scholarly journals Assessment of Heavy Metals and Proximate Analysis of Cocoa Beans from Selected Cocoa Growing Areas in Ghana

Author(s):  
William Asante Nnuro ◽  
Daniel Amankwaah ◽  
Johannes A. M. Awudza ◽  
Samuel Afful

The levels of six selected heavy metals namely: lead (Pb), cadmium (Cd), copper (Cu), manganese (Mn), iron (Fe) and zinc (Zn) have been investigated in cocoa beans sampled from Bekwai, Juaso, Kaspen, Asampaneye and Asamakese, five major cocoa-growing communities in Ghana. Aqua regia digestion procedure was applied for sample digestion and atomic absorption spectroscopy was used for the determination of the metals. The method for the determination of the metals was validated by analyzing standard reference material and levels of metals obtained compared favourably with reported values. Samples were also subjected to proximate analysis by determining moisture, ash, fibre, fat, protein and carbohydrate nutritional compositions of the beans. Method of proximate analysis as reported by Association of analytical chemists (AOAC) was used for estimation of nutritional compositions. Indeed, lead and cadmium concentrations were the lowest in all the samples. The generally high concentrations of Fe, Zn, Cu and Mn in the samples were anticipated as they are regarded essential in living organisms. The mean concentrations expressed in µg/g ranged from 0.013 to 0.042 for Pb, 25.36 to 54.24 for Cd, 36.94 to 58.71 for Zn, 7.12 to 64.65 for Mn and 10.14 to 54.17 for Cu. Proximate analysis of the cocoa beans showed carbohydrate and fat as the nutrients with the dominant composition. Correlation analysis of the metals and nutritional compositions indicated no clear relationship between the levels of the metals and the nutrients.

2020 ◽  
Vol 48 (4) ◽  
pp. 2095-2113
Author(s):  
Radu L. SUMALAN ◽  
Cornelia MUNTEAN ◽  
Ana KOSTOV ◽  
Daniel KRŽANOVIĆ ◽  
Noemi L. JUCSOR ◽  
...  

Heavy metal pollution, manifested by the accumulation, toxicity and persistence in soil, water, air, and living organisms, is a major environmental problem that requires energetic resolution. Mining tailing areas contain metal minerals such as Cu, Zn, Pb, Cr and Cd in high concentrations that pollute the environment and pose threats to human health. Phytoremediation represents a sustainable, long-term, and relatively inexpensive strategy, thus proving to be convenient for stabilizing and improving the environment in former heavy metal-polluted mining sites. This study presents the bioremediation potential of Silphium perfoliatum L. plants, in the vegetative stages of leaf rosette formation, grown on soil polluted with heavy metals from mining dumps in Moldova-Noua, in the Western part of Romania. The bioaccumulation factor (BAF), translocation factor (TF), metal uptake (MU) and removal efficiency (RE) of Cu, Zn, Cr and Pb by S. perfoliatum plants were determined in a potted experiment in controlled environmental conditions. The reference quantities of heavy metals have been determined in the studied soil sample. The experiment followed the dynamics of the translocation and accumulation of heavy metals in the soil, in the various organs of the silphium plants, during the formation of the leaf rosette (13-18 BBCH). The determination of the amount of heavy metals in soil and plants was achieved by the method of digestion with hydrochloric and nitric acid 3/1 (v/v) quantified by atomic absorption spectroscopy (AAS). The obtained experimental results demonstrate that the substrate has a high heavy metal content being at the alert threshold for Zn (260.01 mg kg-1 in substrate compared with alert threshold 300 mg kg-1) and at intervention thresholds for other metals (Cu -234.66 mg kg-1/200 mg kg-1; 299.08 mg kg-1/300 mg kg-1 and Pb-175.18 mg kg-1/100 mg kg-1). The average concentration of the metals determined in dynamics in the dry biomass of plants varied between roots, petioles, and laminas. The root is the main accumulator for Cu and Cr (Cu – 37.32 mg kg-1 -13 BBCH to 43.89 mg kg-1-15 BBCH and 80.71 mg kg-1 – 18 BBCH; Cr – 57.43 mg kg-1 – 13 BBCH to 93.36 mg kg-1 -18 BBCH), and for Zn and Pb the lamina seems to carry the same function. Preliminary results show that Silphium perfoliatum may be a viable alternative in the bioremediation and treatment of heavy metal-contaminated area.


2017 ◽  
Vol 2 (1) ◽  
pp. 39
Author(s):  
Rahmi Nurhaini ◽  
Arief Affandi

Iron (Fe) is one of many heavy metals that is corrosive resistant, dense, and has a low melting point. If accumulated in the body, the metal can cause some medical conditions, such as irritation to skin and eyes, breathing problems, and in the long term, cancer. This research aims to know generally the spread of metallic iron (Fe) in the river Pasar in Belangwetan, Klaten. This study was conducted using an observational method in which researchers did not examine the effects of interventions. Sampling was done using purposive sampling method taken from three points, namely the upper, middle, lower. Determination of iron levels by Atomic Absorption Spectrophotometer (AAS) obtained a positive result, and the data was processed using SPSS to determine the Mean and Standard Deviation. Of the research result, it could be known the Mean score was 2.33 ppm and SD was 0.0352. The result of this research indicated that the levels of iron in the river Pasar in Belangwetan were 2.33 ppm. It means that the levels violate the regulation of the Minister of Health of the Republic of Indonesia, which is not more than 1mg/L (1ppm) in the clean water


2014 ◽  
Vol 4 (1) ◽  
pp. 193 ◽  
Author(s):  
Gideon Ramtahal ◽  
Ivan Chang Yen ◽  
Isaac Bekele ◽  
Frances Bekele ◽  
Lawrence Wilson ◽  
...  

