title: Simplified sample treatment for the determination of total concentrations and chemical fractionation forms of Ca, Fe, Mg and Mn in soluble coffees.
abstract: A simpler, and faster than wet digestion, sample treatment was proposed prior to determination of total concentrations for selected macro- (Ca, Mg) and microelements (Fe, Mn) in soluble coffees by flame atomic absorption spectrometry. Samples were dissolved in water and acidified with HNO3. Precision was in the range 1-4% and accuracy was better than 2.5%. The method was used in analysis of 18 soluble coffees available on the Polish market. Chemical fractionation patterns for Ca, Fe, Mg and Mn in soluble coffees, as consumed, using a two-column solid-phase extraction method, determined Ca, Mg and Mn were present predominantly as cations (80-93% of total content). This suggests these elements are likely to be highly bioaccessible.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, Wroclaw University of Technology, Smoluchowskiego 23, 50-372 Wroclaw, Poland. Electronic address: pawel.pohl@pwr.wroc.pl.
authors.forename: Pawel
authors.initials: P
authors.lastname: Pohl
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, Wroclaw University of Technology, Smoluchowskiego 23, 50-372 Wroclaw, Poland.
authors.forename: Ewelina
authors.initials: E
authors.lastname: Stelmach
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, Wroclaw University of Technology, Smoluchowskiego 23, 50-372 Wroclaw, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Szymczycha-Madeja
mesh_terms: D002118:Calcium / Q000032:analysis*; D003069:Coffee / Q000737:chemistry*; D007501:Iron / Q000032:analysis*; D008274:Magnesium / Q000032:analysis*; D008345:Manganese / Q000032:analysis*; D052616:Solid Phase Extraction; D013054:Spectrophotometry, Atomic / Q000379:methods
chemical_list: D003069:Coffee; D008345:Manganese; D007501:Iron; D008274:Magnesium; D002118:Calcium
keywords: Calcium; Direct analysis; Flame atomic absorption spectrometry; Iron; Magnesium; Manganese; Solid phase extraction; Soluble coffee