Metals In Honey Research Articles

A Biomimetic Sensor for the Classification of Honeys of Different Floral Origin and the Detection of Adulteration

The major compounds in honey are carbohydrates such as monosaccharides and disaccharides. The same compounds are found in cane-sugar concentrates. Unfortunately when sugar concentrate is added to honey, laboratory assessments are found to be ineffective in detecting this adulteration. Unlike tracing heavy metals in honey, sugar adulterated honey is much trickier and harder to detect, and traditionally it has been very challenging to come up with a suitable method to prove the presence of adulterants in honey products. This paper proposes a combination of array sensing and multi-modality sensor fusion that can effectively discriminate the samples not only based on the compounds present in the sample but also mimic the way humans perceive flavours and aromas. Conversely, analytical instruments are based on chemical separations which may alter the properties of the volatiles or flavours of a particular honey. The present work is focused on classifying 18 samples of different honeys, sugar syrups and adulterated samples using data fusion of electronic nose (e-nose) and electronic tongue (e-tongue) measurements. Each group of samples was evaluated separately by the e-nose and e-tongue. Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) were able to separately discriminate monofloral honey from sugar syrup, and polyfloral honey from sugar and adulterated samples using the e-nose and e-tongue. The e-nose was observed to give better separation compared to e-tongue assessment, particularly when LDA was applied. However, when all samples were combined in one classification analysis, neither PCA nor LDA were able to discriminate between honeys of different floral origins, sugar syrup and adulterated samples. By applying a sensor fusion technique, the classification for the 18 different samples was improved. Significant improvement was observed using PCA, while LDA not only improved the discrimination but also gave better classification. An improvement in performance was also observed using a Probabilistic Neural Network classifier when the e-nose and e-tongue data were fused.

Content of bioelements and toxic metals in honey of various botanical orgin from Lower Silesia

Analyzing the content of bioelements and toxic metals in honeys of various botanical origin is important for the consumers’ health. In addition, many authors notice that results of such analyses can help to identify the botanical and geographical origin of honey and to use the product as a bioindicator of the overall contamination of the environment. The content of As, Cd, Pb, Zn, Cu, Mn, Ni, Mg, Fe, Cr was determined in samples of nectar honey (acacia, linden, goldenrod, multifloral, buckwheat, oilseed rape) originating from some areas in the Province of Lower Silesia unexposed to industrial and traffic emissions. In order to demonstrate differences in concentrations of the metals in particular honey samples, one-factor analysis of variance or the Kruskal-Wallis test was applied, and the correlation between levels of individual metals in the honeys was investigated. Similarities between the honeys with regard to the metal content were determined using Ward’s method of cluster analysis. Among the analyzed nectar honeys from Lower Silesia, the content of zinc was the highest in linden flower honey (13.41 mg kg–1), copper and manganese – in buckwheat (1.50 mg kg–1 and 9.40 mg kg–1, respectively), nickel – in multifloral (1.03 mg kg–1) and buckwheat (1.25 mg kg–1), magnesium – in goldenrod (29.6 mg kg–1) and iron – in linden flower (2.11 mg kg–1) and goldenrod (2.00 mg kg–1) honeys. The content of arsenic, cadmium and lead did not exceed the permissible values, i.e. 0.20, 0.03 and 0.30 mg kg–1. The correlation analysis performed on the concentrations of the metals in the honeys demonstrated that manganese was positively correlated with copper and nickel, while iron corre-

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.

Determination of metal content in honey by atomic absorption and emission spectrometries

Honey contains a variety of metals. Major metals are primarily derived from soil and nectar-producing plants, but consideration also needs to be given to environmental pollution or other anthropogenic sources of metals in honey, especially of Cd, Cr, Cu, Fe, Ni, Pb and Zn, which may present hazards to human health and adversely affect the quality and the safety of honey. This review surveys the literature from the past 15 years on determination of the metal content of honey by atomic absorption and emission spectrometries. It pays particular attention to sample treatment, sample preparation and measurement techniques. It also discusses the suitability of information on the composition of metals in honey for classifying according to botanical and geographical origin or indicating and controlling environmental pollution.

