化学药中理化常数检测方案

极少量、微量粉末的颜色测量 The instrument illustrated below is an UltraScan PRO. Measurements on an UltraScan VIS or ColorQuest XE would be carried out in a very similar fashion. Batch-to-batch color consistency (whiteness， for some) is an important indicator of quality for manypowders. In the pharmaceutical industry， for instance， the whiteness of powder may be an indication of itsfreshness or purity. Frequently only a small amount of powder may be available for measurement. By convention， the instrument geometry most commonly used to measure the color of powder is adirectional (45°/0°or 0°/45°) geometry instrument such as the LabScan XE. However， it is also possibleto measure powder color using a diffuse geometry instrument such as the HunterLab UltraScan PROspectrophotometer with appropriate sample devices. The UltraScan PRO The Application Powders have several non-uniform characteristics that require compensating preparation andpresentation techniques in order to ensure a repeatable sample measurement. Powders come in the form of fine particulates-not a solid sample-and must be measuredthrough a clear glass window in order to be effectively made into a solid. Powders exhibit light trapping between the particles and will be sensitive to ambient light and tosmall differences in the optical configuration of the instrument. Using a sufficient sample thickness willminimize these effects. Powders may be slightly fluorescent， which means that they will be sensitive to the UV contentof the light source. If fluorescence is an issue， use of the UV control option is recommended. Powders in the pharmaceutical industry have the additional characteristic of being very expensive， andso normal powder sampling techniques are not economically suitable. Sampling techniques that use avery small sample size (approximately 0.4 cc)are more cost-effective in this situation. Note： If inter-instrument agreement is a concern when measuring powders， all the instruments used forthose measurements MUST be the same model to minimize measurement differences. RecommendedSingle-Number Index Recommended Color Scale YI D1925 (2/C)， YI E313， WI E313 for indication of yellowness and/or whiteness，Y Brightness Recommended D65/10°.C/2° may also be used. Illuminant/Observer Measurement Method 1. Configure your software to read using the desiredcolor scale， illuminant， and observer. 2. Install the SAV port (UltraScan VIS or ColorQuest XE) or the special standardization port plate from the optionalsemi-micro powder sample accessory (HunterLab PartNumber D02-1012-313 for the UltraScan VIS orColorQuest XE or D02-1012-931 for the UltraScanPRO)， and standardize the instrument in a reflectancemode for the 0.390 inch (9.906 mm) area view for theUltraScan PRO (or the 0.375 inch (9.575 mm) area viewfor the UltraScan VIS or ColorQuest XE). 3. Replace the standardization port plate with themodified port plate. 4. Place the powder to be measured into the powderholder. 5. Pack the powder down using the plunger. Do notovertighten the powder holder. The powder should be atleast 1/2-cm deep in the holder. 6. Place the powder holder into the port plate. 7. Take a single color reading of the powder. Dump，refill， and read the powder at least three times from the same batch. Average the three color readings for a single color measurement representing the color of the batch. Averaging multiple readings minimizes measurement variation associated with non-uniform samples. 8. Record the average color values for the sample batch.