Heavy Metals in Black Tea Samples Produced in Turkey

Narin, İbrahim; Çolak, Hakan; Türkoğlu, Orhan; Soylak, Mustafa; Doğan, Mehmet

doi:10.1007/s00128-004-0321-4

Cited by 73 publications

(75 citation statements)

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“…Results for Mn presented in our study are generally comparable to those reported by Chen et al (2009), Colak et al (2005, Dash et al (2008), Narin et al (2004a, Malik et al (2008), McKenzie et al (2010) and Nookabkaew et al (2006). Concentrations of Fe in slim teas are very similar to those obtained by Aksuner et al (2012), Colak et al (2005), Kara (2009) andMcKenzie et al (2010), but higher than those determined by Chen et al (2009), Matsuura et al (2001 and Narin et al (2004b).…”

Section: −1supporting

confidence: 90%

“…Xie et al (1998) reported the range of Ba and Sr concentrations in Chinese tea samples as 3.0-42 and 3.5-24 μg g −1 , respectively. Our results for Ni are lower than those observed by Colak et al (2005) and Narin et al (2004a), but are in a good accordance with those reported by Aksuner et al (2012), Malik et al (2008), Seenivasan et al (2008) and Soylak et al (2007). Concentrations of Pb are very similar to those determined by Chen et al (2009) and Mierzwa et al (1998), but slightly higher than these reported by Dash et al (2008), Matsuura et al (2001), Narin et al (2004b) and Seenivasan et al (2008).…”

Section: −1supporting

confidence: 90%

“…The level of Cr in slim teas is generally lower than that published in the relevant literature. The concentration range of Cr in tea commonly ranges from 1.7 to 16.9 μg g −1 (Dash et al 2008;Narin et al 2004a;Seenivasan et al 2008). In case of Cd, our results were lower than those previously reported by Narin et al (2004a) and Salahinejad and Aflaki (2010), but in a quite good agreement with those observed by Seenivasan et al (2008).…”

Section: −1supporting

confidence: 84%

“…Narin et al (2004a) compared two different digestion procedures, i.e., hot-plate heating and microwave-assisted decompositions with a mixture of concentrated HNO 3 and HCl solutions (3:1, v/v), to determine concentrations of Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn in black teas by FAAS and ICP OES. Aksuner et al (2012) examined a microwave-assisted digestion procedure in a mixture of concentrated HNO 3 and H 2 O 2 solutions (3+1 ml) and a hot-plate heating digestion procedure in a mixture of concentrated HNO 3 and HClO 4 solutions (7+8 ml) for the determination of Cu, Fe, K, Mn, Ni and Zn in black, green, white and herbal tea samples by FAAS.…”

Section: Introductionmentioning

confidence: 99%

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Simple and Fast Sample Preparation Procedure Prior to Multi-element Analysis of Slim Teas by ICP OES

2014

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The knowledge about mineral content of slim teas is of great importance since the consumption of these beverages has rapidly increased for the past several years. An increasing popularity of these tea products is mainly attributed to their nutritional properties, flavor, taste and health effects. Therefore, the main goal of the present work was to develop a precise and accurate method of the multi-element analysis of slim teas by inductively coupled plasma optical emission spectrometry (ICP OES) without the need for a laborious and tedious sample treatment preceding spectrometric measurements. Five sample preparation procedures, i.e., the total decomposition in a mixture of HNO 3 and H 2 O 2 solutions using closed vessel microwave-assisted or open vessel hot-plate systems, the solubilisation in aqua regia or a tetramethyl ammonium hydroxide solution and the extraction in a diluted HNO 3 solution, were compared. The performance of the compared procedures was determined in terms of the precision and the accuracy of results achieved and limits of detection of elements. It was found that the solubilisation in aqua regia gave the best results, i.e., limits of detection between 0.15 and 98.4 ng l −1 , the precision within 0.6−3.0 % and the accuracy better than 5 %. The developed method of the analysis, being a useful alternative to timeconsuming wet digestion procedures, was successfully applied to the analysis of five slim tea products.