Contents of Some Metals in Honeys from Different Regions in Turkey

Beekeeping is considered one of the most important agricultural activities around the world. Today the total number of bees in the world is estimated to be about 56 million, which produce about 1.2 million tons of honey (Antonescu and Mateescu, 2001). Turkey has important place among the honey producer countries, it is placed the 3rd (for bee hives) and 4th, position among the honey producing countries in the world. In Turkey, there are about 4 million bee hives producing about 74,000 million tons of honeys. Although all regions of Turkey are suitable for apiculture, the Aegean, Black Sea, and Mediterranean regions are considered to be the most important (DIE, 2005). Honey is an important food for humans. Its importance is not only nutritional, but it is also an indicator for environmental pollution (Porrini et al., 2003; Sevimli et al., 1992). Bees fly intensively in a radius of up to 3 km, and for this reason they and their products can serve as bioindicators for the contamination of the area (Bogdanov et al., 2003). A number of authors have used honey bees and/or their products for monitoring environmental pollution (Antonescu and Mateescu, 2001; Devillers et al., 2002; Nanda et al., 2003; Sevimli et al., 1992; Tong et al., 1975; Tuzen, 2002; Uren et al., 1998; Veleminsky et al., 1990). Air and water contain heavy metals from industry and traffic, which can contaminate the bee colonies and their products (Piro and Mutinelli, 2003). High authmobile traffic congestion can lead to the release of the following metals: aluminum, calcium, copper, iron, lead, magnesium, silicon, zinc, barium, cadmium, chromium, nickel, palladium, platinum, and others being emitted as air pollutants (Tong et al., 1975). The aim of this study is to evaluate some metal (Al, Co, Cr, Cu, Fe, Mn, Ni, and Zn) contents of honeys, collected from different regions of Turkey.

Determination of Heavy Metals in Honey in Kahramanmaraş City, Turkey

Heavy metals in honey are of interest not only for quality control, but also for determination environmental contamination. The objective of this work was to determine distribution of the levels of selected heavy metals. Levels of copper (Cu), cadmium (Cd), manganese (Mn), Iron (Fe), magnesium (Mg) and nickel (Ni) in honey samples (21) in Kahramanmaraş region were determined by atomic absorption spectrometer (AAS). The mean values for Cu, Cd, Mn, Fe, and Mg were 0.01, 0.32, 0.03, 0.36 and 10.45 ppm, respectively. Nickel was not detected in honey samples. Kahramanmaraş honey samples were not free of heavy metals but the levels of them were found well below the permitted levels. The results suggested that honey may be useful for assessing the presence of environmental contaminants.

Determination of heavy metals in honey by potentiometric stripping analysis and using a continuous flow methodology

A methodology for the determination of Zn(II), Cd(II) and Pb(II) directly in dissolved honey samples by potentiometric stripping analysis with a flow cell is proposed. Heavy metals in honey are of interest not only for quality control, but can be used also as an environmental indicator. In this work honey samples were collected in different places of Burgos (Spain). Lead (II) and cadmium (II) can be directly determined. It is necessary to avoid the Zn–Cu interference for zinc (II) determination by adding Ga(III) in the adequate concentration, which has been calculated by using an experimental design methodology. The results were compared with inductively coupled mass plasma spectrometry as reference method.

Direct determination of toxic trace metals in honey and sugars using inductively coupled plasma atomic emission spectrometry

A rapid method for the determination of Pb, Cd, Cu, Cr, Co, Ni, Mn and Zn in honey and sugars without prior digestion or ashing of the sample was developed, using inductively coupled plasma atomic emission spectrometry (ICP-AES). The critical instrumental parameters such as sample flow rate and radio frequency incident power were thoroughly optimized. The effect of matrix type and its concentration was also examined for glucose/fructose, sucrose and honey matrices. The sensitivity was investigated using calibration curves obtained in presence of the above matrices. The obtained recoveries for Cd, Cu, Cr, Co, Ni and Mn at the μg l −1 level were satisfactory and practically independent of the matrix used for the calibration standards. The recoveries of Pb and Zn were less sufficient. Various commercial samples of honey, sugar, glucose and fructose were analyzed with respect to their toxic metal content. The method can be applied for routine analysis, quality and environmental pollution control purposes at the μg l −1 level of concentration, after suitable dilution of the samples.

