USP Method for the Analysis of Amoxicillin using the Legacy L1 Column


Application Notes: Amoxicillin is one of the most commonly prescribed antibiotics. It is often used for treating strep throat. According to USP methods, amoxicillin should not contain less than 900ug and no more than 1050ug of amoxicillin per mg.  The USP HPLC method for the separation of amitriptyline was developed on 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. Resolution between critical pairs corresponds to rules and specifications of UPS.

Application Columns: Legacy L1 C18 HPLC column

Application compounds: Amoxicillin

Mobile phase: MeCN/50 mM dibasic sodium phosphate

Detection technique: UV

Source: USP35: NF30 


Column Legacy L1, 4.6×150 mm, 5 µm, 100A
Mobile Phase MeCN/50 mM NaH2PO4  pH 5.0 (4/96)
Buffer NaH2PO4
Flow Rate 1.0 ml/min
Detection UV, 230 nm



Class of Compounds
Drug, Antibiotics, Hydrophobic, Ionizable
Analyzing Compounds Amoxicillin


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.

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Application Analytes:

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.