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Section: −1supporting

confidence: 90%

Section: −1supporting

confidence: 90%

Section: −1supporting

confidence: 84%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Simple and Fast Sample Preparation Procedure Prior to Multi-element Analysis of Slim Teas by ICP OES

2014

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“…[2][3][4][5][6] In most of the previous studies, metal complexes were collected on activated carbon as a filter. Then, the preconcentrated trace metals on the filter were recovered by treating with suitable solvents, such as nitric acid.…”

mentioning

confidence: 99%

On-line Preconcentration System for Lead(II) Determination in Waste Water by Atomic Absorption Spectrometry Using Active Carbon Loaded with Pyrogallol Red

2003

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The determination of trace amounts of lead in environmental samples is currently of great importance due to their high toxicity, accumulative and persistent character in the environment and living organisms. Thus, there is great interest concerning the implementation of a reliable preconcentration system for lead(II) for analytical determinations. At the moment, one of the most used matrix removal preconcentration methods is the on-line retention of the analyte on an adequate solid support by using microcolumns in a flow system, based on mass transfer between a liquid phase and a solid one. 1 These preconcentration systems can be on-line coupled to several atomic detection techniques.Flame atomic absorption spectrometry (FAAS) is a simple and very available technique for the determination of heavy metals in water samples. However, the main problem is a low sensitivity for trace metal at the ng/ml level. This limitation can be overcome by using a preconcentration procedure.Solid-phase extraction (SPE) techniques have found increasing applications for the preconcentration of trace metal ions and the elimination of matrix interference prior to an AAS analysis. Activated carbon is one of the sorbent materials that have been used as collectors for trace elements.2-4 Solid-phase extraction procedures based on the sorption of metal complexes on activated carbon have been widely applied. [2][3][4][5][6] In most of the previous studies, metal complexes were collected on activated carbon as a filter. Then, the preconcentrated trace metals on the filter were recovered by treating with suitable solvents, such as nitric acid. Thus, the prepared activated carbon filter was used only for one analysis. Several complexing agents have been used in the adsorption process on activated carbon, including dithiozone, 7 dithiocarbamate derivatives, 8,9 1-(2-pyridylazo)2-naphthol, 10,11 resorcinol derivatives, 12 1-nitrous-2-naphtol, 13 o,o-diethyldithiophosphate 14,15 and pyrocatechol violet. 16 In all of these methods, a ligand solution was needed for each experiment, because, the chelating agent was used to wash metal ions from the surface of sorbent.In this paper, a new on-line column separationpreconcentration method is described for the determination of Pb(II) by using active carbon loaded with Pyrogallol Red (PGR) and FAAS. Active carbon tightly adsorbed Pyrogallol Red and thus the adsorbed Pyrogallol Red did not wash away with the washing solution that was used to remove lead(II) ions from the column. Automation of the procedure can possibly reduce the risk of operational errors, increase the precision of the method and accelerate the sample throughput. 17 Experimental Reagents and chemicalsAll solutions were prepared with doubly distilled water, unless otherwise stated. A Pyrogallol Red (PGR) solution was prepared by dissolving a suitable amount of PGR (Merck) in a water/ethanol (50:50 v/v) mixture. A buffer solution (0.1 M) was prepared by adding an appropriate amount of NaOH to a potassium hydrogen phthalate solution for pH 3...

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Comparison of Sample Preparation Procedures for the Determination of Trace Heavy Metals in House Dust, Tobacco and Tea Samples by Atomic Absorption Spectrometry

2004

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The effect of wet ashing, dry ashing and microwave procedure for the determination of trace metal levels was investigated in house dust, tobacco and tea samples by atomic absorption spectrometry. The study of sample preparation procedures showed that the microwave method was the best. The recovery of trace metals was very good and precision and accuracy were compatible with standard reference material. The relative standard deviations for all measured metal concentrations were lower than 10%. The digestions of HNO3/H2SO4/HClO4 (4: 1: 1) mixture for house dust, HNO3/H2SO4/H2O2 (2: 2: 2) mixture for tea and HNO3/H2O2 (4: 2) mixture for tobacco were very efficient.

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Heavy Metals in Black Tea Samples Produced in Turkey

Cited by 73 publications

References 0 publications

Simple and Fast Sample Preparation Procedure Prior to Multi-element Analysis of Slim Teas by ICP OES

Simple and Fast Sample Preparation Procedure Prior to Multi-element Analysis of Slim Teas by ICP OES

On-line Preconcentration System for Lead(II) Determination in Waste Water by Atomic Absorption Spectrometry Using Active Carbon Loaded with Pyrogallol Red

Comparison of Sample Preparation Procedures for the Determination of Trace Heavy Metals in House Dust, Tobacco and Tea Samples by Atomic Absorption Spectrometry

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