| Abstract: | A procedure relying on high performance liquid chromatography, for the estimation of fermentable carbohydrates in wort, has been tested collaboratively and adopted by the Institute of Brewing Analysis Committee as a Recommended Method. A radially compressed cartridge containing silica modified with tetraethylenepentamine is used with an eluting solvent of acetonitrile/water. The results of a preliminary trial indicated that better precision is achieved using manual measurements of peak height and omitting an internal standard. In the main trial where 5 laboratories analysed 5 sample pairs the repeatability (r95) and reproducibility (R95) values found with their mean concentration levels (m) to which they are applicable were: fructose (0.0256 + 0.0660m) and (0.0711 + 0.0691m) for 0.17–1.01 g/100 ml; glucose 0.090m and 0.139m for 0.80–2.07 g/100 ml; sucrose 0.095 and (0.0746 + 0.1663m) for 0.12–3.88 g/100 ml; maltose 0.219 and 0.917 for 4.17–6.09 g/100 ml; maltotriose 0.122 and 0.236 for 0.97–1.19 g/100 ml. The precision values for the sums of the total fermentable sugars were 0.578 and 1.040 for 6.71–14.24 g/100 ml. |
