USP29-231重金属EN+CN..doc

231 HEAVY METALS 重金属 This test is provided to demonstrate that the content of metallic impurities that are colored by sulfide ion, under the specified test conditions, does not exceed the Heavy metals limit specified in the individual monograph in percentage (by weight) of lead in the test substance, as determined by concomitant visual comparison (see Visual Comparison in the section Procedure under Spectrophotometry and Light-Scattering 851) with a control prepared from a Standard Lead Solution. [NOTE—Substances that typically will respond to this test are lead, mercury, bismuth, arsenic, antimony, tin, cadmium, silver, copper, and molybdenum.] 提供本检验来证明与硫化物离子作用显色的金属杂质含量，在规定检验条件下，不得超过各论中规定的重金属限度供试品中铅的百分比（重量比），如同通过与标准铅溶液配制的对照进行视觉比较决定的（参看分光光度法和光散射法851中规程部分的视觉比较）。[注意：与本检验起反应的代表性物质为铅、汞、铋、砷、锑、锡、镉、银、铜和钼。] Determine the amount of heavy metals by Method I, unless otherwise specified in the individual monograph. Method I is used for substances that yield clear, colorless preparations under the specified test conditions. Method II is used for substances that do not yield clear, colorless preparations under the test conditions specified for Method I, or for substances that, by virtue of their complex nature, interfere with the precipitation of metals by sulfide ion, or for fixed and volatile oils. Method III, a wet-digestion method, is used only in those cases where neither Method I nor Method II can be used. 除各论另有规定外，用方法I测定重金属含量。方法I用于规定条件下的澄清、无色供试品，方法II用于方法I规定条件下的非澄清、无色供试品，或者，方法III湿法消解 Special Reagents Lead Nitrate Stock Solution— Dissolve 159.8 mg of lead nitrate in 100 mL of water to which has been added 1 mL of nitric acid, then dilute with water to 1000 mL. Prepare and store this solution in glass containers free from soluble lead salts. Standard Lead Solution— On the day of use, dilute 10.0 mL of Lead Nitrate Stock Solution with water to 100.0 mL. Each mL of Standard Lead Solution contains the equivalent of 10 μg of lead. A comparison solution prepared on the basi