HPLC Separation of Carboxylic Acids
HPLC separation of carboxylic acids (nicotinic acid, benzoic acid and acetylbenzoic acid) on Primesep B2 column using an isocratic method by reverse-phase and anion-exchange mechanisms. The elution of carboxylic acids using the same isocratic method and mobile phase can be reversed by using a reverse-phase cation-exchange mechanisms of the Primesep 100 column. The mobile phase is water, acetonitrile (MeCN, ACN) and formic acid with a UV detector.
Acetylbenzoic AcidBenzoic AcidNicotinic Acid
HPLC Separation of Pyridinecarboxylic Acids
Pyridinecarboxylic acids exist as three isomers with different position of carboxylic acid relative to nitrogen in pyridine. Three isomers of pyridinecarboxylic acid (picolinic or 2-pyridinecarvoxylic acid, niacin or 3-pyridinecarboxylic acid, isonicotinic or 4-pyridinecarboxylic acid), along with pyridinedicarboxylic acid, are separated on a Primesep 100 column. Pyridinecarboxylic acids have a similar empirical formula, and are very similar in terms of hydrophobicity and ionic properties. Small differences in these properties are enough to achieve good separation on cation-exchange mixed-mode HPLC column like Primesep 100. Retention time for all compounds is controlled by the amount of acetonitrile and amount of ions in the mobile phase. Ions in the mobile phase can be created by organic and inorganic acids and corresponding salt buffers. Various detection techniques can be used for monitoring pyridinecarboxylic acids. Other ionizable isomers can be successfully separated on mixed-mode columns.
Isonicotinic AcidNicotinic AcidOrganic AcidsPicolinic AcidPyridinedicarboxylic Acid
HPLC Separation of Vitamin C, Vitamin Group B, and Related Impurities
Vitamin C (ascorbic acid) and Vitamins Group B are separated on Obelisc N mixed-mode column. Method can be used in quantitation and determination of polar vitamins in various formulations and dietary supplements. HPLC method can be based on UV, Evaporative Light Scattering Detection (ESLD), RI or MS detection. Effect of sample matrix can be eliminated by changing mobile phase conditions. Buffer concentration, buffer pH and amount of ACN will affect every vitamin differently due to difference in polar and ionic properties.
3-Aminopyridine4-Aminopyridine/FampridineAscorbic AcidBarbituric AcidIsonicotinic AcidNicotinic AcidPyridoxineVitamin B2 (Riboflavin)Vitamin B6 (Pyridoxine)
HILIC Separation of Vitamins Group B
Separation of vitamins group B is achieved on Obelisc N column in HILIC mixed-mode. Vitamins of this group are different in polarity and ionic properties. Retention and separation is achieved by optimization of amount of ACN, buffer and buffer pH. Combination of UV and ELSD detection is used to monitor HPLC separation. B vitamins are water-soluble vitamins that play an important role in cell metabolism. Supplements containing all six are generally referred to as a vitamin B complex. Individual B vitamin supplements are referred to by the specific name of each vitamin. This method can be used to analyze individual B vitamins as well as vitamin B complex. Isolation of impurities as well as degradation products is possible by preparative chromatography.
Nicotinic AcidVitamin B1 (Thiamine)Vitamin B2 (Riboflavin)Vitamin B3 (Niacin)Vitamin B5 (Pantothenic Acid)Vitamin B6 (Pyridoxine)
Analysis of Nicotinic Acid in Nicotinamide
Nicotinamide is the amide form of nicotinic acid. Nicotinic acid is in the vitamin B group and is converted to nicotinamide in vivo. Primesep 100 was used to separate nicotinamide and nicotinic acid. Concentrations of nicotinic acid as low as 0.1ppm could be used.Primesep 100 separates acids using ion-exclusion, retains basic compounds by cation-exchange, and neutral compounds by reverse-phase mechanism.
||Primesep 100, 4.6x150 mm, 5 µm, 100A
||MeCN/H2O - 5/95%
||Na2HPO4 pH 3.0- 10 mM
||UV, 230 nm
|Class of Compounds
|| Acid, Hydrophilic, Ionizable, Vitamin, Supplements
||Nicotinic Acid, Nicotinamide
HPLC Separation Of Mixture of Pyridylacetic Acids And Their Derivatives
2-Pyridylacetic acid hydrochloride3-Acetylpyridine3-Pyridylacetic acid hydrochloride4-Pyridylacetic acid hydrochlorideNicotinic AcidPyridyl-3-thioacetomorpholide