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采用高效液相色谱法同时测定化妆品中p-甲氧基肉桂酸异戊酯、4-甲基苄亚基樟脑、水杨酸乙基己酯、甲氧基肉桂酸乙基己酯、二苯酮-3、二乙氨羟苯甲酰基苯甲酸己酯和丁基甲氧基二苯甲酰基甲烷7种防晒剂的含量。样品用甲醇提取,以ZORBAX SB-Aq色谱柱分离,流动相为V(甲醇)︰V(水)=90︰10的混合溶液,用二极管阵列检测器测定。结果表明,7种防晒剂在一定的质量浓度范围内与其峰面积的线性关系良好,回收率为92.0%~103.7%,相对标准偏差为0.57%~4.32%。 相似文献
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采用高效液相色谱二极管阵列检测器检测,Kromasil C_(18)柱分离,经流动相甲醇与纯水梯度洗脱,同时测定化妆品中p-甲氧基肉桂酸异戊酯、甲氧基肉桂酸乙基己酯、水杨酸乙基己酯、胡莫柳酯、丁基辛醇水杨酸酯和乙基己基三嗪酮等6种防晒剂。结果表明,6种防晒剂在一定的质量浓度范围内与峰面积呈良好的线性关系,方法定量限为0.5~1.25 mg/L,在低、高两个添加水平下的回收率均在98.3%~101.0%,相对标准偏差(RSD)不大于1.5%。 相似文献
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通过优化《化妆品安全技术规范》(2015年版)中21种防晒剂高效液相色谱法的流动相体系获得分离度更好的21种对照品图谱,并对市售的174批防晒类化妆品中的防晒剂进行研究。结果发现174批样品中共检出16种防晒剂,其中甲氧基肉桂酸乙基己酯的使用频率最高,为92.40%,其次为双-乙基己氧苯酚甲氧苯基三嗪和二乙氨羟苯甲酰基苯甲酸己酯,分别为50.88%和49.12%。所检防晒剂用量均未超过规定限值。其中,2.30%的化妆品标签标识防晒剂与实际检出结果不一致,且均来源于网络流通领域。因此,建议化妆品监管部门应加强对网络流通领域的防晒类化妆品的监管以及强化对化妆品标签标识的管理。此外发现新的风险点:部分产品中胡莫柳酯的含量超出欧盟消费者安全科学委员会(SCCS)最新认定的安全浓度;二氧化钛添加率较高,但缺少纳米型二氧化钛的安全标准。 相似文献
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根据使用频率选用了4-甲基苄亚基樟脑、甲氧基肉桂酸乙基己酯、奥克立林、水杨酸乙基己酯、胡莫柳酯、二甲基PABA乙基己酯、二苯酮-3、双-乙基己氧苯酚甲氧苯基三嗪、苯基苯并咪唑磺酸和丁基甲氧基二苯甲酰基甲烷等具有代表性的10种有机防晒剂,通过鸡胚绒毛尿囊膜试验和人体皮肤斑贴试验分别对每种防晒剂的刺激性进行了评价。HET-CAM实验结果表明,苯基苯并咪唑磺酸和二苯酮-3具有强刺激性,其他8种防晒剂具有中度刺激性;人体皮肤斑贴试验结果显示,苯基苯并咪唑磺酸和二苯酮-3对皮肤有不良反应,其他8种防晒剂对皮肤无不良反应。 相似文献
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研究了用甲醇-甲氢呋喃-水作为流动相,从C18柱上分离和测定羟苯甲酮-5-磺酸(MS40)水杨酸钠,水杨酸苯酯(Salol)羟苯甲酮(M40)对-二甲酸氨基苯甲酸-2-乙基己酯(6007)4-叔丁基-4-甲氧基二苯甲酸甲烷(1789)对-甲氧基肉桂酸-2-乙基己酯(MCX),水氧酸-2乙基己酯(587)等8种紫外线吸收剂的色谱条件,建立了用HPLC测定上述物质的方法,其保留时间从2.83min(M 相似文献
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研究了用甲醇-四氢呋喃-水作为流动相,从C18柱上分离和测定羟苯甲酮-5-磺酸(MS40)、水杨酸钠、水杨酸苯酯(Salol)、羟苯甲酮(M40)、对-二甲酸氨基苯甲酸-2-乙基己酯(6007)、4-叔丁基-4-甲氧基二苯甲酸甲烷(1789)、对-甲氧基肉桂酸-2-乙基己酯(MCX)、水氧酸-2-乙基己酯(587)等8种紫外线吸收剂的色谱条件,建立了用HPLC测定上述物质的方法。其保留时间从2.83min(MS40)到15.89min(587)之间,回收率为96.1%~100.6%,相关系数r≥0.9995。 相似文献
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应用气相色谱 -质谱选择离子法同时测定化妆品中 6种防晒剂 (水杨酸苯酯、水杨酸高 艹孟 酯、对羟基苯甲酮、对 -甲氧基肉桂酸 - 2 -乙基己酯、二苯甲酮、3- (4’ -甲基亚苄基 ) -樟脑 )。用甲醇为提取剂来进行超声快速提取 ,方法简单、快速、准确 ,6种防晒剂的平均回收率 (n =5 )在 94 .3- 10 6 .6 %之间 ,相对标准偏差 (n =5 )在 0 .36 - 1.72 %之间 ,最低检测限在 0 .0 1~ 0 .1ng之间 相似文献
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The transport properties of ionic liquids (ILs) are crucial properties in view of their applications in electrochem-ical devices. One of the most important advantages of ILs is that their chemical–physical properties and conse-quently their bulk performances can be well tuned by optimizing the chemical structures of their ions. This will require elucidating the structural features of the ions that fundamentally determine the characteristics of the nanostructures and the viscosities of ILs. Here we showed for the first time that the“rigidity”, the order, and the compactness of the three-dimensional ionic networks generated by the anions and the cation head groups determine the formation and the sizes of the nanostructures in the apolar domains of ILs. We also found that the properties of ionic networks are governed by the conformational flexibility and the symmetry of the anion and/or the cation head group. The thermal stability of the nanostructures of ILs was shown to be con-trolled by the sensitivity of the conformational equilibrium of the anion to the change of temperature. We showed that the viscosity of ILs is strongly related to the symmetry and the flexibility of the constitute ions rather than to the size of the nanostructures of ILs. Therefore, the characteristics of the nanostructures and the viscosities of ILs, especially the thermal stability of the nanostructures, can be fine-tuned by tailoring the symmetry and the conformational flexibility of the anion. 相似文献
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Investigation of the effects of fatty acids on the compressive strength of the concrete and the grindability of the cement 总被引:1,自引:0,他引:1
In cement industry, a great energy consumption has been observed during grinding of clinker. To reduce this consumption, some waste products have been used as grinding aids.In this investigation, the effects of sunflower oil (SO), oleic acid (OA), stearic acid (SA), myristic acid (MA) and lauric acid (LA) on the fineness and strength of the cement have been examined. These aids were added into clinker in certain ratios based on the cement clinker weight and the grinding has been done for a definite time at the same condition.All of the fatty acids used increased the fineness as compared with the cement without the grinding additives. SO and OA decreased the strength significantly, LA decreased it to a lesser extent and SA increased it definitely according to the common cement. But MA did not alter the strength of the cement as much as SA. In addition, the covering of the balls influences the grinding of cement clinker unfavourably. 相似文献
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组合凹模的应力分析是一个非常复杂的问题,对其进行精确分析是解决模具寿命的关键。本文采用有限元分析软件Ansys对转子的组合凹模进行了分析,为转子组合凹模的优化设计提供了依据。 相似文献