Effect of pH on Retention of Basic Compounds on Primesep C Columns

Method for separation of components of cough medication shows how retention for acetaminophen, phenylephrine and guaifenesin is controlled. Order of elution for compounds can be changed based on composition of the mobile phase. The method is compatible with UV, ELSD and LC/MS and can be used for quantitation of drugs in formulation. Primesep C mixed-mode HPLC column is ideal candidate for analysis of cough compositions. Basic compounds are well retained in mixed-mode chromatography without use of ion-pairing reagents. Several companies validated this approach. The method is reproducible and robust and can be used in both production environments and R&D. This HPLC method can be adopted as general approach for analysis of basic compounds in various mixtures.


Column Primesep C, 3×50 mm, 5 µm, 100A
Mobile Phase MeCN
Buffer AmAc
Flow Rate 0.5 ml/min
Detection UV, 270 nm




Class of Compounds
Drug, Analgetic, Acid, Hydrophilic, Ionizable,
Analyzing Compounds Acetaminophen, Pseudoephedrine, Guaifenesin

Application Column

Primesep C

The Primesep family of mixed-mode columns offers a wide variety of stationary phases, boasting unprecedented selectivity in the separation of a broad array of chemical compounds across multiple applications. Corresponding Primesep guard columns, available with all stationary phases, do not require holders. SIELC provides a method development service available to all customers. Inquire about our specially-tailored custom LC-phases for specific separations.

Select options
Application Analytes:
Acetaminophen (Paracetamol)

Application Detection:
UV Detection
SIELC Technologies usually develops more than one method for each compound. Therefore, this particular method may not be the best available method from our portfolio for your specific application. Before you decide to implement this method in your research, please send us an email to research@sielc.com so we can ensure you get optimal results for your compound/s of interest.