Direct Analysis of Dark Honeys for Total Content of Copper and Its Fractionation Forms

Abstract

Suitability of direct analysis of honey solutions by air-acetylene flame atomic absorption spectrometry for reliable measuring total concentrations of Cu was evaluated and compared with determinations completed after open vessel wet oxidative digestion of honeys with a mixture of HNO 3 and H 2 O 2 . Total Cu concentrations determined in amber to dark color raw honeys were within 0.95-1.68 mg kg −1 . Additionally, solutions of honeys were subjected to fractionation analysis by means of a two-column solid phase extraction procedure with a non-ionic adsorbing resin Amberlite XAD-16 and a strongly acidic cation exchanger Dowex 50W × 8-200. Another set of solutions was subjected to fractionation analysis using ultrafiltration with membranes of molecular weight cut-off size of 100, 50, 30, 10, and 5 kDa. Both approaches used to partition Cu species enabled to obtain information on chemical and physical fractionation patterns. It seems that predominant classes of species (67-94%) are cationic and residual species which could be the most accessible forms of Cu from honey due to very low molecular size and possible association with certain organic compounds.

Assessment of heavy metals in propolis and soil from the Pelagonia region, Republic of Macedonia

“…may enhance the corrosion of beekeeping tools made of galvanized steel, aluminum, and brass, as well as containers used for storage and shipment. Storing bee products in galvanized containers can be source of Zn contamination, iron/steel based parts can be a source of Cr, and brass components can be a source of Zn and Cu [14,15].…”

“…There are very few published studies that take into consideration both the contents of the heavy metals in soil and the contents of the same heavy metals in propolis (and other bee products). Additionally, extra caution should be taken in terms of the techniques and type and quality of equipment used to gather and store the propolis in order to avoid its contamination with heavy metals, which has been addressed by several authors [13][14][15][16].…”

Determination of traces of copper and zinc in honeys by the solid phase extraction pre-concentration followed by the flame atomic absorption spectrometry detection

“…In the case of direct analysis of water solutions of honey samples, the honey matrix, containing primarily fructose and glucose, is reported to deteriorate signals of determined elements and their detection limits (DLs), particularly when the content of honey samples in respective solutions is higher than 2 % m/v (Lopez Garcia et al 1999 ; dos Santos et al 2008 ; Pohl and Sergiel 2010 , 2012 ; Sergiel and Pohl 2010 ). Therefore, small samples of honey are handled at once using this method, but traces of certain elements cannot be determined.…”