共查询到18条相似文献,搜索用时 734 毫秒
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氟化物是人体必须的微量元素之一,如果缺氟或过量,会给人身带来危害,比如缺氟会出现龋齿,而过量时易患氟骨病及班斑齿病。当水中氟化物含量小于0.5mg/L时视为缺氟,而超过1.0mg/L时视为氟过量。因自然界中水具有循环特质,所以氟化物含量会对水源质量造成一定程度的影响。基于此,必须重视并做好氟化物检测工作。 相似文献
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离子选择电极法测定牙膏中氟含量的研究与探讨 总被引:1,自引:0,他引:1
本文对离子选择电极法测定牙膏中氟化物进行了研究与探讨.讨论了仪器精度、共存离子引入的误差及干扰、测定的pH值范围、电极相关因素的影响、搅拌的影响和测定中应注意的问题等因素对氟离子选择电极法测定牙膏中氟化物的影响。该方法具有选择性好,准确、快速、检测范围宽的特点. 相似文献
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氟化物指含负价氟的有机或无机化合物。与其他卤素类似,氟生成单负阴离子。无机氟化物的例子有氢氟酸(HF)、氟化钠(NaF)等。本文用离子选择电极法和离子色谱法分别分析含氢氟酸(HF)溶液中的氟化物。发现溶液含有氢氟酸(HF)时分析氟化物,分析结果与p H值形成干扰,pH值越低氟化物的结果越高,而采用氢氧化钠将溶液中和成碱性条件和用碳酸钠-碳酸氢钠淋洗液体系稀释样品时,干扰最小。而含氢氟酸(HF)溶液采用离子选择电极法分析时溶液pH值偏低,H+偏高,会氟化物的浓度偏高,而溶液p H值调至中性条件时干扰最小,结果最接近真值。 相似文献
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离子选择电极法测定土壤中氟化物 总被引:1,自引:0,他引:1
文章使用NaOH作为提取剂,在高温下将土壤中氟化物转变成氟化钠,将待测液调节到适当的pH后,用氟离子选择电极测定,从而求得土壤中氟化物的含量,并讲述分析测定过程中应注意的问题,结果表明离子选择电极法能够准确测定土壤中的氟化物。 相似文献
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样品中微量氟化物的测定方法 总被引:2,自引:0,他引:2
氟是人体必需的14种微量元素之一。在一定的浓度范围内,氟化物对人体有着积极的作用,但是超出了正常浓度范围,将会影响机体健康。综述了样品中微量氟化物的测定方法及其适用性。 相似文献
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用氟离子选择电极法,对市售十几种牙膏氟化物含量进行了直接测定。回收率90.8%-109%,为牙膏中氟化物测定提供了较快速的方法。 相似文献
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通过氟离子选择电极与氟试剂法对比,得出氟离子选择电极法不适合测定经铝、铁混凝剂处理后的废水中氟离子浓度的结论。氟离子选择电极法测得的结果比氟试剂法测得的值高,且随着废水氟离子浓度增加,误差增大。 相似文献
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Rajkumar Dey Ritamay Bhunia Shamima Hussain Bibhas Ranjan Chakraborty Radhaballav Bhar 《Polymer-Plastics Technology and Engineering》2017,56(3):310-320
Nickel-doped nanocrystalline ZnO with three different Ni concentrations was incorporated in polyvinylidene fluoride thin film for obtaining free-standing flexible film by sol-gel technique. The effect of Ni–ZnO loading on the optical and microstructural properties of the Ni–ZnO/polyvinylidene fluoride composite films was studied. X-ray photoelectron spectroscopy and Raman studies were performed to characterize the bonding environment. Fluorine-terminated surface showed a strong F1?s peak located at ~695?eV arising out of C–F bonds. Existence of β phase of polyvinylidene fluoride along with the presence of ZnO nanocrystals were indicated by Raman studies. Secondary ion mass spectrometry studies indicated the distribution of Ni–ZnO particles in the polyvinylidene fluoride matrix. 相似文献
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氟离子检测方法的改进及离子色谱法的应用 总被引:6,自引:0,他引:6
传统离子选择电极法分析氟离子容易被pH、金属离子和温度等因素所干扰,这样会使数据产生极大的误差。为了避免这些缺点,离子分离理论和高效液相色谱技术被应用在氟离子的分析-离子色谱法,离子色谱作为一种先进的检测手段在氟离子分析方面表现出优秀的准确性,重现性和可靠性。 相似文献
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Luo Fang Kedar Nath Ghimire Masayuki Kuriyama Katsutoshi Inoue Kenjiro Makino 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2003,78(10):1038-1047
Although fluoride is beneficial for human beings in small quantities, it causes dental fluorosis when consumed in larger quantities over a period of time. In recent years, considerable work has been conducted for the purpose of developing new and low cost absorbents for adsorptive removal of fluoride, especially chelating resins loaded with metal ions. In the present study, several types of adsorbents with different functional groups loaded with lanthanum(III) were prepared to be used for fluoride removal from water. The optimum conditions for loading lanthanum(III) on the adsorbents and the effects of pH and initial fluoride concentration as well as shaking time and solid–liquid ratio on the removal of fluoride have been investigated. Based on these fundamental data, the removal of fluoride from actual hot spring water was also tested as a practical application by comparing the efficiency of different adsorbents for the removal of fluoride from hot spring water. The following conclusions were obtained. (1) The different chemical composition and chemical structure of the polymer matrix play the most important role in fluoride adsorption, (2) strongly acidic adsorbents are more effective on fluoride removal at neutral pH than weakly acidic adsorbents, (3) the order of fluoride removal in the neutral pH range of 4.5–8.0 by the different La(III)‐loaded adsorbents employed in the present work is as follows: 200CT resin > POJRgel > IR124resin > SOJR gel ≥ CPAgel ≥ WK11 resin. The column experiments showed that the 200CT resin loaded with lanthanum(III) at pH 6.0 can be successfully employed for the removal of fluoride ions from actual hot spring water. Copyright © 2003 Society of Chemical Industry 相似文献
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提出利用人工土壤层处理含氟废水的方案,通过饱水动态土柱实验研究了氟离子在土壤层中吸附交换规律,主要探讨了土砂质量比例、柱高、淋滤液质量浓度等参数对土柱的吸附能力和渗滤速率的影响,得出土砂比参数为3∶1;渗透厚度为40 cm的人工土壤层对氟离子具有良好的吸附效果,并在较大的氟离子质量浓度范围内均适用。 相似文献