scholarly journals Analysis of the bioavailability of Cr(III) and Cr(VI) based on the determination of chromium in Mentha piperita by graphite furnace atomic absorption spectrometry

2011 ◽  
Vol 76 (1) ◽  
pp. 143-153 ◽  
Author(s):  
Svetlana Djogo ◽  
Slavica Razic ◽  
Dragan Manojlovic ◽  
Latinka Slavkovic

Mentha piperita L. (Lamiace) was cultivated under the controlled laboratory conditions in the presence of varying levels of trivalent and hexavalent chromium in order to determine its capacity to control chromium uptake and its tolerance limit. The plants were grown in pots at 25?C with controlled soil moisture (about 80 % of the water retention capacity). The soil was treated with increasing concentrations of Cr(NO3)3 (40, 80, 120, and 200 mg kg-1) and K2Cr2O7 (2.5, 5, 10, and 15 mg kg-1). A control group of plants was grown without the addition of chromium to the soil. For each concentration, three acidity levels were tested: natural, one pH unit below and one above the natural acidity of the soil (pH2 = 6, pH1 = 5 and pH3 = 7). The plant samples were digested according to the standard procedure and chromium content was determined by GFAAS. For all plants, the transportation index was calculated and the results (expressed in mg kg-1) at pH1, pH2 and pH3, respectively, were: 0.21-0.80, 0.06-1.06 and 0.04-0.52. The recoveries were good (72.73-115.3 %) as evidenced by the analysis of certified reference materials (NIST SRM 8433 - Corn Bran and NIST SRM 1547 - Peach Leaves). The mobility of chromium through the plants tissues is discussed in regard to its competition with iron and manganese for transport binding sites; hence Mn and Fe were also determined.

2012 ◽  
Vol 56 (4) ◽  
pp. 585-589 ◽  
Author(s):  
Agnieszka Nawrocka ◽  
Józef Szkoda

Abstract Procedure for determination of chromium in biological materials by Zeeman graphite furnace atomic absorption spectrometry method using a Perkin-Elmer spectrometer equipped with hollow-cathode lamp at 357.9 nm was developed. The samples of animal tissues, food, and feed were digested in muffle furnace at 450ºC. The ash was dissolved in 1 N hydrochloric acid and the final solution was diluted in 0.2% nitric acid. Magnesium nitrate (1%) was used as a matrix modifier. The method was validated in terms of basic analytical parameters. The mean recoveries of chromium was 84.4% for muscle, 79.0% for canned meat, and 80.2% for feed, and analytical detection limit was 0.003 μg/g. Certified reference materials were used for analytical quality assurance. The proposed analytical procedure is well adapted for monitoring chromium content in food and feedstuffs. Content of total chromium in the tested samples (animal muscles and liver) was low and was situated in the range of 0.031-0.101 mg/kg (muscles) and 0.047-0.052 mg/kg (liver).


2002 ◽  
Vol 85 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Ignacio López-García ◽  
Mateo Sánchez-Merlos ◽  
Jesús Arroyo-Cortez ◽  
Manuel Hernández-Córdoba

Abstract An electrothermal atomic absorption spectrometric procedure was developed for the determination of mercury in sewage sludge, in which the samples were suspended in a solution containing hydrofluoric and nitric acids. Silver nitrate (4%, m/v) and potassium permanganate (3%, m/v) were incorporated as matrix modifiers, and aliquots were directly introduced into the graphite furnace. A fast-heating program with no conventional pyrolysis step was used. The detection limit for mercury in a 50 mg/mL suspension was 0.1 μg/g. Calibration was performed by using aqueous standards. An analysis of certified reference materials confirmed the reliability of the procedure.


2021 ◽  
Vol 11 (12) ◽  
pp. 5493
Author(s):  
Andrzej Gawor ◽  
Andrii Tupys ◽  
Anna Ruszczyńska ◽  
Ewa Bulska

Nowadays growing attention is paid to the control of fluorine content in samples of biological origin as it is present in the form of various biologically active organic compounds. Due to the chemically-rich matrix of biological tissues, the determination of fluorine becomes a very difficult task. Furthermore, a required complex sample preparation procedure makes the determination of the low contents of F by ion chromatography UV-Vis or ion-selective electrodes not possible. High-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS) seems to be the best option for this purpose due to its high robustness to matrix interferences, especially in the presence of carefully selected modifiers. In this work the possibility of quantitative F determination in water and animal tissues was examined by measuring the molecular absorption of gallium monofluoride (GaF) at 211.248 nm with the use of a commercially available HR-CS GF MAS system. Experimental conditions for the sensitive and precise determination of fluorine were optimized, including the time/temperature program as well as addition of gallium and modifier mixture in combined mode. Under these conditions the fluoride present in the sample was stabilized up to 600 °C, and the optimum vaporization temperature for GaF was 1540 °C. Palladium and zirconium deposited onto the graphite surface served as solid modifiers; sodium acetate and ruthenium modifiers were added directly to the sample. The limit of detection and the characteristic mass of the method were 0.43 μg/L and 8.7 pg, respectively. The proposed procedure was validated by the use of certified reference materials (CRMs) of lake water and animal tissue; the acceptable recovery was obtained, proving that it can be applied for samples with a similar matrix.


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