A new method for quantifying iodine in a starch-iodine matrix.
A rapid and sensitive method for quantifying iodine in intact starch granules using gas chromatography is described with detection limits as low as 0.2% (w/w) iodine in starch. Sample preparation includes NaBH(4) reduction of the various iodine species associated with starch to the colorless soluble iodide ion, followed by its quantitative derivatization to EtI using Et(3)O(+)BF4- in CH(2)Cl(2). Identification and quantification of EtI is carried out by extraction and injection of the EtI so generated in CH(2)Cl(2) into a gas chromatography-mass spectrometer (GC-MS). Routine quantification of EtI was then performed using GC with a flame ionization detector (GC-FID). Results for different iodine:potassium iodide ratios of the initially bound iodine and for seven different starch matrices showed that in all cases regression coefficients for the standards were high (R(2)>0.96).
Department of Food Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
Bruce A
BA
Manion
Bruce E
BE
Holbein
Massimo F
MF
Marcone
Koushik
K
Seetharaman
D002849:Chromatography, Gas; D005410:Flame Ionization; D008401:Gas Chromatography-Mass Spectrometry; D007455:Iodine / Q000737:chemistry*; D013213:Starch / Q000737:chemistry*
D013213:Starch; D007455:Iodine