These instructions are to be the same as those appearing on the corresponding USP Reference Standard label. The list that follows presents the instructions for the proper use and storage of each required USP Reference Standard. The USP Reference standards section of an individual USP or NF monograph or general chapter names each USP Reference Standard required for assay and test procedures and refers to this chapter for additional information and instructions. When using typical amounts, about 50 mg, of the Reference Standard, titrate with a fourfold dilution of the Reagent. Instrumental or microanalytical methods are acceptable for this purpose. Where the titrimetric determination of water is required at the time a Reference Standard is to be used, proceed as directed for Method I under Water Determination 921. Do not use the original container as the drying vessel, and do not dry a specimen repeatedly at temperatures above 25. Where a USP Reference Standard is required to be dried before using, transfer an amount, sufficient after drying, to a clean and dry vessel. Where special drying requirements for Reference Standards are found in specific sections of USP or NF monographs, those supersede the usual instructions (see Procedures under Tests and Assays in the General Notices and Requirements).
Assay and test results are determined on the basis of comparisons of the specimen under test with a USP Reference Standard that has been freed from or corrected for volatile residues or water content as instructed on the label.
0 kommentar(er)
