A HPLC method for the quantification of butyramide and acetamide at ppb levels in hydrogeothermal waters

Abstract

A quantitative analytical method to determine butyramide and acetamide concentrations at the low ppb levels in geothermal waters has been developed. The analytes are concentrated in a preparation step by evaporation and analyzed using HPLC-UV. Chromatographic separation is achieved isocratically with a RP C-18 column using a 30 mM phosphate buffer solution with 5 mM heptane sulfonic acid and methanol (98 : 2 ratio) as the mobile phase. Absorbance is measured at 200 nm. The limit of detection (LOD) for BA and AA were 2.0 μg L⁻¹ and 2.5 μg L⁻¹, respectively. The limit of quantification (LOQ) for BA and AA were 5.7 μg L⁻¹ and 7.7 μg L⁻¹, respectively, at the detection wavelength of 200 nm. Attaining these levels of quantification better allows these amides to be used as thermally reactive tracers in low-temperature hydrogeothermal systems.