Simultaneous Determination Of Riboflavin Research Articles

Electrochemical sensor based on molecularly imprinted copolymer for selective and simultaneous determination of riboflavin, dopamine, and L-tryptophan.

This research shows the exact detection of riboflavin (RF), dopamine (DA), and L-tryptophan (Trp) through molecularly imprinted polymer (MIP) based on the electropolymerization method. MIP was placed on the surface of the glassy carbon electrode (GCE) by electropolymerization of monomers such as catechol and para-aminophenol, in the presence of all three analytes. The introduced sensor was investigated using field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), Fourier-transform infrared spectroscopy (FTIR), and electrochemical methods, for example, electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and differential pulse voltammetry (DPV). The MIP/GCE performs well in terms of selectivity, reproducibility, repeatability, and stability. This sensor revealed good linear ranges of 0.005-500 μM for RF, 0.05-500 μM for DA, and 0.1-250 μM for Trp with limits of detection (LOD) as 0.0016 μM, 0.016 μM, and 0.03 μM for RF, DA, and Trp, respectively. The modified GCE was successfully applied to detect RF, DA, and Trp in serum and milk samples with satisfactory results.

Simultaneous determination of riboflavin and chloramphenicol by MoS2 nanosheets decorated three-dimensional porous carbon: Reaction mechanism insights by computational simulation

Passive inhalation of chloramphenicol (CAP) and untimely intake of riboflavin (RF) can cause damage to physical function. The quantitative detection of these two substances is conducive to monitoring human health, while a method for detecting these two substances at the same time has not been reported. In this paper, an efficient sensor for simultaneous detection of RF and CAP by culturing molybdenum disulfide nanosheets on nitrogen-doped seaweed-derived porous carbon ([email protected]2) has been prepared. The introduction of N-PC improved the conductivity of the composite and reduced the agglomeration of the MoS2 nanosheets to guarantee the exposure of more catalytic sites. Consequently, the composite material represented improved electrochemical performance and the ideal simultaneous detection of CAP and RF was achieved in the linear range of 10 ~ 500 μM. In addition, the sensor has been proven to have sufficient stability and anti-interference, which makes it potential in practical applications. This work also noticed the reaction sites and activities of RF and CAP prediction through orbit-weighted dual descriptor, providing a direction for an in-depth understanding of the reaction mechanism of target molecules at the electrode interface.

Simultaneous determination of riboflavin and pyridoxine by UHPLC/LC–MS in UK commercial infant meal food products

An assay for the simultaneous quantitative determination of riboflavin and pyridoxine in eight different complementary infant meal products has been developed in order to (1) estimate the daily intake of these vitamins from commercial infant food consumption, and (2) ascertain their nutritional suitability relative to dietary guidelines for the 6–9months age group. The method involves mild hydrolysis of the foods, an extraction of the supernatant by centrifugation followed by quantitative determination using ultra-high performance liquid chromatography. Separation of the two water soluble vitamins is achieved within one minute and the resultant sample is also LC–MS compatible. Despite wide individual differences between brands (p=6.5e-12), no significant differences were observed in the level of pyridoxine between the meat and vegetable-based varieties (p=0.7) per 100g of commercial infant food. Riboflavin was not detected in any of the samples where the detection limit was below 0.07μg/mL. In terms of the Reference Nutrient Intake (RNI) of pyridoxine for 6–9months old infants, the complementary infant meal products analysed herein provided less than 15% of the RNI values with mean (SD) values of 12.87 (±4.46)% and 13.88 (±4.97)% for the meat- and vegetable-based recipes, respectively. The estimated total daily intake of riboflavin and pyridoxine from the consumption of commercial complementary food was found to be satisfactory and in accordance with the Dietary Reference Values (DRVs). The intake of both riboflavin and pyridoxine was estimated to be mainly derived from the consumption of formula milk which could be a cause of concern if the quality of an infant’s milk diet is compromised by an inadequate or lack of supplemented milk intake. The results of this study suggest that the selected commercial complementary infant foods in the UK market may not contain the minimum levels of riboflavin and pyridoxine required for the labelling declaration of the micronutrient content of such products as recommended by Commission Directive 2006/125/EC.

