Page 26 - Analytical method for food addtives

8 Analytical methods for food additives

Reference 13 14 nm 15 16 17

nm. First derivative spectrum intervals. First and,

Detection 350–700 was obtained 300–700 nm in 5 second derivatives were analysed by (PLS) multivariate calibration nm 216 kV nm 254 mM

The colourants were isolated from the food matrices by SPE using polyamide mm cells for spectrophotometric determination No separation step is required. Method was used to determine synthetic mixtures of these dyes in different ratios from 1:1:1 to 1:5:5 or even higher A background solution consisting of mM borat

Method conditions sorbent packed into 1 separation voltage separation voltage 28 KH 2 PO 4 /Na 2 B 4 O 7 /3 as background electrolyte

mL mL 15
g in 100

Sample preparation Samples diluted 5–20 water Food samples were diluted to mL with the addition of 5 25 acetate buffer at pH 4.5 and water This method is applied to samples containing 3 dyes to determine each dye under optimum conditions Samples used as is or diluted with water Sample, either concentrated or directly a

Confectionery carbonated drinks Commercial Non-alcoholic beverages and fruit-flavoured Beverages – strawberry and orange drinks

Matrix products Candy and syrups

Table 1.1 cont’d (c) Method First-derivative spectrophotometry Simultaneous spectrophotometry Derivative spectrophotometricproducts ratio spectrum-zero crossing Capillary zone electrophoresis (CZE) CZE