共查询到19条相似文献,搜索用时 46 毫秒
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以四氯乙烯作萃取剂,以四氢呋喃为分散剂对水样中4种环境激素甲草胺、乙草胺、三唑酮和三唑醇进行分散液液微萃取。提取液用气相色谱-质谱法测定。4种环境激素的质量浓度与其相应峰面积均在0.05~100μg.L-1范围内呈线性关系。甲草胺、乙草胺、三唑酮和三唑醇的检出限(3S/N)分别为0.016,0.015,0.023,0.032μg.L-1。在0.2,2.0mg.kg-1两个添加水平下进行回收试验,4种环境激素的回收率在86.8%~118%之间,测定值的相对标准偏差(n=6)在2.1%~6.2%之间。 相似文献
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壳聚糖多孔微球负载PdCl2选择性催化氢化氯代硝基苯的研究 总被引:14,自引:1,他引:14
以壳聚糖为原料,液体石蜡为分散介质,甲醛,戊二醛为交联剂,通过反相悬浮交联制备了粒径小于100μm的壳聚糖多孔微球;对制备壳聚糖多孔微球的影响因素进行了探讨,并用FTIR和SEM表征了多孔微球;XPS表明,壳聚糖多孔微球经PdCl2负载后,PdCl2与壳聚糖形成配合物,配位键是在PdCl2的Pd与壳聚糖的N之间形成。在常温常压下,PdCl2/壳聚糖多孔微球能选择性地催化还原氯代硝基苯为氯苯胺;对影响催化加氢的因素如反应温度、溶剂、催化剂用量和底物浓度作了探讨。 相似文献
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采用两步一锅法,在聚砜(PSF)主链上键联了末端基为磺酸根基团的侧链,获得了疏水主链与磺酸根基团"微相分离"结构的磺化改性PSF。以氯乙基异氰酸酯(CEIC)为亲电试剂,使PSF主链上的苯环发生付-克烷基化反应,制得侧链含有活性基团—NCO的中间产物聚合物PSFeic;通过活性基团—NCO与对羟基苯磺酸钠(HBSAS)生成氨基甲酸酯的较快速的反应,获得了侧链末端为磺酸根基团的磺化改性聚砜PSF-sas。采用FT-IR、1 H-NMR及紫外分光光度法对目标产物聚合物PSF-sas的化学结构进行了表征。以PSF-sas为膜材,采用流延法制备了PSF阳离子交换膜,测定了交换膜的基本性能,包括离子交换容量、吸水率及质子传导率。研究结果表明,在路易斯酸催化剂作用下,CEIC与PSF主链上苯环之间的付-克烷基化反应可顺利进行,生成中间聚合物产物PSF-eic;以强极性的二甲基乙酰胺(DMAC)为溶剂,反应24h,PSF-eic分子链中乙基异氰酸酯(eic)的键合量可达2.43mmol/g。在此基础上进行第2步反应,可得到磺酸根基团含量为2.23mmol/g的目标产物PSF-sas,所制备的阳离子交换膜,具有高的离子交换容量,适当的吸水率与高的质子传导率。 相似文献
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相分离聚合法:(Ⅰ)羧酸型共聚功能微球的合成 总被引:1,自引:0,他引:1
Crosslinked functional microspheres with Carboxylic group have been synthesized by the method of Phaseseparated polymerization from monomers of methacrylic acid and other vinyl-type monomers. The effects of reaction condition such as comonomer, crosslinking agent, initiator and polymerization temperature, as well as polymerization time on the morphological structure of microspheres formed have been studied. The functional polymeric microspheres with good spherical form, diameter near 5 micrometers, narrow dispersion in diameter and contained carboxylic group can be synthesized stably. 相似文献
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采用悬浮聚合方法合成了多孔交联聚苯乙烯微球,研究发现微球的粒径与分散剂含量、水油比、搅拌速度和成孔剂有关,而微球的孔径与成孔剂的种类和含量有关。 增加分散剂的用量,提高水油比和加快搅拌速度都能导致微球的粒径减小。 微球的孔径和粒径均随着成孔剂与聚合物溶度参数差值变大而增加。通过改变以上条件得到粒径为100~300 μm和孔径为8~36 nm的交联度为27%的多孔交联聚苯乙烯微球,并利用光学显微镜、场发射扫描电子显微镜(SEM)和氮气吸附解吸法对微球进行了相应的表征。 得到的微球在固相合成载体中有一定的应用前景。 相似文献
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双酚A型环氧树脂多孔微球 总被引:6,自引:0,他引:6
双酚A型环氧树脂多孔微球杨振忠许元泽俞浩赵得禄(中国科学院化学研究所高分子物理开放实验室北京100080)关键词多孔微球,双酚A环氧树脂,相反转技术微米级高分子多孔微球在生物医学、电子、印刷、信息业等方面具有重要作用.然而,通常的乳液聚合,悬浮聚合... 相似文献
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环境内分泌干扰物对人体健康和生态环境具有严重危害,发展高效的环境内分泌干扰物检测方法与去除技术具有重要意义。由于拥有高度的吸附选择性、较大的吸附容量和良好的可重复利用性,分子印迹聚合物在环境内分泌干扰物的检测与去除方面得到了诸多应用。本文介绍了分子印迹聚合物的制备方法及性能特点,综述了近年来基于分子印迹聚合物的固相萃取技术和传感器技术在环境内分泌干扰物的灵敏、特异性检测中的应用,以及基于分子印迹聚合物的吸附技术与其他方法的联用技术用于环境内分泌干扰物的选择性高效去除,并分析了分子印迹聚合物在合成和使用方面存在的问题,展望了其应用前景。 相似文献
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综述了环境内分泌干扰物中农药抗原、抗体制备技术、放射免疫、酶免疫、荧光免疫、化学发光免疫技术和免疫传感器现状及其免疫分析研究发展趋势. 相似文献
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《Analytical letters》2012,45(8):1355-1366
A rapid and efficient sample preparation method, which is called microwave-assisted microsolid phase extraction, was developed for the determination of endocrine disrupting chemicals in atmospheric particulate matter. The endocrine disrupting chemicals included bisphenol A, diethyl phthalate, dibutyl phthalate, and di(2-ethylhexyl) phthalate. The endocrine disrupting chemicals were isolated by microwave-assisted extraction following adsorption by copper(II) isonicotinate using microsolid phase extraction. The endocrine disrupting chemicals were subsequently determined by high performance liquid chromatography with an ultraviolet detector. The