所述方法的原理是还原提取液中的铁，络合，将络合物提取到氯仿中，并通过分子吸收光谱仪在533nm处测量所得彩色络合物的光密度，或用氢氟酸和高氯酸蒸发，将残余物溶解在盐酸中，使用火焰原子吸收光谱仪在248.3 nm处测量吸收。测量铁的浓度，以其氧化物Fe2O3表示。适用于从任何种类的玻璃或玻璃器皿中获得的提取液的分析。

The principle of the method specified is reducing the iron in the extract solution, complexing, extracting the complex into chloroform and measurement of the optical density of the resulting colour complex by means of a molecular absorption spectrometer at 533 nm or evaporating with hydrofluoric and perchloric acids, dissolving of the residue in hydrochloric acid, measuring the absorption using a flame atomic absorption spectrometer at 248,3 nm. Measures the concentration of iron, expressed as its oxide Fe₂O₃. Applies to the analysis of extract solutions obtained from any kind of glass or glassware.