Page 23 - Analytical method for food addtives

11
12
multivariate calibration
nm. Partial least
Between 400 and
squares (PLS)
nm
used
800
485
The colourants were fixed in Sephadex
mm cells for spectrophotometric
DEAE A-25gel at pH 2.0 and packed
Extraction of the ion-pair into
determination
n-butanol
into 1
Ion-pair formation with octadecyl-
trimethylammonium bromide at
Samples dissolved in water and
Sample preparation Reference Detection Extraction 8 nm 520 Nova-Pak C18 column with gradient Diluted with water and filtered mL/min) with methanol- elution (1.5 7 containing phosphate buffer of pH mM tetra-butylammonium bromide 5 9 MULTv3.0 Quimio Computer program that determines Diluted with water and program concentrat
filtered
pH 5.6
Matrix Beverages, gelatine, syrups Commercially available dyes Soft drinks, fruit liqueurs and ice-cream Soft drinks Soft drinks, sweets and fruit jellies

Method Ion-pair HPLC Spectro- photometry visible Solid-phase spectrophotometry Spectro- photometric Solid-phase spectrophotometry
(b)