Optimization of the Voltammetric Determination of Arsenic in Foodstuffs

Захарова, Э. А.; Deryabina, V. I.; Слепченко, Г. Б.

doi:10.1007/s10809-005-0129-3

Cited by 11 publications

(6 citation statements)

References 8 publications

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“…The combination of low-cost equipments such as a potentiostat (especially for PSA) and an ultrasonic bath, which is often found at routine laboratories, is very promising to solve other analytical purposes. 25,26,29 …”

Section: Resultsmentioning

confidence: 99%

“…The samples were treated in the presence of concentrated HCl and H 2 O 2 at closed vessels under sonication followed by a boiling water heating step. Previously, ultrasonic baths have been successfully applied for the preparation of environmental, [21][22][23][24][25][26] biological 27,28 and food samples 29,30 and now we propose the combination of ultrasound followed by heating (~100 o C) for coconut water samples treatment for PSA zinc determination.…”

Section: Introductionmentioning

confidence: 99%

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Ultrasound-assisted treatment of coconut water samples for potentiometric stripping determination of zinc

Muñoz¹,

Kolbe²,

Siloto³

et al. 2007

J. Braz. Chem. Soc.

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Este trabalho descreve a utilização da análise por redissolução potenciométrica (PSA) sobre eletrodos de filme de mercúrio para a determinação de zinco em água de coco. Foi desenvolvida metodologia para o tratamento de tais amostras por ultra-som, otimizada para a determinação de zinco total por PSA. Um mililitro de amostra foi tratado com 2 mL da mistura 1:1 (v/v) de HCl concentrado e H 2 O 2 (30% m/v) dentro de frascos fechados (4 mL) em um banho ultrassônico seguido de uma etapa de aquecimento em banho-maria por 15 min. Esta metodologia foi otimizada para a determinação de zinco total e foi validada através de análise direta das amostras por espectrometria de absorção atômica com forno de grafite (GFAAS). O limite de detecção obtido pelo método proposto por PSA foi de 1.35 μg L -1 (aplicando 45 s de pré-concentração). Tentativas para quantificar cobre nas mesmas amostras mostraram que o conteúdo deste metal é menor que o limite de detecção de ambas as técnicas, GFAAS e PSA (0.030 μg L -1 depois de 600 s de pré-concentração) com eletrodos de ouro.This work describes the application of potentiometric stripping analysis (PSA) at mercury film electrodes for zinc determination in coconut water. A sample ultrasound-assisted treatment was developed and optimised for the total zinc determination by PSA. One milliliter of sample was treated with 2 mL of 1:1 (v/v) concentrated HCl and H 2 O 2 (30% m/v) mixture in closed (4 mL) vessels under sonication (in ultrasonic bath), followed by a thermal step (in a boiling bath, for 15 min). This methodology was optimised for total zinc determination and was validated by graphite furnace atomic absorption spectrometry (GFAAS) analysis utilizing the sample without any treatment. The limit of detection obtained by the proposed PSA method was 1.35 μg L -1 (applying 45 s of preconcentration). Attempts to evaluate the amount of copper in the same sample show that the content of this metal is lower than the detection limits of both techniques, GFAAS and PSA (0.030 μg L -1 after 600 s of preconcentration) at gold film electrodes.Keywords: potentiometric stripping analysis, zinc, copper, coconut water, ultrasound-assisted treatment, ultrasonic bath IntroductionCoconut water is a common refreshing drink and has been used as an excellent isotonic in Brazil and other tropical countries.1 Extracted from the coconut endosperm (Cocos nucifera), coconut water has several applications, such as the preservation of sheep preantral follicles in situ, 2 the replacement of the high cost total parenteral nutrition solutions 3 and oral rehydration fluid for gastric and intestinal diseases. Due to this increasing interest on applications of coconut water, more recent contribution for the better understanding of its composition has been reported. 5,6 Santoso et al. 6 described the presence of vitamins, sugar, organic acids, fatty acids, amino acids, fibers, and minerals in coconut (Cocos nucifera). Cytokinins were identified and determined using micellar electrokinetic capillary chromatography after pre...

