scholarly journals Quantitative Determination of Heavy Metal Concentrations in Herbal Teas Marketed in Various Countries Including Libya

2017 ◽  
pp. 1-10 ◽  
Author(s):  
M. A. Elbagermi ◽  
A. I. Alajtal ◽  
H. G. M. Edwards
Keyword(s):  
Heavy Metals ◽  
Analytical Procedure ◽  
Certified Reference Materials ◽  
Tea Leaves ◽  
Herbal Tea ◽  
Regulatory Standards ◽  
Control Centre ◽  
Herbal Plants ◽  
Tea Leaf

This study presents the determination of the amount of some heavy metals (Cu, Cr, Ni, Cd, Mn, Fe, Mg and Pb) present in commercial brand herbal tea samples purchased from local markets in Misurata, Libya, by atomic absorption spectroscopy. The validity of the analytical procedure was monitored by analysing certified reference materials obtained from the Food and Drugs Control Centre, Libya. The concentration of Cu, Cr, Ni, Cd, Mn, Fe, Mg and Pb in all the tea leaf samples ranged from 5.141 to 17.1, 0.890 to 3.4, 0.0833 to 2.349, 0.035 to 0.38, 32.01to 89.46, 79.01-167, 91.98 to 213.83 and 0.463 to 0.901 µg g-1, respectively. The concentration of heavy metals in the tea leaves can be arranged in the following order, Mg> Fe> Mn>Cu >Cr> Ni> Pb> Cd. Moreover, it is observed that the concentrations of all the toxic elements tested in the investigated herbal plants are found below the permitted levels specified by the international regulatory standards for the medicinal plants.

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 heavy metals in the soils of tea plantations and in fresh and processed tea leaves: an evaluation of six digestion methods

2016 ◽  
Vol 10 (1) ◽  
Author(s):  
Md. Harunur Rashid ◽  
Zeenath Fardous ◽  
M. Alamgir Zaman Chowdhury ◽  
Md. Khorshed Alam ◽  
Md. Latiful Bari ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Tea Leaves ◽  
Tea Plantations ◽  
Digestion Methods

scholarly journals PENETAPAN KADAR FENOL TOTAL DAN KATEKIN DAUN TEH HITAM DAN EKSTRAK ASETON TEH HITAM DARI TANAMAN CAMELLIA SINENSIS VAR. ASSAMICA

Jurnal Kimia ◽  
2020 ◽  
pp. 43
Author(s):  
N. L. P. V. Paramita ◽  
N. P. T. W. Andari ◽  
N. M. D. Andani ◽  
N. M. P. Susanti
Keyword(s):  
Camellia Sinensis ◽  
Black Tea ◽  
Acetone Extract ◽  
Total Phenol ◽  
Total Phenol Content ◽  
Phenol Content ◽  
Tea Leaves ◽  
Tea Leaf ◽  
Acetone Extracts

Indonesia is quite well known as one of the countries that has tea plantations and uses its own production of tea. As a tea producing country, Indonesia has been able as a tea exporter. The most tea production in Indonesia is black tea product. Black tea products are produced from species Camellia sinensis Var. Assamica which undergoes an enzymatic oxidation process to fresh tea leaves. The most phenolic compounds contained in the black tea leaf are catechins, theaflavins, and thearubigin. The purpose of this study was to determine the phenolic total and catechin content of black tea products and acetone extracts produced by D'wan Tea (DT) and Bali Cahaya Amertha (BCA) plantations which located in Tabanan district, Bali. Determination of total phenol was carried out on black tea leaf products and acetone extract using the Folin-Ciocalteu method compared with gallic acid standards. Determination of catechin content was performed on fresh (before oxidized) tea leaves, black tea leaf products, and acetone extracts using the UV-Vis Spectrophotometry method at a maximum wavelength of 257 nm. The results showed that total phenol content of D'wan Tea black tea products (SDT) and Bali Cahaya Amerta (SBCA) were 1.50 ± 0.02 % mg GAE/g dan 0.97 ± 0.02 % mg GAE/g, respectively. Results of the total phenol content of D'Awan Tea (EADT) black tea acetone extract was 6.92 ± 0.12 % mg GAE/g, while the Bali Cahaya Amerta (EABCA) black tea acetone extract was 7.38 ± 0.07 % mg GAE/g. Catechin content from fresh leaf samples of D'wan Tea (SSDT), SDT, and EADT were 15.30 ± 0.22 % mg/g, 8.37 ± 0.13 % mg/g, and 37.45 ± 0.74 % mg/g. Catechin content of fresh leaf samples of Bali Cahaya Amerta (SSBCA), SBCA, and EABCA were 14.71 ± 0.28 % mg/g, 15.16 ± 0.58 % mg/g, and 35.66 ± 0.89 % mg/g. Total phenol content of DT black tea products is greater than BCA black tea products. DT black tea products appear to have decreased catechins in processing. In the processing of black tea it is necessary to decrease catechins content due to the formation of catechin polymers, namely theaflavin and thearubigin as a determinant of the quality of black tea.   Keywords: black tea, Camellia Sinensis, cathecin, total phenol.

scholarly journals Determination of Some Heavy Metals by Flame Atomic Absorption Spectrometry Before Coprecipitation with Neodymium Hydroxide

2011 ◽  
Vol 94 (3) ◽  
pp. 978-984 ◽  
Author(s):  
Mustafa Soylak ◽  
Nebiye Kizil
Keyword(s):  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Flame Atomic Absorption Spectrometry ◽  
Certified Reference Materials ◽  
Absorption Spectrometry ◽  
Flame Atomic Absorption ◽  
Herbal Plants ◽  
Hydroxide Coprecipitation ◽  
Spinach Leaves

Abstract A procedure is described for the determination of trace amounts of Cd(II), Ni(II), Cu(II), Pb(II), Fe(III), Co(II), and Mn(II) that combines flame atomic absorption spectrometry with neodymium hydroxide coprecipitation. The influences of analytical parameters (amount of neodymium, pH of the model solutions, etc.) that affect quantitative recoveries of the analyte ions were investigated. The effects of concomitant ions were also examined. The detection limits for analytes were found in the range of 0.2–3.3 μg/L. The validation of the presented procedure was controlled by analysis of certified reference materials (National Institute of Standards and Technology 1570a spinach leaves and TMDA 54.4 fortified lake water). The applications of the procedure were performed by the analysis of water, food, and herbal plants from Turkey.

Determination of some heavy metals (Fe, Cu, Zn and Pb) in blood by total reflection X-ray fluorescence

2003 ◽  
Vol 107 ◽  
pp. 203-206 ◽  
Author(s):  
M. Bounakhla ◽  
A. Doukkali ◽  
K. Lalaoui ◽  
H. Aguenaou ◽  
N. Mokhtar ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Total Reflection ◽  
X Ray

Determination of selected heavy metals in tuna fish (Thunnus thynnus)

2013 ◽  
Vol 38 (03) ◽  
Author(s):  
S Mol ◽  
S Karakulak ◽  
S Ulusoy
Keyword(s):  
Heavy Metals ◽  
Thunnus Thynnus ◽  
Tuna Fish
Sign in / Sign up

Export Citation Format

Share Document