Determination Of Nicotinic Acid Research Articles

Potentiometric Sensors Based on MF-4SC Membranes and Carbon Nanotubes for the Determination of Nicotinic Acid in Aqueous Solutions and Pharmaceuticals

Perfluorosulfonic acid membranes MF-4SC with a uniform and gradient distribution of multi-walled carbon nanotubes (CNTs) along the length of the samples have been synthesized. The effect of the presence and concentration of CNTs in the membranes on the equilibrium and transport properties of materials has been studied. The cross sensitivity of Donnan potential (DP) sensors to nicotinic acid, sodium, and hydroxonium ions for membranes of different compositions has been determined. The incorporation of 0.5–1.0 wt. % CNTs into a membrane has led to a decrease in the detection limits of nicotinic acid ions in aqueous solutions by a factor of 2–3. An array of cross-sensitive DP-sensor based on MF-4SK and MF-4SC + 1.0 wt. % CNT membranes has been used to determine the active and auxiliary substances in a pharmaceutical based on nicotinic acid. The relative error of determination is 1.9%.

Determination of Nicotinic Acid and Nicotinamide Forms of Vitamin B3 (Niacin) in Fruits and Vegetables by HPLC Using Postcolumn Derivatization System

Determination of Nicotinic Acid and Nicotinamide Forms of Vitamin B3 (Niacin) in Fruits and Vegetables by HPLC Using Postcolumn Derivatization System

Determination of Nicotinic Acid and Metabolites in Urine, Cosmetics, and Pharmaceuticals by High-Performance Liquid Chromatography with Novel Electrochemical Detection

ABSTRACTSilver and gold electrodes were used with high-performance liquid chromatography and an electrochemical detector to determine nicotinic acid and its metabolites (1-methylnicotinamide chloride, nicotinic acid hydroxamate, nicotinamide, nicotinic acid, and methyl nicotinate). Nicotinic acid derivatives were more efficiently oxidized on a gold electrode than on a silver electrode. In direct current mode, with the current at a constant potential and with suitable experimental parameters, linear dynamic range for these derivatives was from 0.4 to 8.0 mg L−1. The limits of quantification were less than 1.0 ng. The developed method was used to determine nicotinic acid and its derivatives in human urine, cosmetics, and pharmaceuticals. The results for high-performance liquid chromatography with electrochemical and ultraviolet detection were comparable.

Potentiometric cross-sensitive PD sensors for the simultaneous determination of nicotinic acid and pyridoxine hydrochloride in aqueous solutions

A potentiometric multisensory system is developed for the rapid simultaneous determination of pyridoxine hydrochloride and nicotinic acid in aqueous solutions. Sensors for which analytical signal is constructed by the Donnan potential are used within a multisensory system as cross-sensitive elements. In solutions containing both components in concentrations from 1.0 × 10−4 to 1.0 × 10−2 M, the relative error of analysis did not exceed 10%. Standard titrimetry and spectrophotometry methods were used for the reference analysis of the target vitamins in multicomponent solutions.

Voltammetric determination of nicotinic acid by glassy-carbon electrode modified with multiwall carbon nanotubes

A glassy-carbon electrode modified with a thin film of multiwall carbon nanotubes is used for the determination of nicotinic acid (NA). At the electrode, the latter yields a well-defined and very sensitive oxidation peak at 0.21 V (SCE). Investigation of the electrochemical behavior of NA shows that the electrode significantly enhances the NA oxidation peak current, compared with the non-modified electrode. Based on this, a very sensitive and simple electrochemical method is proposed for the NA determination after the optimization of all experimental parameters. The oxidation peak current is proportional to the NA concentration over the range 2×10−7 to 4×10−5 M, and the detection limit is 8×10−8 M after a 4-min accumulation. The relative standard deviation of 5.4% for the successive determination of 1×10−6 MNA (n=10) indicates excellent reproducibility. The analysis method is successfully demonstrated using tablet samples.

