Page 44 - Analytical method for food addtives

Analytical methods for food additives
20
Reference
5
8
Detection
nm
nm
216
427
using a Beckman DU-70 instrument
buffer at pH 10.5, hydrodynamic
kV separation
Analysed by spectrophotometry
mM borate
A background solution
Method conditions
injection and a 20
consisting of 15
voltage
% 9 Absorbance The mixture was shaken for 15 min M measured at then the gel beads were filtered off, nm and 525 mm cell and packed into a 1 nm 800 absorbance measured 10 TLC or Colour separated on reverse phase spectrophotometric C18 Sep-Pak cartridge and eluted with aqueous isopropanol soluti
mL with
mL acetate
Sample preparation Samples used as is or diluted with water Samples diluted in 5 buffer and diluted to 25 water Sample solution mixed with 1 HCl, ethanol sufficient for a 10 conc., water and Sephadex DEAE A-25 gel Liquid samples as is. Solid samples dissolved in water and filtered through sintered glass filter Ion-pa
Non-alcoholic beverages and fruit flavoured Beverages, gelatine, syrups Colourings confectionery Various foods Soft drinks
Matrix syrups caramel,
Table 2.1 cont’d (b) Method Capillary zone electrophoresis (CZE) Spectro- photometric Solid-phase spectro- photometry Rapid clean-up method for spectro- photometric and TLC methods Spectro- photometric