Many Pharmacopeial articles either are hydrates or contain water in adsorbed form. As a result, the determination of the water content is important in demonstrating compliance with the Pharmacopeial standards. Generally one of the methods given below is called for in the individual monograph, depending upon the nature of the article. In rare cases, a choice is allowed between two methods. When the article contains water of hydration, Method I (Titrimetric), Method II (Azeotropic), or Method III (Gravimetric) is employed, as directed in the individual monograph, and the requirement is given under the heading Water. Unless otherwise specified in the monograph, determine the water by Method Ia .