Abstract: Coffee is a widely consumed beverage and is the second most traded commodity globally after petroleum. The aim of this paper is to provide a comprehensive review of the analytical and instrumental methods employed in Ethiopia to determine the concentrations of essential and toxic heavy metals in coffee. Several studies have been conducted to determine the concentrations of these metals in Ethiopian coffee, using various spectroscopic techniques, namely flame atomic absorption spectrometry (FAAS), inductively coupled plasma-optical emission spectroscopy (ICP-OES), inductively coupled plasma-mass spectrometry (ICP-MS), direct mercury analyzer (DMA), particle-induced X-ray emission (PIXE), energy dispersive X-ray fluorescence, inductively coupled plasma (ICP), X-ray fluorescence spectroscopy (XRF), and elemental analyzer-isotope ratio mass spectroscopy. The results of these studies indicate that the concentrations of essential metals such as K, Mg, Fe, Zn, Cu, and Mn were within the permissible limits established by international organizations. Conversely, the concentration of nonessential metals, namely Pb, Cd, and Cr, was either below the detection limits or within the maximum permissible limits set by international organizations. Specifically, the concentration of essential and toxic metals present in coffee beans was found to be within the permissible limits established by international organizations, which is crucial for the nutritional value of coffee as well as the safety of consumers. These findings suggest that Ethiopian coffee is generally safe for human consumption in terms of metal content. Furthermore, significant differences were detected in the elemental composition of coffee samples obtained from different regions of Ethiopia. The elemental composition of coffee samples varies among different regions of Ethiopia. indicate that the geographical origin of coffee may be distinguished based on its elemental profile. This information can be useful for the authentication of the coffee origin, which is a critical aspect of maintaining the quality and authenticity of Ethiopian coffee.Abstract: Coffee is a widely consumed beverage and is the second most traded commodity globally after petroleum. The aim of this paper is to provide a comprehensive review of the analytical and instrumental methods employed in Ethiopia to determine the concentrations of essential and toxic heavy metals in coffee. Several studies have been conducted to determ...Show More
Abstract: Persistent organic pollutants such as pharmaceuticals (iohexol and paracetamol) released into the environment is an environmental problem. Thus our objective is to propose an effective and less expensive method for the determination of their concentrations in the environment. In this work the detection and quantification of pharmaceuticals (iohexol and paracetamol) were performed using cyclic voltammetry and differential pulse voltammetry (DPV). The anode used is a boron-doped diamond electrode (BDD) modified with gold particles (Au-BDD). The characterization of the Au-BDD electrode surface by scanning electron microscopy coupled to energy dispersive spectroscopy and by the electrochemical method (cyclic voltammetry) showed the presence of gold particles uniformly distributed on the anode surface. DPV method allowed to obtain two calibration curves for iohexol and paracetamol concentrations ranging respectively from 4 µM to 67.42 µM and from 0.8 µM to 22.943 µM. The limits of detection are respectively 1.13 µM and 0.045 µM for iohexol and paracetamol. These results show that the presence of gold particles on the anode surface improved the detection of paracetamol. These pharmaceuticals were detected in an ionic environment and it was noted that the interference phenomenon was very negligible during the detection of these two pharmaceuticals. This shows that our anode can be used to determine PCM and IHX concentrations in highly charged media.Abstract: Persistent organic pollutants such as pharmaceuticals (iohexol and paracetamol) released into the environment is an environmental problem. Thus our objective is to propose an effective and less expensive method for the determination of their concentrations in the environment. In this work the detection and quantification of pharmaceuticals (iohexol...Show More
Abstract: Honeybees (Apis mellifera L.) play an important ecological and economic role in the pollination service of crops. Pesticide residues in honey can happen when bees in search nectar and pollen, visit crops that have been treated with various agrochemicals for different reasons. The presence of pollutants in honey can influence honeybee colony performance and devalue its use for human consumption. The aims of this study were to determine pesticide residue levels in honey samples from East Shewa and West Arsi zone and to identify type of pesticides present in honey samples. A total of 24 honey samples were collected from apiaries different localities just after harvesting. Honey samples were analyzed using gas chromatography mass spectrometry. Among different pesticides analyzed in honey samples, Chlorpyrifos was the most frequently detected (16.7%) followed by Endosulfan sulphate (12.5%) and Profenofos (8.3%). The average recoveries of pesticides ranged between 72% and 102.4%, with relative standard deviation less than 20%. All the pesticide residues detected were very low and below their respective maximum residue limits set by the European Union. Hence, pesticide residues in honey samples analyzed do not pose any health risk to consumers. Although the study results showed none significant pesticide residue in the analyzed honey samples, a special precaution should be taken regarding to production of pesticides, their sale, and application in the future.Abstract: Honeybees (Apis mellifera L.) play an important ecological and economic role in the pollination service of crops. Pesticide residues in honey can happen when bees in search nectar and pollen, visit crops that have been treated with various agrochemicals for different reasons. The presence of pollutants in honey can influence honeybee colony perform...Show More