Amperometric determination of the water content in acetone, butter and margarine using a wall-tube platinum microelectrode in a flow injection system

Björefors, Fredrik; Nyholm, Leif; Donten, Mikołaj; Stojek, Zbigniew

doi:10.1039/a806844e

Cited by 10 publications

(8 citation statements)

References 22 publications

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“…As far as literature data are concerned, it should also be mentioned that the biosensors described herein are all original and differ from the biosensor used for example by Mannino et al 23 or those described by other workers. 24 The advantage, as in the present investigation, of using a gaseous diffusion electrode rather than the more common amperometric electrode used by the above workers, is the strong decrease obtained in many interferences, especially when the electrode is used for direct determination in real samples.…”

Section: Discussionmentioning

confidence: 75%

“…Additionally, a further improvement of the precision of the method can probably be obtained by applying the method described here under flow or flow-injection conditions. 24,26 Furthermore, the Karl Fischer method is certainly more tedious and has the disadvantage of requiring highly toxic, expensive and easily perishable reagents. The proposed method involving the use of a biosensor, on the other hand, provides rapid responses, demands only inexpensive apparatus and above all is fast, easy and practical to use.…”

Section: Discussionmentioning

confidence: 99%

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Two OPEEs (organic phase enzyme electrodes) used to check the percentage water content in hydrophobic foods and drugs

Campanella

Santis

Favero

et al. 2001

Analyst

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The development and optimization of an analytical method using enzymatic biosensors able to operate in organic solvents [organic phase enzyme electrodes (OPEEs)] for the determination of the water content in food fats (butter, margarine) or pharmaceutical or cosmetic ointments is described. The method is based on the increase in enzymatic activity which is related to the increase in the percentage water content in the organic phase into which the biosensor is dipped. The enzymes used to assemble the biosensors were tyrosinase or catalase, the substrates were phenol or p-cresol and tert-butyl hydroperoxide, respectively, and the organic solvents were acetonitrile or dioxane. A gas diffusion amperometric electrode for oxygen measurement was used as electrochemical transducer. The results were compared with those obtained applying the Karl Fischer method to the same food or drug matrices. The correlations among the two methods proved satisfactory, as the difference in the computed values of water content was never higher than 7%. Also, the precision of measurements was acceptable (RSD < 6%) in all the analyses of real matrices.

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Section: Discussionmentioning

confidence: 75%

Section: Discussionmentioning

confidence: 99%

Two OPEEs (organic phase enzyme electrodes) used to check the percentage water content in hydrophobic foods and drugs

Campanella

Santis

Favero

et al. 2001

Analyst

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“…Moreover, in spite of the permittivity value (e = 21.5) and moderate conductivity of acetone, scarce electroanalytical use has been made of this solvent. 22 Fig. 1 shows the cyclic voltammogram registered from a 2.0 3 10 25 mol l 21 TBC solution in acetone containing 0.01 mol l 21 NaClO 4 as supporting electrolyte.…”

Section: Resultsmentioning

confidence: 99%

Determination of styrene and styrene additives using cylindrical microelectrodes in acetone

Pérez‐Alonso

Agüı́

Yáñez‐Sedeño

et al. 2000

Analyst

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Cylindrical carbon fibre microelectrodes (CFMEs) (8 mm in diameter, 8 mm in length) were used to develop voltammetric methods for the determination of the antioxidant 4-tert-butylcatechol (TBC) in styrene, and of styrene in polystyrene samples. Acetone, containing 0.01 mol l 21 sodium perchlorate as supporting electrolyte, was selected as a suitable working medium. A good adjustment of the voltammetric responses to that predicted by the theory was found. Reproducible electroanalytical responses were obtained with no need of applying cleaning treatments to the CFME. Using square-wave voltammetry (SWV), linear calibration graphs were obtained for TBC and styrene in the 1.0 3 10 26 -1.0 3 10 24 mol l 21 range, with detection limits of 4.3 3 10 27 mol l 21 and 4.0 3 10 27 mol l 21 , respectively. The sensitivity of the method for styrene was around four orders of magnitude better than that reported for another microelectrode-based electroanalytical method. Voltammograms from mixtures of TBC and styrene showed two well-defined oxidation peaks with a difference between the peak potentials of 600 mV. Commercial styrene samples containing 0.005% of TBC were analyzed with good results. In addition, the method was applied to the determination of styrene in spiked polystyrene yoghurt packagings. Experimental ApparatusVoltammetric measurements were carried out with a BAS (West Lafayette, IN, USA) 100 potentiostat provided with a BAS C2 EF-1080 cell stand and a BAS PA-1 current

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“…The system allows determining coulometrically the quantity of analyte in the flow system without calibration. A platinum 10 m disk in a wall-jet cell was used in amperometric FIA determination of water in acetone, due to the fact that using microelectrodes enables carrying out measurements in media with very low conductivity [96]. It was shown that the steady-state current for water oxidation was independent of the supporting electrolyte concentration and linear response at 2.8 V was obtained for water content from 0.005 to 0.7%.…”

Section: Voltammetric and Amperometric Detection In Flow Analysismentioning

confidence: 98%

Recent developments in electrochemical flow detections—A review

Trojanowicz

2009

Analytica Chimica Acta

129

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Amperometric determination of the water content in acetone, butter and margarine using a wall-tube platinum microelectrode in a flow injection system

Cited by 10 publications

References 22 publications

Two OPEEs (organic phase enzyme electrodes) used to check the percentage water content in hydrophobic foods and drugs

Two OPEEs (organic phase enzyme electrodes) used to check the percentage water content in hydrophobic foods and drugs

Determination of styrene and styrene additives using cylindrical microelectrodes in acetone

Recent developments in electrochemical flow detections—A review

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