If you are looking for optimized HPLC method to analyze Alendronic Acid check our HPLC Applications library

For optimal results in HPLC analysis, it is recommended to measure absorbance at a wavelength that matches the absorption maximum of the compound(s) being analyzed. The UV spectrum shown can assist in selecting an appropriate wavelength for your analysis. Please note that certain mobile phases and buffers may block wavelengths below 230 nm, rendering absorbance measurement at these wavelengths ineffective. If detection below 230 nm is required, it is recommended to use acetonitrile and water as low UV-transparent mobile phases, with phosphoric acid and its salts, sulfuric acid, and TFA as buffers.
For some compounds, the UV-Vis Spectrum is affected by the pH of the mobile phase. The spectra presented here are measured with an acidic mobile phase that has a pH of 3 or lower.

Dronic acids are bisphosphonates that differ in their alkyl chains. Alendronate (Fosamax) marketed alone is used for osteoporosis and other bone diseases. It is also combined with Vitamin C (Fosavance). A short, 50 mm Primesep SB column separates alendronic, ibandronic, and etidronic acids. The HPLC separation uses a mobile phase of water, acetonitrile (MeCN, ACN), trifluoracetic acid (TFA) or ammonium formate and evaporative light scattering detection (ELSD) at 80°C.