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磺化技术在生产皮革加脂剂中的应用 总被引:12,自引:1,他引:11
对磺化剂的种类、常见的磺化方法及磺化反应的工艺条件作了简要的介绍,并列举了用SO3/空气磺化和用发烟硫酸磺化制备皮革加脂剂的实例。 相似文献
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本研究探索了磺化还原氧化石墨烯的制备及其对碱性染料的吸附性能。通过接枝含有芳香自由基的磺酸根到还原氧化石墨烯(rGO)来制备磺化还原氧化石墨烯(S-rGO)纳米片材。通过红外光谱、X射线光电子能谱和扫描电镜对合成的吸附剂磺化还原氧化石墨烯(S-rGO)进行了表征,结果表明磺酸根被成功地接枝到氧化石墨烯上。本研究系统地研究了p H、时间和吸附剂量等对吸附行为的影响。吸附实验结果表明,吸附过程遵从准二级动力学模型和Langmuir模型,表明该吸附由表面反应过程所控制,属于单分子层吸附。吸附解吸实验中碱性橙21、硫黄素T和罗丹明B的吸附率均大于99%,解析率分别达到98.81%、86.63%和94.44%,表明吸附剂S-r GO对碱性染料有很好的吸附解吸性能且可重复使用。使用该材料处理工业废水可防止有害染料污染农产品后在食物链中地不断富集,从而危害人类健康。 相似文献
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采用己酸和正丁醇为原料,磺化硅胶为催化剂,非均相酯化反应合成葡萄酒香料己酸正丁酯,考察了原料配比、反应时间及催化剂用量等对酯化反应的影响。实验结果表明,磺化硅胶具有较高的催化活性,其最佳工艺条件为:n(正丁醇)∶n(己酸)=3∶1,催化剂用量为己酸质量的1.5%,回流反应3h,酯化率达96.1%;而且磺化硅胶具有较好的重复使用性能,使用5次后,酯化率仍达91.2%,磺化硅胶易于和产物分离,回收使用效果好,对设备腐蚀和环境污染都较轻。 相似文献
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首次对O3/H2O2氧化降解木质素产物进行改性研究,测定了不同氧化反应条件下的碱木质素磺化改性后的物化性能.在O3用量5%、温度20℃、pH值11.68、H2O2的用量2.5%的氧化反应后的氧化木质素,经高温磺化后,磺酸基含量最大;此时,木质素产品的表面活性也较好;在H2O2用量为10%、pH值7.08、温度20℃、O3用量5%的O3/H2O2氧化反应条件下,氧化木质素经过高温磺化后,分散性能大大改善. 相似文献
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麦草碱木素和松木硫酸盐木素磺化反应的比较研究 总被引:10,自引:0,他引:10
本文采用化学法和光谱法对麦草碱木素和松木硫酸盐木素的化学结构进行了研究,并且比较了两种木素在磺甲基化反应和高温磺化反应中的反应特性。结果表明两种木素在磺甲基化反应中反应速度和可达到的最大磺化度有显著的差别,而在高温磺化反应中差别不大。两种木素在不同的磺化反应中的差异是由本身的化学结构的不同引起的。本文还研究了磺化木素产品的物理化学性质。值得注意的是,在相同的磺化度下麦草磺化木素具有比松木更低的表面张力,并且能制得水溶性很好的木素产品,具有广阔的前景。 相似文献
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目的建立分光光度法和高效液相色谱法测定啤酒中残留直链烷基苯磺酸钠的分析方法。方法确定实验过程主要参数。制作吸光度浓度工作曲线,定量样品检测结果。采用液液萃取法提取样品中的直链烷基苯磺酸钠,在最佳色谱条件下,制作了阴离子表面活性剂(以十二烷基苯磺酸钠计)标准曲线,采用峰高外标法定量样品检测结果。结果通过实验验证亚甲蓝活性物质(methylene-blue active substances,MBAS)的特征吸收波长为652 nm,表观摩尔吸光系数ε=1.93×10~6 L/(mol·cm),检出限为4.04×10~(-3)mg/L,检测方法回收率73.4%~104.5%,相对标准偏差3.04%,线性范围为4.04×10~(-3)~2.0 mg/L。在确定的最佳实验条件下检测了6份啤酒样品,其中直链烷基苯磺酸钠残留量在0.024~0.036 mg/L之间。高效液相色谱法的线性范围是2.0~200 mg/L,检出限为2.05×10~(-3) mg/L,回收率为78.6%~98.5%,相对标准偏差≤8.9%。在确定的最佳色谱条件下检测了6个样品,测得啤酒中直链烷基苯磺酸钠的残留量在0.014~0.022 mg/L之间。结论液液萃取高效液相色谱法检测结果的准确度略高于分光光度法,但不宜在低浓度(2 mg/L)下作标准曲线。对啤酒中残留直链烷基苯磺酸钠的直接快速检测宜选取分光光度法,而准确检测则优先选用液液萃取高效液相色谱法。 相似文献
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Results are presented for the determination of levels of Ca, Cd, Ni, Cr, Cu, Pb, Mn, Zn Fe, Co and Mg in candies and chocolates consumed in southern Nigeria. Mean concentrations of metals in both confectionaries ranged 7.7–1405.2?µg/g1 for Ca, <0.001–0.2?µg/g for Cd, 1.4–7.9?µg/g for Ni, 0.4–3.0?µg/g for Cr, <0.08–2.3?µg/g for Pb, 0.4–12.6?µg/g for Mn, 0.6–8.0?µg/g for Zn, 1.7–12.3?µg/g for Fe, <0.05–1.49?µg/g for Co, and 8.4–576.1µg/g for Mg. The data showed that that these metals are not present at harmful levels. Concentrations of nickel and chromium were slightly elevated but were comparable to levels reported in similar food items elsewhere in the world. 相似文献
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Cadmium concentrations were determined in 480 liver samples from 10 different pig genetic lines produced in Vojvodina (Serbia). Cadmium levels were determined by flame atomic absorption spectrometry after mineralization by dry ashing. The difference in cadmium levels in analysed liver tissues was not significant (p?>?0.05) between the various genetic lines. However, large variations in cadmium levels (from 0.03 to 0.27?mg/kg) in liver tissues indicated its availability in the local agricultural environment in Vojvodina. The average level of cadmium (0.13?mg/kg) was higher than the levels reported in pork liver from some developed countries. 相似文献
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N. Waegeneers J.-C. Pizzolon M. Hoenig L. De Temmerman 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2013,30(9):1239-1248
