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21.
建立了高效液相色谱串联质谱法测定泡面桶中总壬基酚迁移量的分析方法,并对市售泡面桶中壬基酚迁移进行了风险分析与评估。优化了色谱分离条件和固相萃取条件,线性范围1~500 μg/L内线性关系良好,壬基酚的方法检出限为0.002~0.004 μg/L,对实际样品迁移液进行加标回收试验,回收率在79.8%~105.2%之间,相对标准偏差(Relative Standard Deviation,RSDs)在1.74%~9.88%之间。应用该方法对市售54批泡面桶中壬基酚总迁移量进行测定,其中45件样品的迁移液中检出了壬基酚,壬基酚含量在0.006~0.079 μg/L。根据检测结果对市售泡面桶中壬基酚的安全性进行了风险分析,壬基酚的最大每日摄入量为0.0237 μg/d,远低于壬基酚的健康指导值3 μg/d,说明市场上泡面桶相对比较安全,对人体健康存在较低风险。 相似文献
22.
目的:研究N-乙酰-半胱氨酸(N-acetyl-cysteine,NAC)对壬基酚(nonylphenol,NP)诱导的小鼠Sertoli TM4细胞氧化损伤及凋亡的干预作用。方法:以Sertoli TM4细胞为对象,实验分为对照组、NP组(20 μmol/L NP处理)、NP+NAC组(5 mmol/L NAC预处理4 h后20 μmol/L NP处理24 h)、NAC组(5 mmol/L NAC处理4 h后换正常培养基培养),采用噻唑蓝法检测细胞存活率;流式细胞术检测活性氧(reactive oxygen species,ROS)含量和细胞凋亡情况;试剂盒法检测超氧化物歧化酶(superoxide dismutase,SOD)活力、过氧化氢酶(catalase,CAT)活力、丙二醛(malondialdehyde,MDA)含量及Caspase-3相对活力;Western blot法检测细胞外信号调节激酶(extracellular signal-regulated kinase,ERK)和c-Jun氨基末端激酶(c-Jun N-terminal kinase,JNK)磷酸化情况。结果:与对照组相比,20 μmol/L NP处理24 h能显著降低细胞存活率(P<0.05),同时诱导细胞内ROS生成,下调SOD和CAT活力,增加MDA含量,诱导Sertoli TM4细胞凋亡,增加Caspase-3相对活力,促进ERK、JNK蛋白磷酸化激活;与NP组相比,NAC预处理能够明显削弱NP引起的细胞内ROS生成,使SOD、CAT活力下调,MDA含量增加,Sertoli TM4细胞凋亡,Caspase-3相对活力增强,激活ERK、JNK信号通路。结论:NAC具有干预NP对小鼠Sertoli TM4细胞损伤的作用,这可能与NAC抑制NP诱导的细胞氧化应激和凋亡以及阻断ERK、JNK信号通路的激活相关。 相似文献
23.
新型Gemini型阳离子沥青乳化剂的合成与性能测试 总被引:1,自引:0,他引:1
以壬基酚和甲醛为原料经缩合反应制备出中间体双(2-羟基-5-壬基苯基)甲烷,并与环氧氯丙烷和三乙胺反应,合成出一种新型Gemini型阳离子沥青乳化剂双[5-壬基-2-((2′-羟基 3′-三乙基氯化铵)丙氧基苯基)]甲烷.详细研究了合成条件对反应的影响,得出了合成最佳工艺条件.用该乳化剂对道路沥青进行了乳化效果考察,表明该乳化剂乳化性能良好.该乳化剂合成工艺简单,是一种比较有发展前途的阳离子中裂沥青乳化剂. 相似文献
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Yasuji Okai Kiyoka Higashi‐Okai 《Journal of the science of food and agriculture》2001,81(15):1443-1446
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28.
Xin Liu Takeshi Ohta Takeshi Kawabata Fusako Kawai 《International journal of molecular sciences》2013,14(1):1218-1231
Ethoxy (EO) chain nonylphenol dehydrogenase (NPEO-DH) from Ensifer sp. AS08 and EO chain octylphenol dehydrogenase from Pseudomonas putida share common molecular characteristics with polyethylene glycol (PEG) dehydrogenases (PEG-DH) and comprise a PEG-DH subgroup in the family of glucose-methanol-choline (GMC) oxidoreductases that includes glucose/alcohol oxidase and glucose/choline dehydrogenase. Three-dimensional (3D) molecular modeling suggested that differences in the size, secondary structure and hydropathy in the active site caused differences in their substrate specificities toward EO chain alkylphenols and free PEGs. Based on 3D molecular modeling, site-directed mutagenesis was utilized to introduce mutations into potential catalytic residues of NPEO-DH. From steady state and rapid kinetic characterization of wild type and mutant NPEO-DHs, we can conclude that His465 and Asn507 are directly involved in the catalysis. Asn507 mediates the transfer of proton from a substrate to FAD and His465 transfers the same proton from the reduced flavin to an electron acceptor. 相似文献
29.
Alkylphenol ethoxylates in the environment 总被引:21,自引:0,他引:21
Carter G. Naylor James P. Mieure William J. Adams John A. Weeks Frank J. Castaldi Larry D. Ogle Robert R. Romano 《Journal of the American Oil Chemists' Society》1992,69(7):695-703
A comprehensive monitoring study, sponsored by the Chemical Manufacturers Association and designed in cooperation with the
Environmental Protection Agency (EPA), measured the levels of nonylphenol (NP) and its ethoxylates (NPE) in 30 rivers. The
sites, all receiving municipal or industrial wastewater, were selected at random from EPA’s United States river reach database
by a statistical procedure. Water column and bottom sediment samples were collected along a perpendicular transect at each
site. All samples were assayed for NP and NPE1, and the higher ethoxylates (NPE2 to NPE17) were determined in the water samples. Analysis was by high-performance liquid chromatography (HPLC) with fluorescence detection
of microgram quantities of NPE obtained by extractive steam distillation (NP and NPE1) or a dualcolumn extraction procedure (NPE2 to NPE17). Sample collection and analytical procedures were validated according to rigorous EPA guidelines, and quality assurance
standards were met throughout the study. NP and NPE concentrations in river water were mostly (60 to 75% of the samples) below
their detection limits (about 0.1 ppb for NP, NPE1, and NPE2; 1.6 ppb for NPE3–17). The highest levels found were about 1 ppb for NP, NPE1, and NPE2, 15 ppb for NPE3–17. A majority of sediment samples contained detectable amounts of NP and NPE1, ranging up to 3000 ppb for NP and 170 ppb for NPE1. Sediment interstitial water concentrations of NP were estimated to be similar to concentrations in the water column.
A portion of this paper was presented at the 1991 Annual AOCS Meeting in Chicago 相似文献
30.
详细论述了仲醇乙氧基化物(SAE)的生产工艺,并说明了其化学特性及物理性质。义中还将SAE的性能与非离子表面活性剂伯醇乙氧基化物(PAE)、壬基酚乙氧基化物(NPE)阴离子表面活性剂十二烷基苯磺酸盐(LAS)进行了比较。对仲醇乙氧基化物在家庭及工业领域内的应用做了介绍。 相似文献