共查询到20条相似文献,搜索用时 171 毫秒
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顶空气相色谱法测定化妆品中15种挥发性有机溶剂残留 总被引:1,自引:0,他引:1
建立了化妆品中15种挥发性有机溶剂残留的顶空气相色谱测定方法。样品经60 ℃、30 min静态顶空后,采用气相色谱-氢火焰离子化检测器进行检测,外标法定量。加标回收试验结果表明: 15种挥发性有机溶剂残留平均回收率为62.8%~116%,相对标准偏差均小于5%。方法的检出限为0.09~0.68 mg/kg。该方法可有效克服基体干扰,一次进样可同时分离和测定化妆品中15种挥发性有机溶剂,准确灵敏,简单快速,适用于化妆品中挥发性有机溶剂残留的检测。 相似文献
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顶空气相色谱-质谱法测定玩具中的10种挥发性有机物 总被引:1,自引:0,他引:1
建立了检测玩具中10种挥发性有机物(VOC)残留量的顶空气相色谱-质谱(HS-GC-MS)方法。样品经140 ℃、45 min静态顶空后,通过DB-624色谱柱分离和质谱检测,外标法定量。该方法对于不同VOC的定量限(LOQ)均在0.66 mg/kg以下,线性范围为0.001~2.0 μg,平均回收率在79%~106%之间,相对标准偏差(RSD)在0.4%~5.6%之间。该方法具有准确灵敏、简单快速等特点,将其应用于实际玩具样品的检测取得了良好效果。 相似文献
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以2015版《化妆品安全技术规范》中规定的常见禁用及限用有毒挥发性有机溶剂为研究对象,建立了静态顶空/气相色谱-质谱法(SHS/GC-MS)同时测定化妆品中22种有毒挥发性有机溶剂(VOC)(二氯甲烷、顺式-1,2-二氯乙烯、反式-1,2-二氯乙烯、2-氯-1,3-丁二烯、三氯甲烷、1,2-二氯乙烷、苯、四氯化碳、三氯乙烯、甲苯、四氯乙烯、氯苯、乙苯、三溴甲烷、间二甲苯、对二甲苯、苯乙烯、邻二甲苯、异丙苯、1,4-二氯苯、1,2-二氯苯、六氯丁二烯)残留的检测方法。试样在80℃下30 min静态顶空,经DB-1柱分离后,采用选择离子监测模式(SIM)进行定性定量分析。优化了顶空、色谱和质谱参数,结果表明:22种VOC在0.5~50 ng/m L浓度范围内均呈良好的线性关系,相关系数均大于0.99,在1.0,2.0,5.0 ng/m L 3个浓度加标水平下的平均回收率为80.3%~102.7%,相对标准偏差(RSD,n=6)为6.4%~9.9%,检出限为0.2~5.0 ng/g。结果表明,该方法简便、灵敏、准确,具有良好的重现性和稳定性,适合于化妆品中22种VOC残留的筛查和确证检测。 相似文献
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建立了化妆品中二噁烷的同位素稀释-顶空气相色谱-质谱联用测定方法。称取2 g化妆品样品于顶空样品瓶中,加入1 g氯化钠及20 mg/L氘代二噁烷内标溶液1 mL,再加入9 mL水。密封后摇匀,置于顶空进样器中,在70℃平衡40 min。气液平衡后的上部气体经HP-5 MS石英毛细管气相色谱柱(30 m×0.25 mm×0.25μm)分离后,采用选择离子扫描模式进行质谱定性及定量分析。二噁烷的方法定量限为2.5 mg/kg;在2.5~50 mg/kg的3个添加水平范围内的平均回收率为90.5%~104.0%,相对标准偏差为1.26%~3.98%。本方法准确、简便、快速,能够满足化妆品样品中二噁烷残留量的检测要求。 相似文献
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Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments. 相似文献
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KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields. 相似文献
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N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
The review contains a concise historical account and information on the most significant researches undertaken by the staff
at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry
of Heterocyclic Compounds.
Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008. 相似文献
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Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields. 相似文献
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Uroš Grošelj Mojca Žorž Amalija Golobič Branko Stanovnik Jurij Svete 《Tetrahedron》2013,69(52):11092-11108
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives. 相似文献
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The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion. 相似文献
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An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions. 相似文献
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Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines. 相似文献
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Mohammed KajjoutChristian Rolando 《Tetrahedron》2011,67(25):4731-4741
Quercetin, the polyphenolic compound, which has the highest daily intake, is well known for its protective effects against aging diseases and has received a lot of attention for this reason. Both quercetin 3-O-β-d-glucuronide and quercetin 3′-O-β-d-glucuronide are human metabolites, which, together with their regioisomers, are required for biological as well as physical chemistry studies. We present here a novel synthetic route based on the sequential and selective protections of the hydroxyl functions of quercetin allowing selective glycosylation, followed by TEMPO-mediated oxidation to the glucuronide. This methodology enabled us to synthesize the five O-β-d-glucosides and four O-β-d-glucuronides of quercetin, including the major human metabolite, quercetin 3-O-β-d-glucuronide. 相似文献