Determination of Total Concentrations and Chemical and Physical Fractionation Forms of Manganese in Infusions of Ground Coffees

Abstract

A simple and fast method of the determination of total Mn in infusions of ground coffees was proposed and included the acidification of infusions with HNO3 followed by the analysis by flame atomic absorption spectrometry. The method provided the precision and the accuracy better than 3 %. In addition, chemical and physical fractionation patterns of Mn in coffee infusions were assessed using solid phase extraction and ultrafiltration-based procedures, respectively. It was found that Mn in infusions of ground coffees is predominantly present in the form of cationic (64-81 % of the total content) low molecular weight (61-68 % of the total content) species. This points out that this metal is highly bioaccessible from the coffee brew. © 2013 The Author(s).