extraction was optimized for temperature, time, desorption time, and desorption solvent. Limits of detection (in the range of 2.0–8.5 nanograms per liter), limits of quantification (in the range of 6.6–28.0 nanograms per liter), and repeatability of the procedure (less than 10 percent) were established. Diethyl phthalate, diethyl phthalate, and di(2-ethylhexyl) phthalate were determined at values from 0.57 to 68.8 nanograms per cubic meter in atmospheric particulate matter collected from an urban area, a business center, and an industrial site in Dongguan, China. The concentration of bisphenol A was below the detection limit in these samples. 相似文献
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Xian Li Wu Shijie Song Xiao Hu Lan Li Sufang 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2018,92(12):2535-2541
Russian Journal of Physical Chemistry A - Two type of hollow graphene microspheres were investigated for the adsorption performance of gaseous formaldehyde. Hollow gently reduced graphene oxide... 相似文献
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An analytical method for the simultaneous determination of bisphenol A, 4-t-octylphenol, 4-n-octylphenol, and 4-n-nonylphenol in cosmetic samples has been developed. These compounds have toxic effects on human health as they have shown to produce endocrine disrupting properties. Therefore, their presence in cosmetics should be avoided according to the current European Regulations on cosmetic products. The method is based on high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS) detection. Standard addition calibration was used to avoid matrix effects. The limits of detection values ranged between 7 and 15?ng?mL?1 (threefold of the residual standard deviation of regression lines). The proposed method was validated, and good recovery (90–106%) and repeatability values (2.7–8.2%) were obtained. Finally, the method was successfully applied to ten commercially available cosmetic samples. The good analytical features of the proposed method make it useful to carry out the quality control of cosmetic products and raw materials to assure the safety of users. 相似文献
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Li Dong Chen Xiaolong Ma Jie Shao Qinsi Li Aijun Yan Wei Zhang Jiujun 《Russian Journal of Electrochemistry》2019,55(11):1098-1109
Russian Journal of Electrochemistry - Nitrogen-doped hierarchical porous hollow carbon microspheres (N-HPHCS) are synthesized using melamine-formaldehyde (MF) resin as carbon and nitrogen sources,... 相似文献
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《Analytical letters》2012,45(4):710-725
Using single-drop microextraction followed by high performance liquid chromatography, an effective method for the rapid extraction for endocrine disruptors, including estrogens and alkylphenols, was developed. Factors that influenced the extraction efficiency, such as hydrogen bonding, hydrophobic property, polarity, and van der Waals forces, were evaluated in detail. The results indicated that bisphenol A and estrogens were extracted effectively by the solvents with hydrogen bond acceptors and higher polarity; alkylphenols preferred solvents that could supply strong van der Waals forces or possessed π-π stacking structures and superior hydrophobicity. The optimum extraction conditions were determined, including extraction time, pH, and salt effects. Under the optimized conditions, high extraction factors (≥147) were achieved. Limits of detection for the endocrine disruptors were between 0.33 and 0.67 µg L?1. The method strategy is well suited for the determination of trace levels of endocrine disruptors in environmental water. 相似文献