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养蚕区桑叶样品中的氟含量测定 总被引:1,自引:0,他引:1
介绍了运用氟离子选择电极法测定桑叶中的氟含量.方法的回归方程为y=63.2lgx-273.2,r=0.9996.通过对不同采样点样品的快速测定,及时了解桑叶中氟污染的现状,为管理部门能及时作出相应整治措施提供科学依据. 相似文献
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国家标准GB 1872-80对磷矿中氟含量测定分析方法有:硝酸钍容量法与氟离子选择电极法两种。笔者经过多年的工作经验认为,选用氟离子电极法操作简便、快速,仅50 min即可完成测定,准确度、精密度较好,符合中控的要求。1氟离子选择电极法实验1.1实验原理称取经研磨与烘干的试样0.1~0.2g(±0.0001 g),用盐酸分解,用柠檬酸三钠和盐酸溶液调节溶液pH=5.5~6.0。使用电位测量仪以饱和甘汞电极为参比电极,氟离子选择电极为指示电极,测得试液的电位值后,再加入标准氟溶液测得电位值,得到两个电位值的差,经计算可求出试样氟的含量。1.2仪器和试剂1)… 相似文献
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氟的测定方法主要有茜素铜比色法、硝酸钍容量法及氟离子选择电极法。前两种方法虽然准确度高,但消耗试剂多,费时,且硝酸钍有放射污染而很少使用。离子选择电极法具有操作简便、响应速度快等特点,适用批量样品测定。 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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利用超声波-氟离子选择性电极法对红茶、绿茶两种茶叶中氟含量进行测定,并对影响测定结果的一些因素进行了研究。结果红茶、绿茶中氟含量分别为120.70、106.57 mg/kg,该测定方法的加标回收率为93.50%~109.60%。结果表明超声波-氟离子选择性电极法操作简单,回收率高,能满足对茶叶样品的测定。 相似文献
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本文采用茜素络合酮比色法和氟离子选择电极法对饲料磷酸氢钙进行氟的测定实验对比,得出常用的氟离子选择电极法完全可以代替经典的蒸馏比色法的结论。 相似文献
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介绍湿法磷酸反应槽尾气中总酸雾、总氟含量的测试原理、取样装置、测试方法和结果计算。通过反应槽尾气系统测试 ,可以为装置生产操作提供数据和指导 相似文献
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用氟离子选择电极对多种矿石中的氟进行了测定,其测定范围在0.005%~x%.研究表明,用本方法测定多种矿石中氟含量精密度好,回收率在94.0%~103.2%,方法简便.此方法已应用于实际工作中. 相似文献
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An attempt is made to change the electrode properties of alkali silicate glasses containing various glass-formers and modifiers by introducing fluorine components into their compositions. Model systems with the initial hydrogen and metallic electrode functions are investigated. The study is based on the assumption that new ionogenic structural units with a mixed-anion constituent are formed in the glass structure. Lithium, sodium, and potassium silicate glasses with different fluorine contents are synthesized. Their potentiometric properties are studied. It is shown that the introduction of fluorine exerts the strongest effect on the electrode properties of alkali aluminosilicate glasses. An indirect corroboration is obtained for the assumption that strongly acid groupings containing fluorine can be formed in the glass network. It is found that the technological properties of the electrode glasses are significantly improved and the chemical durability in the potassium-containing system also becomes much higher. From the results obtained, the inference is drawn about the prospects of fluorine introduction into electrode glasses. 相似文献
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A rapid analytical method has been developed for the determination of fluorine in coal. Coal is mixed with quartz sand, then burnt and hydrolysed in steam and oxygen at 1100 °C, whereupon the different forms of fluoride in coal become solubilized. The fluorine is determined with a fluoride-ion selective electrode. The method proposed is not affected by the ash content of the coal. The obtained solution has a simple ion composition and a low blank value giving the method potential as a fluorine determination technique. A series of typical coals have been tested and the agreement between the proposed method and the ASTM method and alkali-fusion method is satisfactory. Two sedimentary rock standards have been analysed and the results are within permissible limits of error. The method is considered to be accurate and reliable, and is first compared with the half-fusion method. 相似文献