Determination of heavy metals (Pb, Cd, Cu, Zn, Cr) in sedimentary reference materials with IDMS: total concentration and aqua regia soluble portion

1988 ◽  
Vol 332 (6) ◽  
pp. 640-644 ◽  
Author(s):  
Adolf Götz ◽  
Klaus G. Heumann
Keyword(s):  
Heavy Metals ◽  
Reference Materials ◽  
Total Concentration ◽  
Aqua Regia

scholarly journals Cost-effective Method of Analysis for the Determination of Cadmium, Copper, Nickel and Zinc in Cocoa Beans and Chocolates

2014 ◽  
Vol 4 (1) ◽  
pp. 193 ◽  
Author(s):  
Gideon Ramtahal ◽  
Ivan Chang Yen ◽  
Isaac Bekele ◽  
Frances Bekele ◽  
Lawrence Wilson ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Reference Materials ◽  
Certified Reference Materials ◽  
Control Sample ◽  
Cost Effective ◽  
Cocoa Beans ◽  
Copper Nickel ◽  
Flame Atomic Absorption

<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>

scholarly journals Determination of Some Heavy Metal Pollutants in Sediments of the Seybouse River in Annaba, Algeria

2012 ◽  
Vol 5 ◽  
pp. ASWR.S10081 ◽  
Author(s):  
Achour Louhi ◽  
Atika Hammadi ◽  
Mabrouka Achouri
Keyword(s):  
Heavy Metals ◽  
Organic Matter ◽  
River Sediment ◽  
Absorption Spectrometry ◽  
Aqua Regia ◽  
Metal Pollutants ◽  
Metal Processing ◽  
Heavy Metal Pollutants ◽  
Northeastern Algeria

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.

scholarly journals Determination of Heavy Metals and Pesticides in Ginseng Products

2001 ◽  
Vol 84 (3) ◽  
pp. 936-939 ◽  
Author(s):  
Ikhlas A Khan ◽  
James Allgood ◽  
Larry A Walker ◽  
Ehab A Abourashed ◽  
Daniel Schlenk ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Total Concentration ◽  
Herbal Medicines ◽  
Over The Counter ◽  
Contaminant Exposure ◽  
Cadmium Lead ◽  
Contaminant Accumulation ◽  
Persistent Pesticides

Abstract Medicinal plants may carry residuals of environmentally persistent pesticides or assimilate heavy metals in varying degrees. Several factors may influence contaminant accumulation, including species, level and duration of contaminant exposure, and topography. As part of a program for assessment of the quality of herbal medicines, we have analyzed 21 over-the-counter ginseng (Panax ginseng) products in various dosage forms. Chromium, mercury, and arsenic were undetectable above their limits of detection in both liquid and solid samples; while cadmium, lead, and nickel were present in the majority of samples. The chlorinated pesticide levels varied widely. In most samples, the total concentration of pesticides was below 100 ppb; while in 5 samples the total concentration exceeded 100 ppb.

scholarly journals PRELIMINARY ASSESSMENT OF Cd, Cr, Ni, Pb AND Zn LEVELS IN MANGROVE SEDIMENTS OF SACO DO MAMANGUÁ (ILHA GRANDE BAY, RJ)

2013 ◽  
Vol 12 (24) ◽  
pp. 8-14
Author(s):  
Alexandre Andrade CERQUEIRA ◽  
Monica Regina da Costa MARQUES ◽  
Paulo Sérgio Alves SOUZA ◽  
Mario Luiz Gomes SOARES ◽  
Daniel Vidal PEREZ
Keyword(s):  
Heavy Metals ◽  
Sediment Quality ◽  
Chemical Characterization ◽  
Absorption Spectrometry ◽  
Mangrove Sediments ◽  
Aqua Regia ◽  
Physico Chemical ◽  
Environmental Agencies ◽  
Janeiro State

Saco do Mamanguá” is located in Ilha Grande Bay, west coast Rio de Janeiro State and suffers intense pressure degradation, mainly by speculation to build "resorts". The region is extremely vulnerable, given that there are in the region of Ilha Grande bay potentially polluting enterprises, such as mangroves. Samples of surface sediments were collected in “Saco do Mamanguá”. In this region, samples were collected at five sampling points parallel to the shoreline at a distance of approximately 10 m between them. Subsequently dried, sieved and analyzed for physico-chemical characterization and determination of heavy metals: Cd, Cr, Ni, Pb and Zn after digestion with aqua regia assisted by microwave radiation. The metal concentrations were determined by atomic absorption spectrometry with flame. The results showed that the sediments in “Saco do Mamanguá” mangrove presents average levels of Cd, Ni and Pb above the established as criteria for sediment quality by environmental agencies from Canadia and United States of America, demonstrating its vulnerability to contaminants of heavy metals existing in the Bay of Ilha Grande.

scholarly journals Test means for separate and total determination of heavy metals in aqueous media

2019 ◽  
Vol 57 (1) ◽  
pp. 101-114
Author(s):  
Marina K. Gabidulina ◽  
◽  
Sergey Yu. Doronin ◽  
Irina V. Kosyreva ◽  
◽  
...  
Keyword(s):  
Heavy Metals ◽  
Total Concentration ◽  
Aqueous Media ◽  
Natural Fibers ◽  
Polymeric Materials ◽  
Petroleum Products ◽  
Test Methods ◽  
Test Tube ◽  
Silica Gels

The classification of the main indicators of the quality of water bodies is considered. The data on controlled chemical indicators are given (content of dissolved oxygen, suspended solids, phenols, petroleum products, etc.) A list of priority hydrochemical water pollutants and the sources of their pollution are presented. The expediency of determining both individual ions of heavy metals (HM) and their complex (integral) indicators is shown by the example of the sum of HMs. The authors summarized existing data on contemporary test methods used for detection and quantitative measurement of the most prominent HM pollutants of aqueous media, namely – Fe(II), Fe(III), Co(II), Ni(II), Cu(II), Mn(II) and Al(III) ions. Concentration of such HM ions can be evaluated by various test means such as indicator papers, detector tubes and polymer plates etc. The main matrices of the test means are considered: cellulose papers, fabrics from artificial and natural fibers, silica gels, xerogels, polymeric materials, etc. The conditions for immobilization and modification of test means (carrying agent, reagent, surfactant, etc.) and principles of analyte determination using the developed test tools (visual and instrumental assessment of the intensity of staining of test forms, determination of the length of staining or bleaching of test tube zones, etc.), as well as some metrological characteristics (detection limit, range of determined contents, relative errors of definitions, etc.) are shown in this article. Detection limits of studied heavy metal ions in aqueous media that can be achieved with proposed test means are as follows: Fe(II) – (0.005-0.01) mg/l; Fe(III) – 0.1 mg/l; Co(II) – (0.02-0.4) mg/l; Ni(II) – (0.1-10) mg/l; Cu(II) – 0.05 mg/l; Mn(II) – 0.03 mg/l; Al(III) – 0.02 mg/l; total concentration of several HM ions – (0.0005-0.001) mg/l.

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