Characterization of honey from the Canary Islands: determination of the mineral content by atomic absorption spectrophotometry

Neste trabalho, amostras de mel produzidas em três diferentes regiões climáticas do Sudoeste da Bahia, Brasil (semi-árido, Mata Atlântica e Zona de Transição Climática) foram caracterizadas com base nos teores de minerais, elementos traços, cinzas e condutividade elétrica. Os metais foram determinados por espectrometria de absorção atômica. Com a finalidade de avaliar as variáveis químicas capazes de promover uma caracterização do mel produzido em cada região, as técnicas de cluster e componentes principais (ACP) foram aplicadas nos resultados das análises. Com base nas análises de cluster e ACP, foi possível distinguir os diferentes grupos de amostras correspondentes às três origens geográficas dos méis. A elevada correlação observada entre a condutividade elétrica e Cu nas amostras das zonas de transição climática, sugere que essas variáveis estão associadas, e esse fato pode ser atribuído ao uso de cobre na cafeicultura que é a principal atividade agrícola desenvolvida nessa região.In this study, samples of honey produced in three different regional climates in the southwest Bahia, Brazil (semi-arid, Atlantic and Transitional Forest Zones) were characterized on the basis of their mineral and trace elements, ash content and electrical conductivity. The metals were determined by atomic absorption spectrophotometry. The cluster and principal component analysis (PCA) methods were applied to the chemical concentration data in order to study the chemistry variables capable of promoting a characterization of the honey produced in each area. Cluster analysis and PCA distinguishes the different groups of honey samples corresponding to each region of the three geographical origins. The high correlation between electrical conductivity and Cu observed in honey samples from transitional forest zones suggested a coupling to the nutrient cycle, and can be attributed to use of copper compounds in coffee production, a major activity developed in all transitional forest zones.

mentioning

confidence: 99%

Honey classification from semi-arid, Atlantic and transitional forest zones in Bahia, Brazil

Santos¹,

Santos²,

Santos³

et al. 2008

“…[1][2][3][4][5] Both elements are quite often determined in this matrix using air-acetylene flame atomic absorption spectrometry (FAAS), however, due to the complexity of the samples, i.e., the very high content of the monosaccharides, the easily ionized elements like K and Na, phosphates and the other anions, their measurements with the aid of FAAS may encounter some problems related to the matrix effects. 6 In reference to the possibility of the routine analyses and the quality and food safety control measurements of honey, the selection of a suitable procedure for the sample treatment is of a special importance in this case because it decides about the time of the analysis and the dependability of the results.…”

Section: Introductionmentioning

confidence: 99%

“…The subsequent stages of these procedures can additionally be responsible for losses (by the sample overheating and sputtering) or gains (by the contamination from the reagents and the vessels) of the elements. 6 The direct analysis of honey on the content of Ca and Mg, predated by the dilution of the respective samples in water or diluted solutions of the oxidizing reagents (HNO 3 mostly, H 2 O 2 ) and the aspiration of the resulting solutions into FAAS, is less frequent due to profound matrix effects originating from the presence of fructose and glucose in addition to the mineral elements like P or S. Although this method seems to be straightforward, a series of dilutions has to be done for each honey in order to assure that the selected content of honey in the analyzed solutions and the constituents that could potentially interfere with the Ca and Mg measurements would not affect the analytical response for these elements in FAAS. 3,4,[14][15][16] What is more, although the 2-5% (m/v) honey solutions can directly be measured by FAAS, the load of the organic matter and the main mineral constituents in the solutions of such untreated samples may still be high.…”

Section: Introductionmentioning

confidence: 99%

Fast and interference free determination of calcium and magnesium in honeys by solid phase extraction followed by flame atomic absorption spectrometry

