4-Hydroxybenzoic acid

HPLC Analysis of Aromatic Carboxylic Acids on Amaze TR Mixed-Mode Column
Application description

Aromatic organic acids are used as building blocks in chemistry, additives in various formulations and counter-ions in drug production. In most of the cases, these acids are hydrophilic and acidic in nature with limited retention in reversed-phase chromatography. We have developed a simple, robust and isocratic method to separate mandelic, gallic, phthalic and 4-hydroxybenzoic acids on the Amaze TR HPLC column. All four acids are retained and separated by combination of weak reversed-phase and weak anion-exchange mechanisms. The baseline separation is achieved within 5 minutes. This method can be used for the analysis of hydrophilic and hydrophobic organic and inorganic acids with LC/MS-compatible conditions.

Conditions of Experiment
Column: Amaze TR
Separation Modes: reversed-phase, anion-exchange
Column Dimenstions: 4.6x50 mm, 3 um, 100A
Mobile Phase: 20% ACN with 20 mM AmFm pH 3
Detection: UV 255 nm
Sample: 0.3 mg/ml
Injection: 3 ul
Flow rate: 1 ml/min
Analytes
Class of compounds: Aromatic acid, Isomer, Organic acid, Preservative
Nature of compounds: Acidic, Hydrophilic, Hydrophobic, Polar
Compounds: Mandelic acid, Gallic acid, Phthalic acid, 4-Hydroxybenzoic acid
HPLC Analysis of Six Organic Acids on Heritage MA Mixed-Mode Column
Conditions of Experiment
Column: Heritage MA
Separation Modes: reveresed-phase, anion-exchange
Column Dimenstions: 4.6 x 150 mm, 5 um, 100A
Mobile Phase: 35% ACN with 50 mM AmFm pH 3
Detection: UV 255 nm
Sample: 0.2 mg/ml
Injection: 5 uL
Flow rate: 1 ml/min
Analytes
Class of compounds: Aromatic acid, Organic acid, Preservative
Nature of compounds: Acidic, Hydrophilic, Hydrophobic, Polar
Compounds: Gallic acid, 4-Hydroxybenzoic acid, Caffeic acid, Mandelic acid, Maleic acid, Atrolactic acid