an air–assisted liquid–liquid microextraction method for the extraction and preconcentration of trace amounts of some synthetic phenolic antioxidants in biological fluids followed by their determination by gas chromatography–flame ionization detection has been reported. in this method the target analytes are extracted into a few microliters of carbon tetrachloride (extraction solvent) from an a...

A rapid, simple and sensitive high-performance liquid chromatography method was developed for determination of ciprofloxacin in plasma by means of ultraviolet detection. Ofloxacin was used as an internal standard and separation carried on a Novapak C18 column using a mobile phase of 0.01 M phosphate buffer (pH =2.6): methanol (82: 18 v/v). Extraction of drug was performed from plasma by liquid-...

Honey and propolis are rich in phenolic compounds, which act as natural antioxidants, and are becoming increasingly popular because of their potential role in contributing to human health. These compounds can also be used as indicators in studies into the floral and geographical origin of the honey and propolis themselves. We present here an overview of current analytical methods for measuring ...

We describe a complete procedure for separation and mechanized analysis of organic acids in human urine. The acid fraction of urine is separated by anion-exchange chromatography on diethylaminoethyl-Sephadex. Individual acids are identified and measured by use of a gas-chromatography/mass spectrometer/computer system that can clearly distinguish contributions from at least 150 substances in a s...