 总被引:1,自引:0,他引:1
从茂名炼油厂周围土壤中分离得到一株可脱除二苯并噻吩(DBT)的细菌YC-LI-1用GC/MS方法定性鉴定了该细菌脱除DBT的代谢的有机产物为2-羟基联苯(1-OHBP),此外试验还证明了DBT中的硫原子代谢为水溶性的硫酸盐,用GC方法测定了该菌种将DBT代谢为2-羟基联苯的转化率,分析结果表明该菌种可有效代谢DBT,转化率达90%以上。 相似文献
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CELLULAR DELIVERY AND RETENTION OF PHOTOFRIN: II. THE EFFECTS OF HUMAN versus MOUSE AND BOVINE SERUM
The effects of human serum (HS), mouse serum (MS) and fetal bovine serum (FBS) on cellular delivery and retention of Photofrin were examined using human lung tumor cells (A549) cultured in vitro. The results show that these three kinds of sera exhibit substantial differences in: (i) degree of inhibition of Photofrin cellular uptake, (ii) retention capacity of Photofrin delivered to the cells in their presence and (iii) efficacy of promoting the clearance of Photofrin from the cells. It is suggested that these differences originate from unequal interaction of each of the sera with Photofrin material, which in turn is the consequence of variability in composition and in the levels of serum proteins in HS, MS and FBS. The highest degree of Photofrin disaggregation and and competitive binding of its constituents was attributed to HS. The lowest degree of Photofrin disaggregation, and the competitive binding limited mostly to monomeric porphyrin forms was implicated for FBS. For MS, the spectroscopic and cellular data indicated a lesser degree of Photofrin disaggregation than with HS, with little if any consequence in Photofrin retention characteristics. The implication of this comparative analysis is that in vitro studies using FBS may underestimate the extent of interaction of Photofrin with serum proteins in humans, and overestimate the retention capacity of the photosensitizer in human tissues. Studies in vivo using a mouse model may also underestimate the degree of disaggregation of Photofrin in human circulation, and give different photosensitizer tissue retention levels than in humans. 相似文献
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H. Saglam T. Gozler B. Kivcak B. Demirci K. H. C. Baser 《Chemistry of Natural Compounds》2001,37(5):439-441
The chemical composition of the essential oil ofHaplophyllum myrtifoliumBoiss., endemic to Turkey, was examined by GC/MS. Ninety-seven compounds were characterized with linalool (12.8%), -caryophyllene (10.3 %), and methyleugenol (5.9 %) as the main constituents. 相似文献
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溶剂抽提、水蒸气蒸馏和超临界萃取用于古蓬香脂组成分析方法的比较(英文) 总被引:2,自引:0,他引:2
采用乙醇和丙酮溶剂抽提、CO2超临界萃取(SFE)以及水蒸气蒸馏(SD)的方法提取古蓬香脂乳胶。对乙醇和丙酮提取物进行了HPLC和GC-MS分析。两个提取物的HPLC谱图十分相似,总共可分离出17个组分。而乙醇提取物的GC-MS分析鉴定表明有21个组分。SFE提取物的GC-MS分析得到8个组分。SD提取物有14个组分。在超临界流体中加入甲醇无论对提取物的组分数还是对其浓度都没有什么影响。 相似文献
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采用GC/MS法检测出邻氰堪苄基氯中的杂质组分,并使用萘做内标物进行气相色谱法对邻氰堪苄基氯的定量检测。 相似文献