The determination of nicotinic acid in plasma by mixed-mode liquid chromatography–tandem mass spectrometry following ion exchange solid phase extraction

An assay for nicotinic acid in plasma samples has been developed using ion exchange solid phase extraction in 96-well format followed by mixed-mode ion exchange/reversed-phase liquid chromatography with positive ion tandem mass spectrometry detection. The assay avoids the need for time-consuming derivatisation procedures or involatile ion-pair chromatography reagents. The assay is linear over the wide range 0.05-20 microg/mL, based on a 100 microL sample (correlation coefficient>0.99). The assay is accurate and precise (bias and coefficient of variation<18%) over this calibration range.

Enzymatic extraction procedure for the liquid chromatographic determination of niacin in foodstuffs

An enzymatic extraction procedure for the determination of the niacin present in foodstuffs by means of a NAD glycohydrolase (or NADase) has been proposed as a replacement for the hydrochloric acid hydrolysis usually used. The determination of nicotinic acid and nicotinamide by HPLC/fluorimetry [according to Lahély et al. (Food Chemistry, 1999, 65, 129)] has made it possible to show that the acid treatment very definitely led to the release of forms of nicotinic acid not bioavailable in some foodstuffs (wheat flour, wheat germ, peanuts), unlike hydrolysis with NADase from Neurospora crassa [37 °C, 18 h, pH 4.5, 24 μg g−1 of sample (0.013 U g−1)] which led to both an accurate determination of the respective contents of nicotinic acid and nicotinamide and a reliable estimation of the bioavailable niacin in the different foodstuffs analysed. The combined addition of a protease and an amylase to the NADase, sometimes recommended when acid hydrolysis was used, proved to be superfluous.

Enzymic method for the amperometric determination of nicotinic acid in meat products.

An enzymic method for the determination of nicotinic acid is described, based on the indirect electrochemical monitoring of nicotinic acid via its reaction with oxygen in the presence of nicotinic acid hydroxylase. Derivative amperometric signals due to oxygen depletion enable a one-point kinetic analysis to be carried out. Nicotinic acid hydroxylase catalyses the hydroxylation of nicotinic acid to produce 6-hydroxynicotinic acid, which is accompanied by a stoichiometric consumption of oxygen. The method was applied successfully to the analysis of real samples.

Determination of Water Soluble Vitamins By Liquid Chromatography with Ordinary and Narrow-Bore Columns

Abstract A reversed phase high performance liquid chromatographic method is described for the simultaneous determination of nicotinic acid, nicotinamide, pyridoxine, thiamine, folic acid and riboflavin. The vitamins were separated on a C8 bonded phase column and eluted with a dihidrogen phosfate buffer, hexanesulphonate and methanol as the eluent. A rapid spectral detector Diode Array was used to optimise the detection of each vitamin. All vitamins were separated in less than 12 minutes. This method was applied to the determination all the vitamins in multivitamin Pharmaceuticals. Recovery studies showed good results for all solutes (93.4%–106.5%) and some day coefficients of variation ranging from 0.91% to 4.95%. Narrow bore columns were recommended because this alternative provided a good separation efficiency, plus greater economy and sensibility. Finally, the performance of an ordinary UV detector and that of a rapid spectral detector in this type of determination were critically compared.

An Improved Method for the Determination of Nicotinic Acid in Human Plasma by High-Performance Liquid Chromatography

Abstract A simple, specific, and sensitive HPLC method was developed for the determination of nicotinic acid in human plasma. Plasma is deproteinized with acetonitrile and centrifuged. The supernatant solution is evaporated and reconstituted in mobile phase. Separation is achieved using an IB-SIL CN column with a mobile phase composed of acetonitrile:methanol:water:acetic acid (700:150:150:1, v/v/v/v). Detection is by ultraviolet absorbance at 263 nm. The retention times of nicotinic acid and 6-methyl nicotinic acid (internal standard) are approximately 3.8 and 8.8 minutes, respectively. The assay is linear in concentration ranges of 100 to 10,000 ng/ml (original method) and 20 to 2,000 ng/mL (high-sensitivity method). The analysis of pooled quality controls (150, 1,250, and 7,530 ng/mL) demonstrates excellent precision with relative standard deviations (RSD) (n = 18) of 3.4%, 2.7%, and 2.8%, respectively. For the high sensitivity method, quality control pools prepared at 60, 150, and 1,250 ng/mL had RSDs...

