Iwona Sergiel

Characterisation of honeys according to their content of phenolic compounds using high performance liquid chromatography/tandem mass spectrometry

A simple, fast and specific high performance liquid chromatography separation with an electro-spray ionisation tandem mass spectrometry detection in a negative single reaction ion monitoring scan mode was developed and used for the characterization of Polish honeys according to the content of phenolic acids, including caffeic, chlorogenic, p-coumaric, ferulic, homogentisic, p-hydroxybenzoic and vanillic acids, and flavonoids, i.e., apigenin, genistein, hesperetin, kaempferol, luteolin, rhamnetin, rutin, tricetin and quercetin. Target compounds were isolated and pre-concentrated from the honey matrix by means of the solid phase extraction using Strata X (500mg) cartridges. Analysed honeys did not contain tricetin and genistein. Hesperetin was determined for the first time in heather and linden honeys while rutin in rape honey.

Suitability of three-dimensional synchronous fluorescence spectroscopy for fingerprint analysis of honey samples with reference to their phenolic profiles.

The suitability of a right-angle geometry three-dimensional synchronous fluorescence spectroscopy (3D-SFS) for the differentiation and classification of different honey types, including acacia, buckwheat, heather, linden, multiflower and rape honeys, was evaluated with reference to their phenolic profiles. The fraction of phenolic compounds was initially isolated and pre-concentrated from analyzed samples by means of polymeric reversed phase Strata X solid phase extraction (SPE) cartridges. A thoughtful analysis of 3D-SF spectra of resulting methanolic extracts of honey samples containing the separated fraction of phenolics and standards of phenolic acids and flavonoids revealed that the proposed methodology based on SPE and 3D-SFS is capable of discriminating honey samples due to different floral sources in a fast and straightforward way.

Determination and Fractionation of Metals in Honey

The composition of metals in honey is correlated with the type of plant species from which resources (nectar, pollen, propolis, honeydew) are collected and ripened by honey bees into honey. However, the botanical origin is strictly attributed to the geographical locality of an apiary, because the soil composition and the climatic conditions determine the presence of certain melliferous flowers and trees harvested by bees. The environmental pollution or other anthropogenic processes and effects should also be considered as an additional source of metals in honey, namely Cd, Cr, Cu, Fe, Ni, Pb and Zn. These metals may condemn the quality and food safety of honey, and exhibit a potential hazard to human health. The present literature survey reviews original works of the last decade which relate to the atomic and mass spectrometric analysis of honey on the presence of major, minor and trace metals. Different aspects of such analysis are treated in detail, including the methods of choice, calibration strategies, sample treatments, and preparation procedures applied. The suitability of the metals content for the classification of honey according to the botanical and geographical origins or indication and control of the environmental pollution are discussed.

Evaluation of the total content and the operationally defined species of copper in beers and wines.

A two-column solid phase extraction was used to determine the operationally defined speciation of Cu in lager beers and red wines. Applying a nonionic macroreticular adsorbing resin Amberlite XAD-16 and a gel type strong cation exchange resin Dowex 50Wx8-200, three different groupings of the chemical forms of Cu, including the hydrophobic, the cationic, and the residual species fractions, were separated and determined. The total content of Cu in the analyzed samples and its concentrations in the distinguished fractions were measured using flame atomic absorption spectrometry without any special preparation of the sample solutions. It was found that the residual species (72-82% of the total content), being polar and noncationic forms of Cu, are the most abundant fraction of Cu in the analyzed beers. In the case of wines, the fraction of the hydrophobic species was established to have the highest share in the total Cu content, that is, 27-77%. This fraction was presumed to contain relatively strong complexes of Cu with various flavonoids and other polyphenols.

Different Aspects of the Elemental Analysis of Honey by Flame Atomic Absorption and Emission Spectrometry: A Review

The elemental composition of honey is correlated with the botanical provenience of nectar, pollen, and honeydew that are collected and ripened by bees. In addition to this, the geographical origin related to the locality of an apiary, the soil composition, and climatic conditions may contribute to the origin of elements in honey. The environmental pollution or other anthropogenic processes and activities also have an effect on the quality and the safety of honey since they may be accompanying sources that lead to its contamination and the presence of various trace elements (Cd, Cr, Cu, Fe, Ni, Pb, and Zn). This review article covers the literature devoted to the analysis of honey carried out by the most popular and commonly utilized flame atomic absorption and emission spectrometry, which was published from 1999 to 2011. Various aspects of such analysis are treated in detail, including ways of the sample preparation, the calibration, and the quality assurance of results. In addition, methods and results related to the fractionation analysis of elements in honey by means of chromatographic and non-chromatographic approaches are described.

Direct Determination of the Total Concentrations of Magnesium, Calcium, Manganese, and Iron in Addition to their Chemical and Physical Fractions in Dark Honeys

The present work demonstrates a very simple and rapid method for the reliable determination of total concentrations of Mg, Ca, Mn, and Fe in dark honeys by means of flame atomic absorption spectrometry without any special sample pretreatment except for dissolution in water. An analytical scheme for the partitioning of Mg, Ca, Mn, and Fe in analyzed honeys was proposed as well. For a complementary evaluation of fractionation patterns for studied metals, a two linked column solid phase extraction procedure with a nonionic adsorbing resin Amberlite XAD-16 and a strong cation exchange resin Dowex 50 W × 8–200 in addition to an ultrafiltration procedure with five membranes having molecular weight cut-offs of 5, 10, 30, 50, and 100 kDa were used. In the course of the fractionation analysis, it was found that the most dominant group of species is the one containing cationic forms of metals bound to low molecular weight (<5 kDa, 5–10 kDa) natural honey bioligands and is mostly the case of simple ions and labile species of Mg, Ca, Mn, and Fe. Correspondingly, the contribution of the cationic fraction for these metals in analyzed dark honeys was up to 96% (Mg), 95% (Ca), 90% (Mn), and 86% (Fe). A significant contribution of the hydrophobic fraction was also established; it was maximally 10, 18, 20, and 25% for Mg, Ca, Mn, and Fe, respectively.

Determination of the Total Content of Calcium and Magnesium and Their Bioavailability in Ripened Bee Honeys

An analytical scheme for the fractionation and the determination of Ca and Mg in different bee honeys is presented. Using tandem column solid phase extraction based on a nonionic macroreticular adsorbing resin Amberlite XAD-16 and a gel-type strong cation exchange resin Dowex 50Wx8-200, three different groups of the Ca and Mg species were separated, including the hydrophobic, the cationic, and the residual species fractions. The concentrations of Ca and Mg were measured by means of flame atomic absorption spectrometry without any special chemical preparation of the analyzed samples. When regarding the total concentrations of Ca and Mg in the analyzed ripened floral and honeydew honeys, it was assessed that the most abundant group of the metal species was the cationic fraction, contributing for some honeys up to 96.3 and 97.0% of Ca and Mg, respectively. A relatively significant contribution of the hydrophobic fraction was also found, i.e., up to 20.1% for Ca and 23.0% for Mg.