標準號：ISO 5993-1979
中文標準名稱：工業用氫氧化鈉 汞含量的測定 無焰原子吸收光譜測定法
英文標準名稱：Sodium hydroxide for industrial use; Determination of mercury content; Flameless atomic absorption spectrometric method
標準類型：G10
發布日期：1999/12/31 12:00:00
實施日期：1999/12/31 12:00:00
中國標準分類號：G10
國際標準分類號：71.060.40
適用范圍：Covers a method applicable to liquid or solid products having mercury contents greater than 0,02 mg/kg. The principle of determination is based on oxidation of the mercury contained in a test portion to mercury(II) ions by potassium permanganate in the presence of sulphuric acid, reduction of the excess oxidant by hydroxylammonium chloride, reduction of the mercury(II) ions to mercury by tin(II) chloride, entrainment of the mercury in air or nitrogen, passage of the gaseous mixture through a measuring cell, and measurement of the absorption at a wavelength of 253,7 nm.