Table 1
Operating conditions applied in the fractionation analysis of magnesium in olives
Experiment Fraction Reagent/material Experimental conditions
Digestion Total Mg Concentrated HNO3 (25 + 25) min at 150 ◦C
Extraction with CCl4 Lipid-bound Mg CCl4 2 h at 25 ◦C
Extraction with CHCl3 Chlorophyll-bound Mg CHCl3 2 h at 25 ◦C
Extraction with water Water-soluble Mg Distilled water 24 h at 25 ◦C
Filtration Particulate 0.45 m filter Vacuum filtration
Ion exchange Cationic Dowex 50Wx8-40 In column
Sorption Polyphenol-bound Amberlite XAD-4 In microcolumn
Precipitation Polysaccharide-bound Ethanol Centrifuge
Extraction with pepsin + HCl Absorbable Mg in stomach Pepsin in 0.1M HCl 2 h at 37 ◦C
Extraction with n-octanol Absorbable Mg in intestine n-Octanol 2 h at 37 ◦C