Isotachophoretic analysis of pharmaceutic formulations with different matrices: Determination of nicotinic acid in capsules, tablets, dragees, ointments and tinctures

The selectivity of isotachophoresis is investigated concerning the quantitative determination of an anionic agent in a variety of pharmaceutic application forms with different matrices. As a result, no interferences caused by matrix components were observed in any case. Therefore sample pretreatment can be neglected. The simultaneous quantitation of other anionic constituents, present in the formulations, is possible. The method is evaluated by other analytical characteristics besides selectivity, like precision, accuracy and time of analysis. The contributions of aliquotation and isotachophoretic measurement to the total error were determined by analysis of variance. Systematic errors, due to adsorption of the analyte on solid matrix material were examined by standard addition. The results of the analytical characteristics indicate the excellent applicability of isotachophoresis for the routine analysis of anionic analytes in pharmaceutic preparations

The determination of nicotinic acid by fluorimetric densitometry.

A method is reported for the rapid determination of added nicotinic acid in meat. Nicotinic acid is converted on silica plates into a fluorescent compound by ultraviolet irradiation. After chromatographic separation from nicotinamide, the concentration is measured by means of a densitometer.

Determination of nicotinic acid and its derivatives in industrial preparations

Determination of nicotinic acid and its derivatives in industrial preparations

The determination of nicotinic acid and nicotinamide by thin-layer chromatography and in situ fluorimetry

Abstract The specific determination of traces of nicotinamide and nicotinic acid by a combination of thin-layer chromatography and direct fluorescence spectroscopy is described. Two instruments are compared for performance. Instrumental detection limits of 0.001–0.002 ;μg/spot are reported. For an artificial mixture an average error of about 8% was found. The relative standard deviation for biological samples was between 8 and 14%. The method can be used for routine analysis and compares favourably with reflectance spectroscopic and fluorescence quenching techniques. The total time of analysis is 5–6 h with an actual working time of 2 h.

Determination of nicotinic acid in technical solutions

Determination of nicotinic acid in technical solutions

A modified cyanogen bromide method for the determination of nicotinic acid in vegetable foodstuffs.

The cyanogen bromide-aniline hydro chloride system for the determination of nicotinic acid in foodstuffs has been systematically studied, and a simplified and rapid procedure for the estimation of the vitamin has been developed.

Determination of Nicotinic Acid in Coffee by Paper Chromatography.

Determination of Nicotinic Acid in Coffee by Paper Chromatography.

Determination of Nicotinic Acid and Sodium Nicotinate

Determination of Nicotinic Acid and Sodium Nicotinate

THE CHEMICAL DETERMINATION OF NICOTINIC ACID IN PLANT MATERIALS

THE CHEMICAL DETERMINATION OF NICOTINIC ACID IN PLANT MATERIALS

Determination of nicotinic acid in human blood (I)

AbstractAfter improving the König BrCN‐reaction and applying it to human blood the following results were obtained. When haemolyzed blood is deproteinized by means of metaphosphoric acid, no cozymase is precipitated, but all of the pyridine compounds remain in the aqueous solution.Probably nicotinamide is then present, but as the amount of nicotinic acid found after hydrolysis is much larger, there must be some other pyridine compound present in blood, which also yields nicotinic acid after hydrolysis.There is strong evidence that the pyridine compound determined after hydrolysis is indeed nicotinic acid.A routine method for the estimation of nicotinic acid in blood is described.