药物中水分含量的多少直接影响药物的质量。为此药典对许多生药、合成药或制剂规定了含水量限度。生药含水量测定,我国药典采用重量法(或称干燥失重)和甲苯法(又称共沸法)。国外药典有关项下与我国药典方法基本一致,仅在某些操作细节上略有差异。实际工作中,这两种方法存在着取样量大、费时及操作繁杂等缺点。 The amount of water in the drug directly affects the quality of the drug. For this reason pharmacopoeias prescribe water limits for many crude drugs, synthetic drugs or preparations. The moisture content of crude drug is determined. The Chinese Pharmacopoeia uses gravimetric method (or dry weight loss) and toluene method (also known as azeotropic method). The relevant items of the foreign Pharmacopoeia are basically the same as the methods of the Chinese Pharmacopoeia, and there are only slight differences in certain operating details. In practical work, these two methods have the disadvantages of large sampling volume, time-consuming and complicated operations.