Page 138 - Analytical method for food addtives

E220–8: Sulphites 87

Reference 2–5 6,7 8,9 12,13

Method conditions Reflux with HCl in distillation apparatus. Sweep SO 2 through a condenser with nitrogen into hydrogen peroxide solution. SO 2 oxidised to sulphuric acid which is titrated with standardised NaOH solution Sulphite oxidised to sulphate in the presence of sulphite oxidase with the liberation of hydrogen peroxi

g samples add 100 mL 5 % ethanol:water mixture Liquid samples: adjusted to pH 7.5–8.0 with NaOH (2 mol/L). Solid samples: homogenise thoroughly and extract with water 5 min at 60 ºC g antifoam + 5 % g sample + 0.5 g. Homogenise if Solid foods: Add 3–30 times TCM solution to test portion, blend until homogeneous and c

Sample preparation
Summary of methods for sulphites in foods Matrix To 50 Foods . Foods 10 Foods alcohol to 100 necessary Foods and beverages solution to 1–2

Table 8.1 (a) Method Optimised Monier–Williams Enzymatic Differential pulse polarographic FIA