An indirect back-titration method for the determination of (Ca + Mg) in flameproofed cotton fabrics is developed. Fabrics are boiled for 10-15 min with an excess of sodium-EDTA solution to extract and to bind the ('a and Mg, present in fabrics, into their corresponding EDTA complexes. The sodium-EDTA excess is titrated potentiometrically at pH 9.8 with CaCl2 solution, using a divalent-cation specific electrode or visually with Eriochrome Black T indicator. (Ca + Mg) in the range of 0.2 3% as Ca in fabrics are determined with an average error of 3 4% and a standard deviation of 0.2 0.3%
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