Ion chromatographic and voltammetric determination of heavy and transition metals in honey

Heavy metals in honey are of interest not only for quality control, but can be used also as an environmental indicator. In the present work, in order to minimize sample pre-treatment, the interference by organic constituents of the matrix is overcome by using oxidative UV photolysis. The matrix degrades in less than 1 h, while most common metallic impurities, like iron, copper, nickel, zinc, lead, cadmium and cobalt, remain unaffected by UV radiation, with the exception of manganese. After UV photolysis, the resulting solution is directly analyzed by ion chromatography and differential pulse anodic or cathodic stripping voltammetry. In absence of official standards, the results obtained by these techniques on spiked matrix-matched blank solutions and original and spiked real samples are compared with those of the well established electrothermal atomic absorption spectrometry and they are found in good agreement. The proposed techniques show satisfactory sensitivity, detection limits and standard deviation for heavy and transition metals determination in honey. In addition, both ion chromatography and pulsed voltammetries permit multielement analyses which can be fully automated.

Determination of heavy metals in honey by anodic stripping voltammetry at microelectrodes

A methodology for the determination of Cu, Pb, Cd and Zn by differential pulse anodic stripping voltammetry (DPASV) at Hg microelectrodes in honey samples is proposed. The simultaneous quantification of the four metals in the mineralised matrix is prevented by the formation of Cu–Zn intermetallic species during the deposition step. However, the addition of Ga(III) salt to the measurement solution and the metal deposition at a potential lower than that required for Zn reduction allow the determination of the four metals by two DPASV experiments, consecutively performed on the same sample solution. High levels of repeatability (uncertainty better than 2% for metal concentrations higher than 0.2 μg g −1, independent of the kind of metal) and not significantly biased results make the proposed method accurate. The detection limits, computed by following the procedure suggested by IUPAC, do not show any significant differences from one another, allowing the computation of a common value equal to 0.0123 μg g −1. Although the complete procedure is optimised for the mineralised honey samples, the possibility to obtain speciation information by a direct stripping analysis in raw honey, i.e. a highly viscous real sample, has also been investigated and is discussed.

Content of some trace metals in honey from south-eastern Anatolia

Contents of Na, K, Ca, Mg, Cu, Fe, Mn, Zn and Co in honey (30 samples) from different parts of south-eastern Anatolia (Turkey) were determined by atomic absorption spectrometer AAS. The mean values for Na, K, Ca, Mg, Cu, Fe, Mn, Zn and Co were 118, 296, 51, 33, 1.8, 6.6, 1.0, 2.7 and 1.0 mg/kg, respectively. Also determined in the honey samples were invert sugar, sucrose, hydroxymethyifurfural, diastase activity, free acid, lactone, pH, ash, proline and moisture. In south-eastern Anatolia the honeys were found to have low ash contents, and some high mineral contents. ©

Hydride Generation/Condensation System With an Inductively Coupled Argon Plasma Polychromator for Simultaneous Determination of Arsenic, Antimony, Selenium, Lead, Mercury and Tin in Honey

Abstract An efficient method for the determination of nanogram levels of heavy metals in honey is described. Honey samples obtained in the field from farms located along the coast of the province of Cap-Bon (North Tunisia) were analysed by hydride generation with an inductively coupled argon plasma polychromator after a previous treatment in a microwave acid bomb. An apparatus for the generation of volatile hydrides, interfaced with an inductively coupled argon plasma polychromator for simultaneous determination of As, Pb, Sb, Hg and Sn, is used. The optimum conditions for generating and determining the compounds and the effect of different parameters are discussed. The parameters investigated include: the chemical nature, form and concentration of the reductant, acid concentration of the sample and the carrier gas flow rate. Detection limits range 0.05 ng/ml for Hg to 1.1 ng/ml for Sb and precision values at 10 ng/ml are less than 6% of the relative standard deviation. Analytical protocols concerning ana...

Honey as an indicator of heavy metal contamination

The potential use of honey as an indicator in mineral prospecting and environmental contamination studies has been investigated. Silver, Cd, Cu, and Pb levels are reported in honeys collected throughout the U.K. The elemental content of honeys was investigated in relation to that in the soils collected from within the foraging area. For samples collected over two seasons the following concentrations were found Ag <0.1 to 6.5 ng g−1 (d.w.); Cd <0.3 to 300 ng g−1; Cu 35 to 6510 ng g−1; Pb <2 to 200 ng g−1. Considerable spatial and seasonal fluctuations were apparent. No correlations were observed between honey and soil concentrations for either Cu or Pb. It is concluded that the low concentrations of heavy metals in honey and their inherent variability (due to differences in floral source, foraging range, entrapment of atmospheric particulates on the flower, etc.) detract from the reliable use of honey as a monitoring tool. The relative merits of honeybees, pollen and beeswax for environmental monitoring or biogeochemical prospecting studies are also briefly discussed.