If you are looking for optimized HPLC method to analyze Hydrochlorothiazide 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.

Hydrochlorothiazide is a thiazide diuretic often considered the prototypical member of the class. It reduces the reabsorption of electrolytes from the renal tubules. This results in increased excretion of water and electrolytes, including sodium, potassium, chloride, and magnesium. It is used in the treatment of high blood pressure and swelling due to fluid build-up as well as several disorders such as edema, hypertension, diabetes insipidus, and hypoparathyroidism. Primesep 200, a reverse phase column, contains embedded acidic ionizable groups and can retain Hydrochlorothiazide. The method is UV compatible and can be used as a general approach for analyzing similar compounds.