USP Methods for the Analysis of Guaifenesin Using a Legacy L1 Column


Application Notes: Guaifenesin is common, over the counter expectorant. Guaifenesin contain no less than 98 percent and not more than 102 percent of the labeled amount of guaifenesin calculated on a dried basis, according to the USP methods. the The USP HPLC method for the analysis of guaifenesin was developed on our Legacy L1 column according to the US Pharmacopeia methodology. L1 classification is assigned to reversed-phase HPLC column containing C18 ligand. Support for the material is spherical silica gel with particles size 3-10 um and pore size of 100-120A.

Application Columns: Legacy L1 C18 HPLC column

Application compounds: Guaifenesin, benzoic acid

Mobile phase: MeOH/H2O/AcOH 40:60:1.5

Detection technique: UV

Reference: USP 35- NF30



Column Legacy L1, 4.6×150 mm, 5 µm, 100A
Mobile Phase MeOH/H2O/AcOH 40/60/1.5
Buffer NaH2PO4
Flow Rate 1.0 ml/min
Detection UV, 270 nm



Class of Compounds
Drug, Antibiotics, Hydrophobic, Ionizable, Acid
Analyzing Compounds Guaifenesin, Benzoic acid


Application Column

SIELC Legacy L1 HPLC column

Legacy L1

SIELC's family of Legacy columns is based on the United States Pharmacopeia's (USP) published chromatographic methods and procedures. Numerous brands have columns used in USP reference standards and methods. USP has created various designations to group together columns with similar types of packing and properties in the solid phase. SIELC's Legacy columns adhere to these strict requirements and properties, allowing you to easily replace older columns that are no longer available without needing to significantly modify your method or SOPs.

Select options
Application Analytes:
Benzoic Acid

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 so we can ensure you get optimal results for your compound/s of interest.