Benzoic acid

Effect of Acid in Mobile Phase on Retention of Neutral, Acidic, Basic and Zwitterionic Compounds on Core-Shell Mixed-Mode Column
Application description

Seven compounds with different properties were used to study an effect of different acids in the mobile phase on retention of neutral, acidic, basic and zwitterionic compounds on core-shell mixed-mode Coresep 100 column. Retention of neutral compounds (propylparaben and benzoic acid to some extent) are not affected by change of the acid. Basic compounds (norphenylephrine, pyridine, 2-aminopyridine) respond the most to change of the strength of acidic additive. Several folds increase in retention time was observed when sulfuric acid was replaced with formic acid in the mobile phase. Effect of acid on retention time of zwitterionic amino acids was less pronounced but still provided excellent retention and peak shape for zwitterionic compounds (5-aminosalicylic acid, phenylalanine). This methods and Coresep 100 column can be used to retain and separate other acidic, basic, neutral and zwitterionic compounds without the use of ion-pairing reagent in the mobile phase. Various detection techniques can be used based on the properties of the mobile phase and analytes. Methods are compatible with mall major detection techniques 9UV, ELSD, CAD, RI, MS). Core-shell mixed-mode columns provide great combination of unique selectivity, speed and efficiency.

Conditions of Experiment
Column: Coresep 100
Separation Modes:
Column Dimenstions: 4.6 x 150 mm, 2.7 um, 90A
Mobile Phase:
Detection: UV 255 nm
Sample:
Injection:
Flow rate: 1 mL/min
Analytes
Class of compounds: Amines, Amino acid, Aromatic acid, Aromatic base, Aromatic compound, Catecholamine, Drug, Isomer, Neurotransmitter, Organic acid, Preservative, Pyridine, Supplement
Nature of compounds: Acidic, Basic, Hydrophilic, Hydrophobic, Neutral, Polar, Zwitterionic
Compounds: 5-Aminosalicylic acid, Norphenylephrine, Phenylalanine, Pyridine, Benzoic acid, 2-Aminopyridine, Propylparaben
HPLC Analysis of Drug Composition on Heritage C18 Column According to US Pharmacopeia
Conditions of Experiment
Column: Heritage С18
Separation Modes: reversed-phase
Column Dimenstions: 4.6 x 100 mm, 5 um, 100A
Mobile Phase: MeOH/H2O/AcOH 30/67/3
Detection: UV 275 nm
Sample: 0.2 mg/ml
Injection: 5 uL
Flow rate: 1 mL/min
Analytes
Class of compounds: Aromatic acid, Aromatic compound, Drug, Organic acid, Stimulant, Xanthine
Nature of compounds: Acidic, Hydrophilic, Hydrophobic, Neutral, Polar
Compounds: Acetaminophen, Caffeine, Aspirin, Benzoic acid, Salicylic acid
HPLC Analysis of Drug Guaifenesin on Heritage C18 Column According to US Pharmacopeia
Conditions of Experiment
Column: Heritage С18
Separation Modes: reversed-phase
Column Dimenstions: 4.6 x 150 mm, 5 um, 100A
Mobile Phase: MeOH/H2O/AcOH 40/60/1
Detection: UV 254 nm
Sample: 0.3 mg/ml
Injection: 5 uL
Flow rate: 1 mL/min
Analytes
Class of compounds: Aromatic acid, Aromatic compound, Drug, Organic acid
Nature of compounds: Acidic, Hydrophilic, Neutral, Polar
Compounds: Guaifenesin, Benzoic acid
Selectivity Difference for Polar Compounds in Reversed-Phase and Mixed-Mode Separation on Coresep 100 HPLC Column
Application description

Core-shell mixed-mode columns offer unique selectivity which comes from the presence of two mechanisms - reversed-phase and ion-exchange. The alternative selectivity of mixed-mode columns can be used when order of elution or resolution between compounds needs improvement. Even for neutral compounds a different selectivity can be obtained. A method for common components of headache medications (acetaminophen, caffeine, and benzoate) was developed on our Coresep 100 column. Efficiency and peak shape are comparable to leading brand core-shell reversed-phase columns.

Conditions of Experiment
Column: Coresep 100
Separation Modes: reversed-phase
Column Dimenstions: 3.2 x 50 mm, 2.7 um, 90A
Mobile Phase: 20% ACN with 0.1% TFA
Detection: UV 250 nm, ELSD
Sample: 0.3 mg/ml
Injection: 1 uL
Flow rate: 1 ml/min
Analytes
Class of compounds: Aromatic acid, Aromatic compound, Drug, Organic acid, Stimulant, Xanthine
Nature of compounds: Acidic, Hydrophilic, Neutral
Compounds: Acetaminophen, Caffeine, Benzoic acid
HPLC Analysis of Hydrophilic Acids on Coresep SB Column in Reversed-Phase and Anion-Exchange Modes
Application description

Mixture of hydrophilic acidic compounds are separated in reversed-phase anion-exchange mode on core-shell mixed-mode column. Method is robust, reliable and fast and can be used for analysis of underivatized acids without ion-pairing reagent.

Conditions of Experiment
Column: Coresep SB
Separation Modes: reversed-phase and anion-exchange
Column Dimenstions: 3.2 x 100 mm, 2.7 um, 90A
Mobile Phase: 50% ACN with 50 mM sodium phosphate (monobasic) pH 3
Detection: UV 230 nm
Sample: 0.3 mg/ml
Injection: 3 uL
Flow rate: 0.5 mg/ml
Analytes
Class of compounds: Aromatic acid, Organic acid
Nature of compounds: Acidic, Hydrophilic, Polar
Compounds: Benzoic acid, Maleic acid, Fumaric acid