<p>The determination of heavy metals in cocoa beans and chocolates is of great importance, due to increasingly stringent regulations being implemented by international legislative bodies and chocolate manufacturers, to protect the health of their consumers. While various techniques exist for heavy metal analyses in cocoa, this study developed a cost-effective, accurate and precise method capable of processing up to 120 samples per batch for the determination of cadmium, copper, nickel and zinc. For sample extractions, a normal laboratory hot plate and locally fabricated high-capacity digestion blocks were used, instead of dedicated block digestion or microwave digestion systems. In addition, only concentrated nitric acid was used, instead of mixed reagents used in standardized methods, for metal extractions from samples, with a sample: extractant ratio of 0.5 g : 10 mL, digestion at 130 ºC, followed by filtration and analysis by flame atomic absorption spectrophotometry. The method was validated with Certified Reference Materials, with heavy metal recoveries generally &gt;95%. Additionally, an in-house quality control sample of ground cocoa nib analyzed together with the Certified Reference Materials was used to monitor the consistency of analyses of heavy metals in cocoa bean samples.</p>


2006 ◽  
Vol 54 (6-7) ◽  
pp. 307-314 ◽  
Author(s):  
B. Béchet ◽  
B. Durin ◽  
M. Legret ◽  
P. Le Cloirec

The thickness of non-saturated zone and physico-chemical conditions are important parameters to assess the impact of infiltration ponds on water resources with respect to heavy metals transfer. As changes in physico-chemical parameters of solutions have a strong impact on the mobility of colloidal phases in sediments and soils, the colloidal facilitated transfer of heavy metals has to be investigated. Therefore, this study focuses on the characterization of runoff, surface and interstitial waters in a retention/infiltration pond collecting runoff waters of a bridge near Nantes. Physico-chemical parameters and chemical analyses were performed on the waters during about one year. The separation of dissolved and colloidal fractions was carried out by filtration and ultrafiltration for one sample of surface and interstitial waters. Until now, the runoff waters were only filtered at 0.45 μm. The comparison of physico-chemical data shows that the minor variations of runoff water parameters are mitigated in basin and in soils but strong variations impact the composition of interstitial waters. High concentrations of zinc, copper and still of lead are measured in runoff. Lead and cadmium seem to be associated to colloidal and particulate fractions while zinc, copper, nickel and chromium are distributed in all fractions.


2012 ◽  
Vol 5 ◽  
pp. ASWR.S10081 ◽  
Author(s):  
Achour Louhi ◽  
Atika Hammadi ◽  
Mabrouka Achouri

This study was conducted in order to fight against pollution of the environment. The study concerns river sediment of the Seybouse River in northeastern Algeria. Northeastern Algeria is known for its various industries (steel, fertilizer, metal processing, etc), and the sediment deposited by the Seybouse River, is probably polluted by heavy metals. For this study, we used two protocols of digestion of sediments, the first, using a mixture of hydrofluoric acid and perchloric acid, and the second, using aqua regia. The comparison of these two protocols will help us to find the best solubilization and thus facilitate the extraction and determination of heavy metals in sediment. Before determining the concentration of some heavy metals (Fe, Zn, Mn, Sn, Ni, Cr, Pb and Cu), we first analyzed parameters of sediments such as pH and organic matter. We used atomic absorption spectrometry (AAS) to measure these heavy metals. The functional groups characteristic of organic matter and particularly clays were identified by infrared spectroscopy. The average concentrations of metals exceeded acceptable standards for sediment pollution with heavy metals. Maximum concentrations in mg/kg respectively of the elements studied (Fe, Zn, Mn, Sn, Ni, Cr, Pb and Cu) were, respectively, 2460.20 ± 74.8; 1140.65 ± 38.2; 3.60 ± 1.2; 1.20 ± 0.5; 16.80 ± 2.6; 9.50 ± 3.2; 476.31 ± 21.6 and 145.15 ± 35.2. These results clearly show that the sediments deposited by the Seybouse River are heavily polluted.


