Simultaneous Liquid Chromatographic Determination of Water-Soluble Vitamins, Caffeine, and Preservative in Oral Liquid Tonics

Abstract

A rapid, simple, and reliable liquid chromatographic method has been developed for the simultaneous determination of nicotinamide (niacinamide), thiamine, riboflavin, riboflavin sodium phosphate, pyridoxine, caffeine, and sodium benzoate in commercial oral liquid tonics. The 7 components are separated on a reverse phase C18 column using a mobile phase of acetonitrile-O.OlM potassium dihydrogen phosphate-triethylamine (8 + 91.5 + 0.5 v/v/v) containing 5mM sodium octanesulfonate and adjusted to pH 2.8 with phosphoric acid. Components are detected at 254 nm with attenuation 0.02 AUFS. Acetanilide is used as an internal standard. In addition to the 7 components mentioned, nicotinic acid (niacin), cyanocobalamin, and folic acid are also separated under the same conditions. Sample preparation involves only addition to internal standard solution and dilution with mobile phase and then filtration. Recoveries of the 7 components and cyanocobalamin from spiked preparations ranged from 97 to 104% with coefficients of variation of 0.9-4.2%.

Simultaneous Determination of Eight Water-Soluble Vitamins in Supplemented Foods by Liquid Chromatography

“…Acetonitrile was also assayed without good results. The pH was an extremely critical factor for the separations of vitamins, as has been previously reported ( , ). pH values from 2.5 to 4.0 were tested by the addition of orthophosphoric acid to the mobile phase, and it was concluded that the pH should be lower than 3.0 to resolve the critical vitamin pairs niacin/pyridoxine and riboflavin/cyanocobalamin.…”

Acerola nectar with added microencapsulated probiotic

“…The ascorbic acid content was determined by HPLC with a mobile phase of acetonitrile plus deionized water in the proportion of 3:1, filtered and degassed according to the methodology of Maeda, Yamamoto, Owada, Sato, and Masui (1989). The chromatographic conditions used were the following: Shimadzu model class 10 chromatograph; model SPD-M6A diode array detector with a wavelength of 245 nm; mobile phase of KH 2 PO 4 (Synth), heptanesulfonic acid, sodium salt (Acros), triethylamine (Acros) and methanol (Tedia), with a flow rate of 0.8 mL min À1 .…”

Furan Levels in Coffee As Influenced by Species, Roast Degree, and Brewing Procedures

“…Determination of Ascorbic Acid. Ascorbic acid was determined by liquid chromatography with diode array detector (HPLC-DAD) according to Maeda et al 17 Ascorbic acid was extracted from ground green coffee (5 g) with 50 mL of acidic water (pH 3) during 15 min under agitation. Following filtration, the extract was injected into a Shimadzu SPD-M6A HPLC-DAD system (Shimadzu Corp., Tokyo, Japan) equipped with a Rheodyne 7725i sample injector (Rheodyne) with a 200 μL sample loop.…”