Page 243 - Analytical method for food addtives

Colorimetric method is more economical and rapid than
interfering substances and the colorimetric specificity.
methods using TLC
g oil in 100 mL petroleum 19 Method A: (Fe(III) – TPTZ). Ferric chloride and TPTZ were added successively to the sample. Diluted with ether. Extract with 4 × 20 mL acetonitrile. water and heated in a boiling water bath, cooled Combine and evaporate to dryness. phosphoric acid added. Made to volume. Absorbance Dissolve in aqueous methanol

Dissolve 10 10 extracted as for oil samples fat

Hydrogenated vegetable fat

Oils Lard Foods = 2,4,6-tripyridyl-S-triazine = triphenyl tetrazolium chloride = butylated hydroxyanisole = butylated hydroxytoluene = propyl gallate

Spectro- photometric Derivative spectrometry Voltammetric UV, TLC–UV, colorimetry, TLC–colorimetry TPTZ TTC BHA BHT PG