Development of a robotic-HPLC determination of riboflavin vitamers in food

Russell, L. F.; Brooks, L.; McRae, K.B.

doi:10.1016/s0308-8146(97)00216-1

Cited by 18 publications

(9 citation statements)

References 8 publications

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“…Flavins have primarily been detected in biofilm research via high–performance liquid chromatography (HPLC) [25, 29, 36–40], liquid chromatography–mass spectrometry (LC–MS) [26], cyclic voltammetry (CV) [26, 41, 42], or differential voltammetry [43]. Other methods used to detect flavins include polarography [44, 45], flow injection analysis with fluorescence [46], square–wave voltammetry (SWV) using a mercury drop electrode [47], and spectrofluorimetry [48, 49].…”

Section: Introductionmentioning

confidence: 99%

A voltammetric flavin microelectrode for use in biofilms

Nguyen

Renslow

Babauta

et al. 2012

Sensors and Actuators B: Chemical

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Biofilms used in bioelectrochemical systems are expected to transfer electrons using electron transfer mediators. One mediator type, flavins, which includes flavin mononucleotide, riboflavin, and flavin adenine dinucleotide, has been found to be endogenously produced by Shewanella oneidensis MR-1. However, the presence and concentration of flavins inside a S. oneidensis MR-1 biofilm have never been reported. The goal of this study was to develop a flavin microelectrode capable of measuring flavins inside a living biofilm and apply it to a biofilm which produces flavins. Because flavins are electrochemically active molecules, the flavin microelectrode was based on detection via square-wave voltammetry. The microelectrode consisted of a carbon working electrode with a 10–30 μm tip diameter, a built-in platinum counter electrode, and a Ag/AgCl reference electrode, all enclosed in a glass outer case. The microelectrode was calibrated between 0.1 μM and 10 μM flavins and showed a linear correlation between flavin concentration and peak currents located at −424 mVAg/AgCl on a square-wave voltammogram. We also developed a model to explain the electrochemical mechanism of flavin detection, and to determine the effective surface area of the microelectrode, the standard reduction potential, and the transfer coefficient. We found that the effective surface area of the microelectrode was close to 100 times the projected surface area. The model predicted a standard reduction potential for RF/RFH2 of −419 mVAg/AgCl at 20 °C and a transfer coefficient of 0.45. Lastly, we measured flavin concentration inside a S. oneidensis MR-1 biofilm grown on a glass surface using oxygen as the electron acceptor. The flavin concentration reached 0.7 μM, increasing near the bottom of the biofilm, where no oxygen was present. This shows the possibility that flavins are produced in the anaerobic zone to act as intermediate electron acceptors in the deeper parts of the biofilm, where there is no oxygen.

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Section: Introductionmentioning

confidence: 99%

A voltammetric flavin microelectrode for use in biofilms

Nguyen

Renslow

Babauta

et al. 2012

Sensors and Actuators B: Chemical

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“…There is growing interest in knowing not only total RF content but also flavin composition of food. Liquid chromatography (LC) using reversed phase columns has been applied to the determination of total RF (6)(7)(8)(9)(10)(11)(12) and also to the separation of the main flavins in foods, RF, FMN, and FAD (4,(13)(14)(15)(16)(17)(18)(19)(20)(21)(22). RF has a strong inherent fluorescence and can be detected very specifically with high sensitivity at its maximum fluorescence intensity at pH 6-7.…”

Section: Introductionmentioning

confidence: 99%

Liquid Chromatographic Analysis of Riboflavin Vitamers in Foods Using Fluorescence Detection

Viñas

Balsalobre

López-Erroz

et al. 2004

J. Agric. Food Chem.

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The analysis of free riboflavin (RF) and its two coenzymes, flavin mononucleotide (FMN) and flavin-adenine dinucleotide (FAD), is optimized using reversed phase liquid chromatography with fluorescence detection. The stationary phase was amide-based and endcapped with trimethylsilyl, and the isocratic mobile phase consisted of a 10:90 v/v acetonitrile/phosphate buffer (pH 5). Peaks were identified by the retention characteristics and fluorescence spectra. Detection limits were 0.03, 0.05, and 0.24 ng for RF, FMN, and FAD, respectively. The vitamins were extracted using acetonitrile and the phosphate buffer. The procedure was applied to the determination of B2 vitamers in different types of food such as milk and soy-based infant formulas, beer, fruit juices, and honey of different types. Most B2 vitamin appeared as RF, while the coenzymes were present in lower amounts. The method was validated using two certified reference materials, and results within the certified range were obtained.

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“…However, as we were unable to obtain either of these products we used lumiflavin, a known riboflavin analogue, which was readily available. Several papers have discussed the possibility that lumiflavin is a photodegradation product of riboflavin [16,19], so we assessed this using our method. Aliquots of the same plasma sample were spiked with FAD, FMN, riboflavin, and lumiflavin and exposed to full range UV light for varying lengths of time (15 -60 minutes).…”

Section: Reference Population Comparison With Tpn Patientsmentioning

confidence: 99%

“…Assessment has been made on the basis of clinical signs, urinary excretion, plasma and erythrocyte content, and erythrocyte glutathione reductase activity (EGRAC) [12]. Clinical signs are difficult to evaluate as severity can vary widely between individuals [13], so the question remains as to which method is most suitable for routine flavin analysis [3,[14][15][16]. Direct HPLC analysis is more sensitive and specific than other methods.…”

Section: Introductionmentioning

confidence: 99%

Comparison of a Direct and Indirect Method for Measuring Flavins-Assessing Flavin Status in Patients Receiving Total Parenteral Nutrition

Hamilton

Woodside²,

McIlveen³

et al. 2009

TOCCHEMJ

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Background: Riboflavin, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) are cofactors in oxidation-reduction reactions. The aim of this study was to compare a direct high performance liquid chromatography (HPLC) method with an indirect enzymatic method to assess flavin status and establish reference intervals. The HPLC method was used to assess prevalence of flavin deficiency in total parenteral nutrition (TPN) patients. Method: Blood was obtained from 90 healthy volunteers and 51 TPN patients. Results for each method were compared using Spearmans Rank correlation. Results from reference groups and TPN patients were compared using Mann-Whitney U tests. Results: Erythrocyte glutathione reductase activity coefficients (EGRAC) correlated with flavin levels measured by HPLC (p<0.001). HPLC was chosen for TPN samples analyses due to superior sensitivity. There was no significant difference between FAD and FMN levels in controls and TPN patients, although TPN patients had significantly higher levels of riboflavin than controls (p<0.001). Conclusion: HPLC is superior to the EGRAC assay for assessing flavin status. Hyporiboflavinosis is not prevalent in TPN patients.

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Development of a robotic-HPLC determination of riboflavin vitamers in food

Cited by 18 publications

References 8 publications

A voltammetric flavin microelectrode for use in biofilms

A voltammetric flavin microelectrode for use in biofilms

Liquid Chromatographic Analysis of Riboflavin Vitamers in Foods Using Fluorescence Detection

Comparison of a Direct and Indirect Method for Measuring Flavins-Assessing Flavin Status in Patients Receiving Total Parenteral Nutrition

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