Water-soluble Cu, Fe, Mn and Zn species in nuts and seeds.

摘要

An approach was developed to estimate molecular weight distribution of water-soluble Cu, Fe, Mn and Zn species in Brazil nut, cupuassu seed and coconut pulp by size exclusion chromatography (SEC) coupled on-line to ultra-violet (UV) and off-line to graphite furnace atomic absorption spectrometry (GF-AAS) detectors and matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF-MS). SEC-UV analytical signals showed the prevalence of high molecular weight (HMW) species (79-1.7kDa for Brazil nut, 50-1.7kDa for coconut pulp, and 34-1.7kDa for cupuassu seeds). The Brazil nut SEC-UV, GF-AAS and MALDI-TOF mass spectra gave confirmation of the association of the elements with water-soluble compounds. The elemental profiles were associated with fractions of compounds of molecular weight 1.2-16kDa for Brazil nut, 1.7-13kDa for coconut pulp, and 1.2-7.6kDa for cupuassu seeds