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Ultrasound-assisted treatment of coconut water samples for potentiometric stripping determination of zinc

Muñoz¹,

Kolbe²,

Siloto³

et al. 2007

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

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“…It is expected that ultrasound will clean electrode surfaces, protecting them from contamination or help to release the analyte from complexing agents. Prominent objects of analysis were blood [66,77,79,80,20], emulsions of different kind [28,76,81,35], sea water [55,82], beverages and foodstuff [33,38,44,49,83], body fluids like urine and saliva [40,73,72], industrial effluents [78], lubricating oil [84], petrol [74] and alloys [70].…”

Section: Applicationsmentioning

confidence: 99%

Stripping Analysis Enhanced by Ultrasound, Electrode Heating and Magnetic Fields

Gründler

2008

CAC

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Stripping analysis is a two-step procedure. In the first step, the analyte is accumulated at an electrode surface either by electrolysis or by adsorption. In the second step, the deposited material is removed, typically by electrolysis. The second step is the source of the analytical signal. Sensitivity of the method mainly depends on the amount of substance which is transferred to the electrode surface during accumulation. The methods reviewed make use of unconventional techniques to enhance efficiency of accumulation. By ultrasound, a combined action of thermal and mechanical impacts, partially with extreme energetic states, causes improvement of analytical results. Heating of electrodes or of a nearelectrode area induces laminar electrolyte flow acting as stirring, combined with increased surface temperature that is helpful to lower kinetic hindrances. Magnetic fields in a cell with arbitrarily increased deposition current enhances convection without additional thermal effects. Most of the techniques reviewed are able to improve the efficiency of stripping analysis much more than could be done by driving classical stirring up to the limits.

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“…There have been many studies applying ultrasound bath in the sample treatment of soils and sediments [28][29][30][31], biological [32][33][34], nutritious [35,36]. However, in the case of forage samples, no study has yet been reported in the literature describing this technique for the extraction and quantification of phenolic acids.…”

Section: Introductionmentioning

confidence: 99%

Use of Ultrasound Bath in the Extraction and Quantification of Ester-Linked Phenolic Acids in Tropical Forages

Santos¹,

Vitor²,

Carneiro³

et al. 2011

AJAC

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A method was developed for the analysis of ester-linked phenolic acids in forage samples using extraction by an ultrasound-assisted treatment and quantification by HPLC with a UV-VIS detector. A reversed-phase C18 column was used for developing the method and the optimal condition was established with isocratic elution using acetonitrile/methanol/H 3 PO 4 pH 2.08 (13:12.5:74.5) as the mobile phase. To reduce the time of sample processing, the extraction of ester-linked phenolic acids was studied using ultrasound bath and the results were then compared with those from an extraction usual using alkaline hydrolysis (20˚C for 24 h). The method was valued through external and internal calibration. Internal calibration using o-coumaric acid as internal standard and m-coumaric acid as surrogate internal standard showed better results. The detection limits were of 0.09 and 0.04 mg·L -1 for p-coumaric and ferulic acids, respectively. The proposed method showed a good linear dynamic range (3.00 -30.00 mg·L -1 ) for the analytes. The usefulness of the method-ology was demonstrated by addition-recovery experiments using forage samples and values were in the 83 to 99% range. The extraction of ester-linked phenolic acids by 120 minutes of ultrasound bath was faster and more reproducible than alkaline hydrolysis (20˚C for 24 h).

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Optimization of the Voltammetric Determination of Arsenic in Foodstuffs

Cited by 11 publications

References 8 publications

Ultrasound-assisted treatment of coconut water samples for potentiometric stripping determination of zinc

Ultrasound-assisted treatment of coconut water samples for potentiometric stripping determination of zinc

Stripping Analysis Enhanced by Ultrasound, Electrode Heating and Magnetic Fields

Use of Ultrasound Bath in the Extraction and Quantification of Ester-Linked Phenolic Acids in Tropical Forages

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