GROWTH RESPONSE OF LACTOBACILLUS RHAMNOSUS TO MICROAEROPHILIC INCUBATION AND ADDITION OF REDUCTANTS IN A RIBOFLAVIN MICROTITER PLATE ASSAY

ABSTRACT Given the importance of riboflavin in human diets, a rapid riboflavin assay is needed by the food industry to allow simultaneous determination of riboflavin in numerous food sources. The growth responses of Lactobacillus rhamnosus to microaerophilic conditions and three reducing agents were examined as an attempt to reduce riboflavin assay time. Ascorbic acid, dithiothreitol and thioglycollate were applied at three concentrations. None of the concentrations of reducing agents caused a further increase of bacterial optical density (OD) or had a significant effect on the growth rates. More optimal microaerophilic conditions were achieved through the use of an anaerobic chamber. The growth rate of L. rhamnosus under microaerophilic conditions (0.30 ± 0.05/h) was not significantly different (P > 0.05) from the growth rate of the bacteria under aerobic conditions (0.34 ± 0.07/h). However, after 14 h of bacterial growth, the OD of the bacterial culture under anaerobic hood incubation (0.71 ± 0.09) was significantly higher (P < 0.05) than under aerobic incubation conditions (0.58 ± 0.05). Additional research is needed involving more controlled atmospheres for incubation during growth and a wider range of reductants to optimize and shorten the time required for riboflavin microtiter plate assay.PRACTICAL APPLICATIONSQuantifying riboflavin in foods and food ingredients is important to the food industry. Lactobacillus rhamnosus growth response to varying levels of riboflavin is used to estimate the amount of this vitamin. In an effort to optimize growth on microtiter plates and decrease assay time, microaerophilic conditions were examined. Although rate of growth was not altered, cell concentration measured as optical density (OD) did increase. Microaerophilic incubation of microtiter plates represents a potential approach to decrease assay time and provide the food industry with more timely results.

Voltammetric Behavior of Certain Vitamins and Their Determination in Surfactant Media

The behavior of riboflavin and L - ascorbic acid in surfactant media has been studied by cyclic voltammetry at a carbon paste electrode. The surfactants employed were certain ionic and a nonionic, viz., cetyltrimethyl ammonium bromide, cetylpyridinium chloride, sodiumdodecyl sulfate, and TritonX 100. The redox potentials of the vitamins were found to be different in different surfactants. The presence of cationic surfactants showed a shift in the peak potentials and peak currents of the vitamins. The presence of anionic surfactant, caused an increase in the peak currents of riboflavin without any change in peak potentials whereas no such effect was observed for ascorbic acid. The enhancement in the sensitivity of the carbon paste electrode towards riboflavin was made use of to determine the limit of detection and linear concentration range by the differential pulse voltammetric technique. Simultaneous determination of riboflavin and ascorbic acid was carried out. Multivitamin-multimineral pharmaceutical preparations analyzed gave satisfactory results.

Simultaneous determination of riboflavin, pyridoxine, nicotinamide, caffeine and taurine in energy drinks by planar chromatography-multiple detection with confirmation by electrospray ionization mass spectrometry

A new high-throughput method was developed to detect simultaneously riboflavin (Vitamin B 2), pyridoxine (Vitamin B 6), nicotinamide (Vitamin B 3), caffeine and taurine in energy drinks by multiple detection. Ten samples of energy drinks and six samples of beverages containing caffeine were prepared by degassing in an ultrasonic bath for 20 min. After chromatography, multi-wavelength scanning was performed by: (1) UV-absorbance measurement at 261 nm for nicotinamide and 275 nm for caffeine, (2) fluorescence measurement at 366/>400 and 313/>340 nm for riboflavin and pyridoxine, respectively, and (3) Vis-absorbance measurement at 525 nm for taurine, after post-chromatographic derivatization with ninhydrin reagent. Calibrations were linear or polynomial with determination coefficients r 2 > 0.999. Overall recoveries of the five compounds were between 81 and 106% at three different concentration levels. Repeatabilities (RSD, %) of all substances in matrix were determined to be between 0.8 and 1.5%. Intermediate precisions (RSD, %) ranged between 3.6 and 7.4% for riboflavin, 2.8 and 6.3% for nicotinamide, 2.5 and 4.4% for caffeine, 2.1 and 2.9% for taurine and 0.5 and 4.0% for pyridoxine at different concentration levels. Mass confirmation was performed by a single quadrupole MS in positive electrospray ionisation (ESI) scan mode for all substances except taurine (negative mode). This method offers a good alternative for routine analysis due to its simplicity and at the same time reliability.