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icewolf7388

木虫 (小有名气)

[交流] 【求助】求助:水分测定!!!

USP标准中,水分测定项:The test preparation being prepared as directed for a hygroscopic  specimen. 怎么理解这句话?

      谢谢!
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mrzouhao

木虫之王 (文坛精英)

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junjun517(金币+2):谢谢参与 2010-08-19 08:43:24
icewolf7388(金币+3): 2010-08-19 16:14:45
请参考usp以下论述
Where the monograph specifies that the specimen under test is hygroscopic, use a dry syringe to inject an appropriate volume of methanol, or other suitable solvent, accurately measured, into a tared container, and shake to dissolve the specimen. Using the same syringe, remove the solution from the container and transfer it to a titration vessel prepared as directed for Procedure. Repeat the procedure with a second portion of methanol, or other suitable solvent, accurately measured, add this washing to the titration vessel, and immediately titrate. Determine the water content, in mg, of a portion of solvent of the same total volume as that used to dissolve the specimen and to wash the container and syringe, as directed for Standardization of Water Solution for Residual Titrations, and subtract this value from the water content, in mg, obtained in the titration of the specimen under test. Dry the container and its closure at 100 for 3 hours, allow to cool in a desiccator, and weigh. Determine the weight of specimen tested from the difference in weight from the initial weight 4of the container.
当各论指明样品在测试条件下具有引湿性时,使用一个干燥的注射器注入合适体积的甲醇或其他合适的溶剂,准确测量,至一个去了皮重的容器中,振摇使样品溶解。使用同一注射器,从容器中移取溶液转移至按规程准备的滴定容器中。用第二部分的甲醇或其他合适的溶剂重复上述操作,准确测量,将这一部分洗涤物加至滴定容器中,立即滴定。如回滴定法水试剂的标定所示,测定与溶解样品和清洗容器与注射器相同体积的的溶剂的水的含量,以mg计,然后从待测样品滴定获得的水的含量中扣除掉这部分值,以mg计。在100℃,干燥容器和它的塞子3小时,干燥器中放冷,称重。与容器初始的重量的差值就是测试样品的重量。
4楼2010-08-19 08:11:56
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icewolf7388

木虫 (小有名气)

junjun517:专业版禁止灌水顶贴 2010-08-18 16:20:57
  自己顶一下!!!
2楼2010-08-18 15:26:05
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wjy82

木虫 (著名写手)


koria0727(金币+1):多谢参与。 2010-08-19 07:36:51
icewolf7388(金币+1): 2010-08-19 16:14:33
测试准备工作正在准备为一吸湿标本指示
3楼2010-08-19 07:30:49
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桑桑sunshine

银虫 (初入文坛)

icewolf7388(金币+1): 2010-08-19 16:14:51
可翻译为:为一吸湿样品的测定准备工作
Hellen young
5楼2010-08-19 09:12:31
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