An enzyme linked immunosorbent assay (ELISA) has been developed & used to assay in lung secretions which was capable of measuring amoxicillin down to 10ng/ml25. High Performance Liquid Chromatography methods are commonly used to assay amoxicillin and its metabolites in biological fluids, nearly all reversed phase as for assay of drug substance and formulations25, 33. But the use of ion pairing is more common estimation method for biological fluids where separation from endogenous components may be aided by this technique25. A recent report by Fernandez‐Torres et al.,2010 showed that, an accurate and sensitive reversed‐phase high‐performance liquid chromatography –diode array–fluorescence (RP‐HPLC –DAD–FLD) analytical method for the quantitative determination of amoxicillin along with 10 other antibiotics and their main metabolites in urine
has been developed using, diode array (DAD) and fluorescence (FLD) detectors for analysis. The separation of the analyzed compounds was conducted by means of a C18 (150mm×4.6mm I.D., particle size 5μm) analytical column with C18 (4mm×4mm, particle
size 5μm) guard column. Analyzed drugs were determined within 34 minutes using formic acid 0.1% in water and acetonitrile in gradient elution mode as mobile phase