Análisis de algunos aspectos físicos, químicos y microbiológicos de las muestras de miel producidas y consumidas en Turquía

Analysis of honey produced in the western part of Turkey was carried out in this study. Fifty honey samples, collected from the local market in this region were analyzed for their physicochemical parameters including hydroxymethylfurfural (HMF), electrical conductivity, sucrose, free acidity, moisture and water insoluble impurities, in addition to pathogenic microorganisms present. HMF amounts determined in 47 samples were found to be between 1.9 and 98.0 mg/kg with good reproducibilities (%RSD: 3.2% or better). There were no pathogenic microorganisms in any of the investigated samples. Electrical conductivity that gives information about their mineral contents was measured, and the mean value was found to be 0.33 mS/cm (N=34). In general, most of the samples were considered to meet the requirements of Turkish Food Codex and European Commission Directives.En este estudio se analizó muestras de miel producida en la zona oeste de Turquía. Se trabajó con 50 muestras del mercado local de la región, en las cuales se determinaron parámetros físico-químicos incluyendo el hidroximetilfurfural (HMF), conductividad eléctrica, sacarosa, acidez libre, humedad e impurezas insolubles en agua además de microorganismos patógenos presentes. Las cantidades de HMF determinadas en 47 muestras oscilaron entre 1,9 y 98,0 mg/kg con buena desviación estándar de la reproducibilidad (% de RSD/DSR 3,2% o mejor). No se encontraron microorganismos patógenos en ninguna de las muestras analizadas. La conductividad eléctrica, que aporta información sobre el contenido mineral, resulta en un promedio de 0,33 mS/cm (N=34). En general se encontró que la mayoría de las muestras cumple los requerimientos del Codex alimentario turco y de las directivas de la Comisión Europea.Fil: Bakirdere, Sezgin. Universidad Técnica de Yıldız (Turquía)Fil: Yaroglu, Tolga. Universidad de Ankara (Turquía)Fil: Tirik, Nihan. Ondokuz Mayıs University (Turquía)Fil: Demiroz, Mehmet. Uludag University (Turquía)Fil: Karaca, Abdullah. Fırat University (Turquía

Determination of lead, cadmium and copper in roadside soil and plants in Elazig, Turkey

The concentrations of lead, cadmium and copper in roadside soil and plants in Elazig, Turkey were investigated. Soil samples were collected at distances of 0, 25 and 50 m from the roadside. The concentrations of lead, cadmium and copper were measured by Flame Atomic Absorption Spectrophotometry (FAAS). A slotted tube atom trap ( STAT) was used to increase the sensitivity of lead and cadmium in FAAS. Lead concentrations in soil samples varied from 1.3 to 45 mg kg(-1) while mean lead levels in plants ranged from 120 ng g(-1) for grape in point-4 to 866 ng g(-1) for apple leaves in point-2. Lead analyses showed that there was a considerable contamination in both soil and plants affected from traffic intensity. Overall level of Cd in soil samples lies between 78 and 527 ng/g while cadmium concentration in different vegetations varied in the range of 0.8-98.0 ng g(-1). Concentrations of copper in soil and plant samples were found in the range of 11.1-27.9 mg kg(-1) for soil and 0.8-5.6 mg kg(-1) for plants. Standard reference material (SRM) was used to find the accuracy of the results of soil analyses

From mg/kg to pg/kg levels: A story of trace element determination: A review

Determination of the trace elements in a variety of environmental samples is of great importance. Most elements, including iron, calcium, and selenium, are crucial for the regulation of human mechanisms, and many others, like lead and cadmium, are toxic even at trace levels. Some elements, like selenium, have a narrow margin of safety. Hence, determination of elements at trace levels is crucial in any matrix related to humans. Trace element determination requires sufficiently sensitive procedures to monitor trace levels. This review aims to highlight not only the development in instrumentation for ultratrace element determination in variety of matrices but the application of developed techniques. Advantages and disadvantages of the techniques are also discussed. Copyright © Taylor &Francis Group, LLC

A new microextraction method for trace nickel determination in green tea samples: Solventless dispersion based dispersive liquid-liquid microextraction combined with slotted quartz tube-flame atomic absorption spectrophotometry

In this study, a simple and novel analytical approach was developed in order to determine nickel at trace levels. For this purpose, a dispersive liquid-liquid microextraction (DLLME) method based on solventless dispersion of extraction solvent was developed to separate/preconcentrate nickel from aqueous solution. Combination of the DLLME method with slotted quartz tube-flame atomic absorption spectrophotometry (SQT-FAAS) lowered the analyte's detection limit. In the DLLME method, the extraction solvent was dispersed into aqueous solution by generating fine droplets through air assisted spraying in order to reduce organic solvent consumption and avoid relative error by reducing multiple operation steps. Complexation of nickel(II) was done by using a Schiff Base synthesized from the reaction between 3,5- dibromosalicylaldehyde and 2-aminophenol. All experimental parameters were optimized comprehensively by the step-by-step approach in order to determine optimum conditions to get maximum absorbance values. Under the optimum conditions, analytical performance values were examined, and limit of detection values were obtained as 286 ng mL-1 for FAAS, 137 ng mL-1 for SQT-FAAS, 7.9 ng mL-1 for DLLME-FAAS and 3.9 ng mL-1 for DLLME-SQT-FAAS. The enhancement in detection power was obtained as 82-folds over the detection limit of the conventional FAAS system. Chinese green tea sample was used in recovery studies to check applicability and accuracy of the developed method. Recovery results were close to 100 % with low standard deviation values (n = 4) and this showed that the method appropriate for the selected matrix

Trace level determination of beryllium in natural and flavored mineral waters after pre-concentration using activated carbon

The concentrations of beryllium (Be) in natural and flavored mineral water samples were determined by flame atomic absorption spectrophotometer (FAAS) after pre-concentration based on the complexation of Be(+2) with a mixture of acetylacetone (pentane-2,4-dione) plus morin (3,5,7,2',4'-pentaoxyflavone) and adsorption on activated carbon. The adsorbed complex was eluted with 1.5 ml of 2.0 M HNO(3) and evaporated to dryness. After adding 1.5 ml of 2 M HNO(3) and centrifuging, Be in acid solution was determined by FAAS. To remove a number of metals present in water, EDTA was used as a chelating agent. Beryllium in mineral water samples was pre-concentrated by 500-fold, taking 750 ml as initial sample and 1.5 ml as the final volume. The relative standard deviations were sufficiently low for practical purposes and recoveries were up to 85%. Spiking experiments were performed in real samples to establish accuracy and recoveries. The limits of detection and quantification were 0.01 and 0.03 ng ml(-1), respectively. Twenty samples were analyzed for their beryllium content using optimum parameters. The highest concentration of beryllium was found to be 0.94 +/- 0.15 ng ml(-1) in a natural mineral water, while beryllium was not detected in five samples