24小时热门版块排行榜    

北京石油化工学院2026年研究生招生接收调剂公告
查看: 256  |  回复: 0
当前主题已经存档。

zhangxiaohang

木虫 (小有名气)

[交流] 微粉硅胶英国药典

Colloidal Silicon Dioxide


SiO2 60.08

Silica.
Silica [7631-86-9].


» Colloidal Silicon Dioxide is a submicroscopic fumed silica prepared by the vapor-phase hydrolysis of a silicon compound. When ignited at 1000° for 2 hours, it contains not less than 99.0 percent and not more than 100.5 percent of SiO2.

Packaging and storage— Preserve in well-closed containers.

Identification—

A: Transfer about 5 mg to a platinum crucible, and mix with about 200 mg of anhydrous potassium carbonate. Ignite at a red heat over a burner for about 10 minutes, and cool. Dissolve the melt in 2 mL of freshly distilled water, warming if necessary, and slowly add 2 mL of ammonium molybdate TS to the solution: a deep yellow color is produced.

B: [ Caution — Avoid contact with o-tolidine when performing this test, and conduct the test in a well- ventilated hood. ] Place 1 drop of the yellow silicomolybdate solution obtained in Identification test A on a filter paper, and evaporate the solvent. Add 1 drop of a saturated solution of o-tolidine in glacial acetic acid to reduce the silicomolybdate to molybdenum blue, and place the paper over ammonium hydroxide: a greenish blue spot is produced.

pH á 791 ñ : between 3.5 and 5.5, in a 1 in 25 dispersion.

Loss on drying á 731 ñ — Dry it in a tared platinum crucible at 105° for 2 hours: it loses not more than 2.5% of its weight. Retain the dried specimen, in the crucible, for the test for Loss on ignition.


Loss on ignition á 733 ñ — Ignite the portion of Colloidal Silicon Dioxide, retained from the test for Loss on drying, at 1000 ± 25° to constant weight: the previously dried Colloidal Silicon Dioxide loses not more than 2.0% of its weight.

Arsenic, Method I á 211 ñ— Prepare the Test Preparation as follows. Transfer 2.5 g to a flask, add 50 mL of 3 N hydrochloric acid, and reflux for 30 minutes using a water condenser. Cool, filter with the aid of suction, and transfer the filtrate to a 100-mL volumetric flask. Wash the filter and flask with several portions of hot water, and add the washings to the flask. Cool, dilute with water to volume, and mix: a 15.0-mL portion of this solution, to which 3 mL of hydrochloric acid has been added, meets the requirements of the test, the addition of the 7 N sulfuric acid being omitted. The limit is 8 µg per g.

Organic volatile impurities, Method IV á 467 ñ : meets the requirements.

Assay— Transfer about 500 mg of Colloidal Silicon Dioxide to a tared platinum crucible, ignite at 1000 ± 25° for 2 hours, cool in a desiccator, and weigh. Add 3 drops of sulfuric acid, and add enough alcohol to just moisten the sample completely. Add 15 mL of hydrofluoric acid, and in a well-ventilated hood evaporate on a hot plate to dryness, using medium heat (95° to 105°) and taking care that the sample does not spatter as dryness is approached. Heat the crucible to a red color with the aid of a Bunsen burner. Ignite the residue at 1000 ± 25° for 30 minutes, cool in a desiccator, and weigh. If a residue remains, repeat the procedure, beginning with “add 15 mL of hydrofluoric acid. ” The weight lost by the assay specimen, previously ignited at 1000 ± 25°, represents the weight of SiO 2 in the portion taken.


Auxiliary Information—
Staff Liaison : Catherine Sheehan, Senior Scientific Associate
Expert Committee : (EMC) Excipients: Monograph Content
USP27–NF22 Page 2928
Phone Number : 1-301-816-8262

[ Last edited by 小小强 on 2006-8-28 at 21:54 ]
回复此楼
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
相关版块跳转 我要订阅楼主 zhangxiaohang 的主题更新
普通表情 高级回复 (可上传附件)
最具人气热帖推荐 [查看全部] 作者 回/看 最后发表
[考研] 313求调剂 +3 卖个关子吧 2026-03-31 3/150 2026-03-31 08:25 by yyyyry
[考研] 求调剂 +3 图鉴212 2026-03-30 3/150 2026-03-31 00:31 by jp9609
[考研] 22408 359分调剂 +4 Qshers 2026-03-27 7/350 2026-03-30 21:30 by Qshers
[考研] 085600 295分求调剂 +7 W55j 2026-03-30 9/450 2026-03-30 20:36 by dick_runner
[考研] 286分调剂 +10 Faune 2026-03-30 11/550 2026-03-30 20:35 by 啊李999
[考研] 材料学硕333求调剂 +14 北道巷 2026-03-24 14/700 2026-03-30 18:59 by 源_2020
[考研] 化学0703 调剂 306分 一志愿211 +8 26要上岸 2026-03-28 8/400 2026-03-30 16:39 by herarysara
[考研] 071010 323 分求调剂 +3 Baekzhy 2026-03-27 3/150 2026-03-30 14:24 by andresqi
[考研] 291求调剂 +5 Y-cap 2026-03-29 6/300 2026-03-29 13:18 by mumin1990
[考研] 一志愿北京理工大学本科211材料工程294求调剂 +8 mikasa的围巾 2026-03-28 8/400 2026-03-29 12:48 by 无际的草原
[考研] 330分求调剂 +5 qzenlc 2026-03-29 5/250 2026-03-29 07:37 by 无际的草原
[考研] 283求调剂 +3 A child 2026-03-28 3/150 2026-03-28 15:41 by ms629
[考研] 材料求调剂一志愿哈工大324 +7 闫旭东 2026-03-28 9/450 2026-03-28 08:51 by Xu de nuo
[考研] 308求调剂 +7 墨墨漠 2026-03-27 7/350 2026-03-28 07:43 by 热情沙漠
[考研] 0703化学338求调剂! +6 Zuhui0306 2026-03-26 7/350 2026-03-27 10:35 by shangxh
[考研] 324求调剂 +5 hanamiko 2026-03-26 5/250 2026-03-27 10:33 by wangjy2002
[考研] 081200-11408-276学硕求调剂 +3 崔wj 2026-03-26 3/150 2026-03-26 19:57 by nihaoar
[考研] 化学调剂一志愿上海交通大学336分-本科上海211 +4 小鱼爱有机 2026-03-25 4/200 2026-03-26 10:19 by aa331100
[考研] 285求调剂 +3 AZMK 2026-03-24 3/150 2026-03-25 12:23 by userper
[考研] 一志愿吉林大学材料与化工303分求调剂 +4 为学666 2026-03-24 4/200 2026-03-25 11:27 by BruceLiu320
信息提示
请填处理意见