The effect of animal age on concentrations of cadmium, lead, arsenic, copper and zinc in bovine tissues (meat, kidney and liver) sampled from animals reared in contaminated areas or reference regions in Belgium was investigated. For cadmium concentrations in meat samples analysis of variance (ANOVA) showed an increasing trend with age. In addition, a significant positive linear relation (p < 0.05) was found between animal age and renal (R 2 = 0.56) or hepatic (R 2 = 0.39) cadmium levels. Lead concentrations in kidneys and liver also increased with age, but the effect was blurred, likely due to the internal remobilization of lead. For the other trace elements (arsenic, copper, zinc) no relationship could be found between their concentration in meat, kidneys or liver and animal age. Renal cadmium concentrations were predicted for bovines at different ages by using the slope of the linear regression equation, and by taking into account its 95% confidence interval. Calculations for 2-year-old animals from reference areas showed that in this group the European maximum level of 1 mg kg?1 for cadmium in kidneys would be exceeded in zero to 5% of cases. If a general rejection percentage of maximum 5% would be desirable for kidneys sampled in the reference areas (according to the ALARA principle–‘as low as reasonably achievable’–of European Union policy), then (1) kidneys from animals older than 2 years from the reference areas should a priori not be considered suitable to be placed on the market, or (2) the maximum level for cadmium in kidneys should be increased to 3 mg kg?1. The latter would bear negligible risks for the general population and the majority of high-level kidney consumers. On the other hand, bovine kidneys from the most contaminated areas are not suitable to be brought into the food chain because it is predicted that the maximum level is already exceeded by more than 5% of the 1-year-old animals. 相似文献
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Y. Saavedra A. González J. Blanco 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2013,30(11):1339-1344
This paper studied the anatomical distribution of mercury (Hg), cadmium (Cd), lead (Pb), chromium (Cr), nickel (Ni), arsenic (As), silver (Ag), copper (Cu) and zinc (Zn) in the scallop Pecten maximus and the possible implications in terms of shellfish management. Six organs were analysed: mantle, gills, foot, digestive gland, kidney and gonad. On the basis of their anatomical distribution, two groups of metals were able to be distinguished: the first included Pb, Hg, Ni, Zn and Ag; and the second comprised the four other metals studied. The metals in the first group preferentially accumulated in the kidney (except for Pb), with generally much lower concentrations in the other organs. The metals in the second group accumulated mainly in the digestive gland. As and Cu were included in the second group, but they also had particular inter-organ distribution characteristics. Among the edible organs of the scallop only the adductor muscle contained important proportions of one metal, As (which is very likely accumulated as a non-toxic derivative). A selective evisceration of the metal rich non-edible organs may therefore be considered a reliable measure to be taken with a view to reduce the metal content of scallops used for human consumption. This could be especially relevant for Cd, which is accumulated in high concentrations in the digestive gland. 相似文献
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郑家明 《食品与生物技术学报》2000,19(4):376-380
首先从结构相角度探讨组织与绸重的理论关系 ,得出组织是影响绸重的重要因素这一结论 .进而 ,利用正交试验设计法安排不同指标的真丝重磅织物进行织造 ,并以绸重为指标 ,运用多元线性回归法将其与规格参数进行回归分析 ,分别建立单层、重纬、双层组织的真丝重磅织物绸重与组织的定量关系 . 相似文献
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Methylmercury intake for adult males of twelve provinces in China was estimated by means of the 2007 Chinese Total Diet Study. Methylmercury levels were measured in twelve food groups of each province of four regions and was only found in the aquatic food groups. The range for methylmercury contents of aquatic foods was 3.29–31.60?µg?kg?1, being 50–87% of total mercury. Methylmercury intakes from aquatic foods for adult males of twelve provinces ranged from 0.003 to 0.138?µg?kg?1?bw?week?1 with average of 0.041?µg?kg?1?bw?week?1, which were estimated according to methylmercury contents and corresponding aquatic food consumption. Methylmercury intakes for the Chinese population were far below the corresponding provisional tolerable weekly intake (PTWI), which was established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Consequently, there was little health risk from methylmercury exposure for the average Chinese population. 相似文献