资源描述
单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,附录选读,Determination of Loss on Drying,Paper Chromatography,Appendix IX D,.,Determination of Loss on Drying,（,测定法）(干燥失重),(,Ph.,Eur,.method 2.2.32),Loss on drying is the loss of weight,expressed as%w/w.,Method,Place the prescribed quantity of the substance being examined in a weighing bottle previously dried under the conditions,prescribed,for the substance being examined.,prescribed quantity,规定的量,being examined,待检的,weighing bottle,称量瓶,Place the prescribed quantity of the substance,being examined,in a weighing bottle,previously dried,under the conditions prescribed for the substance,being examined,.,照各药品项下规定的条件,Dry the substance to constant weight or for the prescribed time by one of the following procedures.,constant weight,恒重,prescribed time,规定的时间,(,a),In a,desiccator,The drying is carried out over,phosphorus,pentoxide,at atmospheric pressure and at room temperature.,Desiccator,干燥器,phosphorus,pentoxide,五,氧化二磷,atmospheric pressure,大气压,(,b),In,vacuo,The drying is carried out over,phosphorus,pentoxide,at a pressure of 1.5 to 2.5,kPa,at room temperature.,(,c),In,vacuo,within a specified temperature range,The drying is carried out over,phosphorus,pentoxide,at a pressure of 1.5,to 2.5,kPa,within the temperature,range specified in the monograph.,(,d),In an oven within a specified temperature range,.The drying is carried out in an oven within the temperature range specified in the monograph,specified,指定的,oven,烘箱,(,e),Under high vacuum.,The drying is carried out over,phosphorus,pentoxide,at a pressure not exceeding 0.1,kPa,at the temperature prescribed in the monograph.,high vacuum,高度真空,If other conditions are prescribed,the procedure to be used is described in full in the individual monograph,.,Appendix III E.,Paper Chromatography,色析法,示意图,：,圆形滤纸,纸层析,展开,Paper partition chromatography(PPC),下行法,上,行,法,(,Ph.,Eur,.method 2.2.26),Apparatus,The apparatus consists of a glass tank of suitable dimensions to accommodate the chromatographic paper used,ground at the top to take a closely-fitting glass lid and adapted as necessary for ascending or descending chromatography,.,ground,磨口,The chromatographic paper consists of suitable absorbent paper,cut into strips of convenient length and not less than 25 mm wide;,the paper is cut so that the mobile phase runs in the direction of the grain of the paper.,grain,纹理、谷物,颗粒,grain of the paper,纸纹,grain direction,纹理方向,色谱滤纸按纤维长丝方向切割,A fine pencil line is drawn horizontally across the paper,either 30 mm from one,end for ascending paper chromatography,or,for descending paper chromatography,fine,细微的,at such a distance from one end that when this end is,secured,in the solvent trough with the remainder of the paper hanging freely over the,guide rod,the line is parallel to and a few,centimetres,below the rod,secured,固定,trough,谷,沟,槽,guide rod,玻璃悬钩,The volume of the solution specified in the monograph is applied to a point on the pencil line.If the total volume to be applied would produce a spot more than 10 mm in diameter,the solution is applied in portions,each being allowed to dry before the next application.,When more than one chromatogram,is to be run on the same strip of paper,the solutions are spaced along the pencil line at points not less than 30 mm apart.,The top of the tank contains a device from which the chromatographic paper is suspended and which is capable of being lowered without opening the chamber.In the bottom of the tank is a dish to contain the mobile phase,into which the paper may be lowered.,Ascending paper chromatography,Use sufficient of the prescribed mobile phase to form a 25-mm layer in the dish,and,if prescribed,pour the saturating solvent between the dish and the walls of the tank.,Close the tank and allow to stand for 24 hours at 20 to 25 and maintain the tank at this temperature throughout the subsequent procedure.Insert the prepared paper into the tank,close the lid and allow to stand for 90 minutes,.,Lower the paper into the mobile phase and allow development to proceed for the distance or the time prescribed in the monograph.,development,展开,The paper should be protected from bright light during the development.Remove the paper from the tank and allow it to dry in air.The method of,visualisation,is described in the monograph.,bright light,强光,visualisation,目测法,
展开阅读全文