Sulphodichlorohydroxydimethyl Fuchson Dicarboxylic Acid as a Colorimetric Reagent for the Microdetermination of Beryllium

Beryllium forms a pink-coloured chelate (ʎmax 540mμ) with Chrome Azurol S (sulphodichlorohydroxy­dimethyl fuchson dicarboxylic acid, colour index 723). This has been used in the calorimetric determination of beryllium on a micro scale and conditions for the measurements have been worked out. Beer's law is adhered to with 0.01 to 0.33 p.p.m. of beryllium in presence of a large excess of Chrome Azurol S. Measurements may be made over a wide range of temperature between pH 4.0 and 6-8. The sensitivity is-0.00045 γ/cm2 (Sandell) and 0.0045 γ/cm2 (practical). Copper, aluminium, iron, thorium, zirconium, borate, carbonate, oxalate, and citrate interfere in the determination