Validação de método de cromatografia líquida para a determinação de sete ácidos graxos voláteis intermediários da digestão anaeróbia

Abstract

Volatile fatty acids (VFA) are important intermediate compounds that somehow indicate the efficiency of anaerobic systems. This paper presents results of method validation for seven VFA (C1 to C5) analysis in environmental samples by high performance liquid chromatography (HPLC). It was used an ion exclusion column kept at 55°C; injection volume of 10 μL and mobile phase (0.01 mol.L-1 H2SO4) at 0.6 mL.min-1. The validation criteria adopted were: limits of detection and quantification, that fell in the ranges of 5.0 -10 mg.L-1 and 15-30 mg.L-1, respectively; linearity (verified for all acids); repeatability and sensibility (very good for most acids); matrix effect (suppression effect observed for isobutyric acid) and accuracy (from 85 to 104%). Therefore, the operational conditions adopted seemed to be adequate and valid to measure VFA in samples from anaerobic reactors.