Pohl

Stecka

2012

Um procedimento para preparo de amostras, baseado na extração em fase sólida e eluição em duas etapas foi desenvolvido para a determinação da concentração total de Ca e Mg em méis de abelha. As amostras de mel foram tratadas como segue: soluções de amostra (50 mL) a 5,0% (m/v) foram passados a uma vazão de 20 mL min -1 , através de resina Dowex 50W×8-400, para reter íons Ca(II) e Mg(II) e separá-los da matriz contendo glicose e frutose, e dos minerais aniônicos. Depois, 20 mL de uma solução de HNO 3 0,5 mol L -1 foram usados para remover os íons K e Na. Finalmente, Ca e Mg foram eluídos com 5 mL de solução de HCl 2,0 mol L -1 antes da medida de suas concentrações por espectrometria de absorção atômica em chama (FAAS). O procedimento proposto para o preparo da amostra foi rápido (30 min) e permitiu medir as concentrações de Ca e Mg em mel, com precisão de 1-5% e exatidão de 1-3%. Os limites de detecção de 24 ng g -1 de Ca e 4,4 ng g -1 de Mg foram obtidos para FAAS com este procedimento.A sample preparation procedure based on the solid phase extraction and the two-step elution was developed for the determination of the total concentrations of Ca and Mg in bee honeys. The honey samples were treated as follows: the 5.0% (m/v) sample solutions (50 mL) were passed at the flow rate of 20 mL min -1 through the resin beds of Dowex 50W×8-400 to retain the Ca(II) and Mg(II) ions and separate them from the matrix of glucose and fructose in addition to the anionic minerals. Afterwards, 20 mL of a 0.5 mol L -1 HNO 3 solution was used to remove the K and Na ions. Finally, Ca and Mg were eluted prior to the measurements of their concentrations by flame atomic absorption spectrometry (FAAS) using 5 mL of a 2.0 mol L -1 HCl solution. The proposed sample preparation procedure was fast (30 min) and enabled to measure the concentrations of Ca and Mg in honey with the precision of 1-5% and the accuracy of 1-3%. The limits of detection of 24 ng g -1 of Ca and 4.4 ng g -1 of Mg were obtained for FAAS with this procedure.

“…[3][4][5][6][7][8][9] Because Li, like other alkaline or alkaline earth metals present in honey, is associated with soil characteristics and specificity, and agricultural practices, it certainly well reflects geographical origin and different locality conditions. [4][5][6] Accordingly, Li was recognized to be a useful feature accounting for successful discrimination between honeys from different regions, i.e., coastal and mountain territories, rural and urban areas.…”

Section: Introductionmentioning

confidence: 99%

“…[1][2][3][4][5][6] Flame optical emission spectrometry (FOES), although more inexpensive than ICP OES is curiously rarely used. [7][8][9][10] In case of both mentioned techniques, samples of honey are usually calcined, followed by dissolving resulted ash in solutions of mineral acids [3][4][5][6] or digested in concentrated oxidizing reagents 1,2 before measuring Li concentrations.…”

Section: Introductionmentioning

confidence: 99%

Pre-concentration of lithium prior to its determination in honey by flame optical emission spectrometry

Stecka¹,

Pohl²

2011

Foi proposto um procedimento para a pré-concentração e determinação de traços de lítio em diferentes méis florais, empregando para a extração contínua em fase sólida uma resina de troca catiônica fortemente ácida, a Dowex 50W×8-200. Ao se eluir as soluções de méis a 10% em massa, na coluna empacotada com a resina de troca catiônica, os íons Li + , K + e Na + foram retidos na resina enquanto que os açúcares simples não foram retidos e se encontraram integralmente nos eluatos. Os cátions Li + , Na + e K + foram eluídos com uma solução de HCl 1,0 mol L -1 após a lavagem das colunas com água; os analitos presentes nesse eluato foram determinados por espectrometria de emissão ótica com chama (FOES). O limite de detecção instrumental (LOD) apresentado pelo método foi de 0,05 ng g -1 de lítio e o método foi empregado para a quantificação de Li em diversos méis naturais e comerciais. A faixa de concentração ótima para a determinação de Li foi de 0,4 a 5,3 ng g -1 com precisão de 8-11%. A exatidão do método proposto foi avaliada por estudos de recuperação do analito e está no intervalo de 98 a 106%, demonstrando a confiabilidade dos resultados obtidos.A procedure based on solid phase extraction with a strongly acidic cation-exchanger Dowex 50W×8-200 was proposed to pre-concentrate and determine ultra-traces of Li in different floral honeys. When loading 10% (m/v) honey solutions onto columns packed with the cation-exchanger, Li + ions were retained on the resin along with K + and Na + , while simple sugars were passed through columns and were entirely found in effluents. In turn, columns were washed with water and eluted with a 1.0 mol L -1 HCl solution to strip Li + that was subsequently determined in respective eluates by flame optical emission spectrometry (FOES). The proposed method was characterized by a limit of detection (LOD) of 0.05 ng g -1 of Li and later used for analysis of several raw and commercial mono-and multi-flower honeys. It enabled to determine from 0.4 to 5.3 ng g -1 of Li with precision being within 8-11%. Accuracy of this sample pre-treatment procedure and analysis method was assessed applying spike recovery tests. Recoveries of added Li were found to be within 98 to 106%, demonstrating trustworthiness of results achieved.