4-Hydroxybenzoic acid

Comparison run on Amaze PFP, Amaze AR, Amaze SPF, and Heritage C20 columns.
| Column: | Amaze SPF |
| Separation Modes: | reversed-phase, pi-pi |
| Column Dimenstions: | 4.6x150 mm, 5 μm, 100A |
| Mobile Phase: | 35% ACN with 20 mM AmAc pH 4.5 |
| Detection: | UV 235 nm |
| Sample: | 1 mg/ml |
| Injection: | 3 μL |
| Flow rate: | 1 ml/min |
| Class of compounds: | Amines, Aromatic acid, Aromatic base, Aromatic compound, Organic acid, Organic compound, Preservative |
| Nature of compounds: | Acidic, Basic, Hydrophilic, Hydrophobic, Neutral, Polar |
| Compounds: | 4-Aminophenol, Mandelic acid, 4-Hydroxybenzoic acid, Phenol, Benzoic acid, Methylparaben |
Comparison run on Amaze PFP, Amaze AR, Amaze SPF, and Heritage C20 columns.
| Column: | Amaze AR |
| Separation Modes: | reversed-phase, pi-pi |
| Column Dimenstions: | 4.6x150 mm, 5 μm, 100A |
| Mobile Phase: | 28% ACN with 20 mM AmAc pH 4.5 |
| Detection: | UV 255 nm |
| Sample: | 1 mg/ml |
| Injection: | 3 μL |
| Flow rate: | 1 ml/min |
| Class of compounds: | Amino acid, Aromatic acid, Aromatic compound, Drug, Isomer, Organic acid, Preservative, Stimulant, Xanthine |
| Nature of compounds: | Acidic, Hydrophilic, Hydrophobic, Neutral, Polar, Zwitterionic |
| Compounds: | Caffeine, 4-Aminobenzoic acid, Aspirin, 4-Hydroxybenzoic acid, Sorbic acid, Benzoic acid |
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.
| 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 |
| 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 |
| 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 |
| 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 |