主题：【资料】部分美国药典中文翻译——干燥失重

干燥失重(美国药典)

本章中给出的方法阐述了在特定的条件下任何物质中的挥发性组分的检测，本方法只包括挥发性成分的检测（包括水）。水分检测可用本方法，也可以同其他文献规定的方法检测。

混合后准确称量1－2克的待测样品（也可按单独文献中要求的称量）。如果样品的是比较大的晶体，需要用高速粉碎机粉碎到约2mm左右的颗粒，方可进行检测。用该样品的干燥失重的检测条件下干燥称量杯、杯盖，约30分钟恒重后方可进行称量，先准确称量称量杯（带杯盖）的重量，然后往称量杯中加入样品，带上盖，准确称量加样后的重量。轻轻地把称量杯中地样品侧振，直至称量杯中的样品高度低于5mm，对于比较松散的、体积大的也不应超过10mm高。把盛有样品称量杯放置在干燥器内，打开杯盖，放置在干燥室内。样品的干燥温度和干燥时间应根据文献。[注意：文献中报道的干燥温度应该被视为±2℃的一个温度范围。]打开干燥室，迅速盖上杯盖，可以在干燥室中降温到室温，然后称量。

如果待测样品在低于干燥使用的检测温度时就发生了溶解现象，可以在温度在低于溶解温度（上述）5-10℃下，维持1－2小时，然后在升温到指定温度。

检测样品是胶囊，检测样品应该从至少是4个胶囊内容物的混合样中取出。
检测样品是片剂，应至少压碎4个片的粉末，从中取出优良粉末用于检测。
要是按着单独的文献报道作干燥失重的检测，应该使用在这些文献中要求采用的热重量分析仪和高灵敏天平。
要是按着单独文献报道中做真空干燥失重，应该使用这些文献中要求采用的真空干燥器、真空干燥枪或者其他的真空干燥设备。
按规定干燥器做干燥实验，应该特别仔细以确定干燥器能保持全效工作。
在采用单独文献报道的毛细管真空干燥失重法实验中，应该使用直径为225±25um的带塞毛细管，维持干燥室内的压力在5毫米汞柱或者更低。在加热结束时，可以把干燥的空气放进干燥室内，盖上塞，把毛细管在干燥室内冷后，称重。

建议这类短文直接帖出来。

我是想直接贴出来，那天我是在网吧，根本就没有PDF文件的阅读功能。

<731> LOSS ON DRYING
    The procedure set forth in this chapter determines the amount of volatile matter of any kind that is driven off under the conditions specified. For substances appearing to contain water as the only volatile constituent, the procedure given in the chapter, Water Determination  921 , is appropriate, and is specified in the individual monograph.

    Mix and accurately weigh the substance to be tested, and, unless otherwise directed in the individual monograph, conduct the determination on 1 to 2 g. If the test specimen is in the form of large crystals, reduce the particle size to about 2 mm by quickly crushing. Tare a glass-stoppered, shallow weighing bottle that has been dried for 30 minutes under the same conditions to be employed in the determination. Put the test specimen in the bottle, replace the cover, and accurately weigh the bottle and the contents. By gentle, sidewise shaking, distribute the test specimen as evenly as practicable to a depth of about 5 mm generally, and not more than 10 mm in the case of bulky materials. Place the loaded bottle in the drying chamber, removing the stopper and leaving it also in the chamber. Dry the test specimen at the temperature and for the time specified in the monograph. [NOTE—The temperature specified in the monograph is to be regarded as being within the range of ±2  of the stated figure.] Upon opening the chamber, close the bottle promptly, and allow it to come to room temperature in a desiccator before weighing.

    If the substance melts at a lower temperature than that specified for the determination of Loss on drying, maintain the bottle with its contents for 1 to 2 hours at a temperature 5  to 10  below the melting temperature, then dry at the specified temperature.

    Where the specimen under test is Capsules, use a portion of the mixed contents of not fewer than 4 capsules.

    Where the specimen under test is Tablets, use powder from not fewer than 4 tablets ground to a fine powder.

    Where the individual monograph directs that loss on drying be determined by thermogravimetric analysis, a sensitive electrobalance is to be used.

    Where drying in vacuum over a desiccant is directed in the individual monograph, a vacuum desiccator or a vacuum drying pistol, or other suitable vacuum drying apparatus, is to be used.

    Where drying in a desiccator is specified, exercise particular care to ensure that the desiccant is kept fully effective by frequent replacement.

    Where drying in a capillary-stoppered bottle* in vacuum is directed in the individual monograph, use a bottle or tube fitted with a stopper having a 225 ± 25 µm diameter capillary, and maintain the heating chamber at a pressure of 5 mm or less of mercury. At the end of the heating period, admit dry air to the heating chamber, remove the bottle, and with the capillary stopper still in place allow it to cool in a desiccator before weighing.

帖出原文，方便对照。

Go ahead, your English is very good.

But one more question: For the drying loss, what RSD is about 4 samples?

原文由 zhaozhixin 发表:
Go ahead, your English is very good.

But one more question: For the drying loss, what RSD is about 4 samples?

if limit＜1%， one is enough.
if limit＞1%，two samples. closer is better.

对于2楼的几点勘误：

“....需要用高速粉碎机粉碎到约2mm左右的颗粒，方可进行检测。用该样品的干燥失重的检测条件下干燥称量杯、杯盖.......”

1）应该是快速研细，而不是必须为高速粉碎机；



“本章中给出的方法阐述了在特定的条件下任何物质中的挥发性组分的检测，本方法只包括挥发性成分的检测（包括水）。水分检测可用本方法，也可以同其他文献规定的方法检测。”

2）此处“也可以同其他文献规定的方法检测。”原文的意思是用<921>水分检查法，而不是其他文献规定的方法。

如果待测样品在低于干燥使用的检测温度时就发生了溶解现象，可以在温度在低于溶解温度（上述）5-10℃下，维持1－2小时，然后在升温到指定温度。

3）应是融化或熔融，而不是溶解。

呵呵，正好今天在翻译印度公司的干燥失重材料，就来说两句。

第一段：
The procedure set forth in this chapter determines the amount of volatile matter of any kind that is driven off under the conditions specified. For substances appearing to contain water as the only volatile constituent, the procedure given in the chapter, Water Determination 921, is appropriate, and is specified in the individual monograph.
本章中给出的方法阐述了在特定的条件下任何挥发性物质的检测。<921>水分检测法适用于那些似乎以水分作为唯一挥发性成分的供试品，具体规定见各论。

这里的individual monograph我觉得是指各论，因为<921>水分检测法是通用的方法，而具体到每个药品有什么规定就要看各论了，比如布洛芬就要用五氧化二磷减压干燥。这里的specify是“指定，规定”的意思。

原文由 happyjyl 发表:

第一段：
The procedure set forth in this chapter determines the amount of volatile matter of any kind that is driven off under the conditions specified. For substances appearing to contain water as the only volatile constituent, the procedure given in the chapter, Water Determination 921, is appropriate, and is specified in the individual monograph.
本章中给出的方法阐述了在特定的条件下任何物质中的挥发性组分的检测。<921>水分检测法适用于那些似乎以水分作为唯一挥发性成分的供试品，具体规定见各论。

楼上的两位给出了更恰当的翻译。

我的翻译是如下：对于水分为唯一挥发性成分的供试品，用各论项下描述的水分测定法〈921〉检测。意思与happy是一样的。

感谢楼主分享