This standard applies to the determination of bismuth content in antimony and antimony trioxide, with a determination range of 0.0010% to 0.10%. The method involves dissolving antimony samples with aqua regia, dissolving antimony trioxidation samples with muriatic acid-hydrobromic acid, and separating antimony under specific conditions. After separating antimony, the Absorbance of bismuth is measured at a wavelength of 223.1 nm using AtomicAbsorption Spectroscopy. The standard describes the reagent preparation, equipment and operation procedures in detail to ensure the accuracy and reliability of measurement.