Electrochemical detection food analysis

MD Lucock, M Green, R Hartley, MI Levene. Physicochemical and biological factors influencing methylfolate stability use of dithiothreitol for HPLC analysis with electrochemical detection. Food Chem 47 79-86, 1993. 

HJ Kim, YG Park, KY Kim. Analysis of sulfites in foods by ion exclusion with electrochemical detection. Food Technol41 85—91, 1987. 

Knowledge of the identity of phenolic compounds in food facilitates the analysis and discussion of potential antioxidant effects. Thus studies of phenolic compounds as antioxidants in food should usually by accompanied by the identification and quantification of the phenols. Reversed-phase HPLC combined with UV-VIS or electrochemical detection is the most common method for quantification of individual flavonoids and phenolic acids in foods (Merken and Beecher, 2000 Mattila and Kumpulainen, 2002), whereas HPLC combined with mass spectrometry has been used for identification of phenolic compounds (Justesen et al, 1998). Normal-phase HPLC combined with mass spectrometry has been used to identify monomeric and dimeric proanthocyanidins (Lazarus et al, 1999). Flavonoids are usually quantified as aglycones by HPLC, and samples containing flavonoid glycosides are therefore hydrolysed before analysis (Nuutila et al, 2002). 

Vitamin D2 and D3 exhibit identical UV absorption spectra and they do not possess fluorescence. Electrochemical detection is limited and only few methods are applied in food analysis [530,533], MS detection has been applied achieving satisfactory detection limit (10 mol/mL) [534,535],... 

E Le Fur, PX Etievant, JM Meunier. Interest of pulsed electrochemical detection for the analysis of flavor-active alcohols separated by liquid chromatography. J Agric Food Chem 42 320-326, 1994. 

WA Behrens, R Madere. Quantitative analysis of ascorbic acid and isoascorbic acid in foods by high-performance liquid chromatography with electrochemical detection. J Liq Chromatogr 15 753-765,... 

However, it should be mentioned that there is a flexible hand-held electrochemical instrument on the market, which can be programmed to be used in a variety of voltammetric/amperometric modes in the field [209]. Although the majority of biosensor applications described in this review were for single analyte detection, it is very likely that future directions will involve development of biosensor arrays for multi-analyte determinations. One example of this approach has been described in an earlier section, where five OPs could be monitored with an array of biosensors based on mutant forms of AChE from D. melanogaster [187]. This array has considerable potential for monitoring the quality of food, such as wheat and fruit. Developments and applications of biosensors in the area of food analysis are expected to grow as consumer demand for improved quality and safety increases. Another area where biosensor developments are likely to increase significantly is in the field of environmental analysis, particularly with respect to the defence of public... 

The analysis of trace substances in environmental science, pharmaceutical and food industries is a challenge since many of these applications demand a continuous monitoring mode. The use of immunosensors based on AuNPs in these applications should also be appropriate. Although there are many recent developments in the immunosensor field, which have potential impacts [36], nevertheless there are few papers concerning environmental analysis with electrochemical detection based on AuNPs. The application of some developed clinical immunosensors can also be extended to the environmental field. 

The literature reports many analytical techniques used for the speciation analysis of As in multifarious matrices, including food. The usual methods are GC or LC coupled with spectroscopic or electrochemical detection [185, 248] the standard detectors are AAS, ICP AES and ICP MS [192, 246, 249]. One of the more favoured techniques for the speciation analysis of As is HG AAS coupled with... 

Microbiological or immunochemical detection systems offer the advantage to screen, rapidly and at low cost, a large number of food samples for potential residues, but cannot provide definitive information on the identity of violative residues found in suspected samples. For samples found positive by the screening assays, residues can be tentatively identified and quantified by means of the combined force of an efficient liquid chromatographic (LC) separation and a selective physicochemical detection system such as UV, fluorescence, or electrochemical detection. The potential of pre- or postcolumn derivatiza-tion can further enhance the selectivity and sensitivity of the analysis. Nevertheless, unequivocal identification by these methods is not possible unless a more efficient detection system is applied. 

The system developed in this work establish a general electrochemical detection methodology that can be applied to a variety of immunosystems and DNA detection systems, including lab-on-a-chip technology, with special interest for further applications in clinical analysis, food quality and safety as well as other industrial applications. 

EcDs are used for quantitation of compounds which can be easily oxidized or reduced by an applied potential. The standard reduction potential at the electrode is measured and transformed into a detector signal. The number of compounds which can be electrochemically detected is, however, considerably smaller than the number of optically detectable compounds by UV, RI, and FL. To become oxidized or reduced, a compound must possess electrochemically active groups. EcDs are mainly used in clinical, food, and environmental analysis. 

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