Determination of cotton-bound glyoxal via an internal cannizzaro reaction by means of high-performance liquid chromatography.

Abstract

Glyoxal, a non-formaldehyde cross-linking agent, was applied in combination with aluminum sulfate hexadecahydrate to impart durable-press properties to cellulosic materials. The cotton fabric was impregnated with a pad bath formulation containing 6% (w/w) glyoxal and 4.5% (w/w) aluminum sulfate hexadecahydrate. The curing process was conducted at 140 degrees C for 3 min, thus affecting a cross-linkage between the cellulose chains. For the first time, a chromatographic method is presented that enables both qualitative and quantitative analysis of the portion of glyoxal that has reacted with the cellulosic material. For this purpose, the glyoxal-treated fabric was treated with an NaOH solution (c = 4 mol L(-1)) at 100 degrees C for 20 min. As a result, glyoxal was extracted from the cellulosic sample and converted into glycolate via an internal Cannizzaro reaction. Subsequently, the glycolate was analyzed chromatographically using the strong cation-exchange column Aminex HPX-87H as the stationary phase and sulfuric acid as the mobile phase. The detection limit was 1.87 mg L(-1) (UV detection). The recovery was 85%. Dry crease wrinkle recovery measurements gave evidence that the cross-linkage was removed completely. The application of the analytical technique developed in the present study demonstrated that the amount of glyoxal that had reacted with the cellulose was 15.7 +/- 0.72 mg/g of fabric. In addition, glycolate thus formed was well separated from non-formaldehyde durable-press finishing agents based on polycarboxylic acids such as 1,2,3,4-butanetetracarboxylic acid or citric acid.