Page 258 - Analytical method for food addtives

170 Analytical methods for food additives

Reference 2 4 5 6

5 mL added to 10 mL Solution I (100 mM silver nitrate
mM mM cm long by 50 µm mM
mM NaOH and 656 The separation was performed on a capillary electro- psi). The neutral kV potential. The electrolyte used Capillary: fused silica 50 µm i.d. × 112.5 cm. Buffer; mM n-hexadecyltrimethylammonium hydroxide (pH 5.7). Wavelength: signal 350 nm, reference 275 nm. Applied kV. Injection: pressure of 50 k

Method conditions in aq acetic acid 30 %) and 10 mL Solution II (85 ammonium metavanadate, 150 sodium acetate). Stirred for 15 mins at room temperature and filtered. Colour absorbance measured at 530 nm phoresis P/ACE with UV detection at 200±10 nm. Injection was by pressure for 5 s (20 capillary was polyacrilamide coated

Sample preparation Thawed sample acidified to pH 1 N HNO 3 with 14 Dilution 1:1 with water and centrifugation or filtration Extracted with water, filtered, diluted M NaOH and deproteinised with 0.02 by an ultrafiltration filter (30 cut-off) Dilution 1:40 with water and filtered through 0.45 µm filter

Frozen musts and Orange juice Formula feeds

Matrix wine Wines

Table 13.1 cont’d (b) Method Rebelein’s colorimetric Capillary electrophoresis (CE) Capillary electrophoresis (CE) Capillary electrophoresis (CE)