2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Iva KOTALOVÁ ◽  
Katrin CALÁBKOVÁ ◽  
Martina NOVÁČKOVÁ ◽  
Silvie DRABINOVÁ ◽  
Silvie HEVIÁNKOVÁ

Polychlorinated substances, polyaromatic hydrocarbons, heavy metals and pesticides are among the priority even at low concentrations. The problem, however, is that such low concentrations are impossible to measure using most available methods. This researchfocused on the determination of selected priority substances – heavy metals, namely lead and cadmium, in which the determination ofPb and Cd in wastewater by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was preceded by water sample pre-treatment.The paper deals with the influence of the pre-treatment on the resulting measured values. Two processes were selected as pre-treatmentprocesses. The first pre-treatment procedure was a simple filtration using a filter paper for moderate filtration. As the second procedure, we applied decomposition of the sample by nitric acid in the open system. The pre-treated wastewater samples were subsequentlyexamined using ICP-MS. Based on the obtained results, we can conclude that decomposition of the sample by nitric acid in the opensystem is a more suitable pre-treatment method for water samples


2017 ◽  
Vol 14 (4) ◽  
pp. 1349-1354
Author(s):  
Faten M. Ali Zainy

ABSTRACT: Bleaching cream and cosmetics products of skin have risk of toxicity and deleterious effects to the human health because of their multiplicative contamination with heavy metals and uncertain mixing of different components. Thus, the present study reports a comprehensive study on the trace selected heavy metal (Hg, Cd, Ti, Bi, Pb, As and Tl) determination in 16 samples of bleaching creams and samples mixture of bleaching creams simultaneously to get a double activity (shiny and faster) on the skin from the local market of Saudi Arabia. Samples were digested with high pressure microwave technique followed by direct determination by inductive coupled plasma - optical emission spectrometer (ICP-OES). Hg, Bi, Ti and Pb levels on samples were found equal 5739.16, 7013.53, 21407.73, 456.70 µg/g, respectively whereas other elements (Cd, As and Tl) were found less than 28.99 ppm. One sample of the mixtures showed high concentrations of Hg (13338.50 µg/g,) and Bi (619.23 µg/g). Thus, creams and cream mixtures containing heavy metals above the permissible limit must be blind. The lower detection limits (LOD) were achieved at 2.5-50 µg/g concentration level, RSD was less than 14.72%, and recovery percentage for cosmetics were in the range of 88.52 -99.62%. The proposed method for sample digestion and ICP-OES measurements was fast, precise, convenient and provided good recovery of the tested elements.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
O. Malyshevska ◽  

Biotesting to assess the complex relationships between soil, contaminants and living organisms and to determine the impact on ecosystems of pollutants whose concentrations may be beyond the sensitivity of the methods of determination and the composition of which cannot be determined. The aim is to establish the level of phytoxicity of wastes of mechanical processing of polymer mixtures, which are extracted from solid household waste with the help of indicator plants. Methods. Evaluation of phytotoxic effects was performed by vegetation methods according to ISO: 17402-2008, 17126-2005a, 11269-1: 2012a, 11269-2: 2012b. Contamination levels of the test samples were assessed according to ISO 16198.Objects of research: watercress seeds, mustard, wheat, corn, soybeans, barley and sludge from the processing of polymer mixtures composed of polymer particles of different composition and quantity, along with the remnants of paper labels. Studies of the content of heavy metals (Pb, Cu, Cd, Zn, Ni) were performed by atomic absorption method on a spectrophotometer type CAS-120.1 in accordance with generally accepted methods. Results. The studied sludge does not negatively affect the process of germination of watercress, mustard, corn. The level of phytotoxic effect of sludge on the germination of soybeans and barley was within acceptable limits and did not exceed 3.33%. The study of migration of heavy metals present in the sludge and their accumulation during the growth and development of plants showed their insignificant content regardless of the sludge content. Only the lead content was higher than in the control 2.13 times and 1.83 times higher than in "relatively clean soil". Conclusions. Determination of phytotoxicity of this type of sludge on the process of germination and vegetation changes of plants should be carried out on the most sensitive crops - watercress and mustard. A study of the migration of heavy metals present in the sludge and their accumulation during plant growth showed the presence of bound forms of heavy metals copper, nickel, cadmium and zinc - the migration of which has not been established. However, mobile forms of lead that migrate from the sludge and accumulate in plants have been identified.


2013 ◽  
Vol 39 (2) ◽  
pp. 3-16 ◽  
Author(s):  
Aleksandra Ibragimow ◽  
Barbara Walna ◽  
Marcin Siepak

Abstract The occurrence of heavy metals (Cd, Cr, Cu, Ni, Pb, Zn) has been determined in the fluvial sediment samples collected along three transects in the Middle Odra River (western Poland) with a width of 360 m. The total concentrations of the metals were obtained after HNO3 microwave digestion and the available fractions of heavy metals were determined by single extraction procedures using two extractants: 0.01M CaCl2 and 0.05M EDTA. The measurement of physico-chemical parameters was also performed. The determination of total and available fractions of heavy metals, except potential available fractions of Cr, revealed high concentrations of studied elements detected in the sediment samples characterized by high content of coarse and very coarse-grained sand fraction and high content of organic matter. It was found that the concentrations of total and available fractions of metals could increase along with the content of organic matter, Eh values and concentrations of H+. Apart from the above, those concentrations become the lowest, the higher the content of medium grain size fractions is. Furthermore, the amounts of CaCl2 and EDTA extractable metals increase in the sediments samples characterized by the lowest total and available concentrations of heavy metals.


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