A method is presented for magnetic solid phase extraction of tartrazine from nonalcoholic beverages. The method involves the extraction and clean-up by activated carbon covered with magnetite dispersed in the sample, followed by the magnetic isolation and desorption of the analyte by basified methanol. The tartrazine eluted from the magnetic support was determined by spectrophotometry. Under op...

Gabapentin is an anticonvulsant widely used in the treatment of epilepsy. No peculiar chromophore is available on the gabapentin moiety for direct analysis by absorption spectrophotometry. A sensitive spectrophotometric method for the determination of gabapentin in bulk, pharmaceutical formulations and human plasma has been developed. In this method, gabapentin directly derivatized with vanilli...

Adequate function of the retina is dependent on proper oxygen supply. In humans, the inner retina is oxygenated via the retinal circulation. We present a method to calculate total retinal oxygen extraction based on measurement of total retinal blood flow using dual-beam bidirectional Doppler optical coherence tomography and measurement of oxygen saturation by spectrophotometry. These measuremen...

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 ...

A new method of indirect determination of Cu(2+) was developed based on square-wave voltammetry by the oxidation of iodide in organic solvent at the liquid/liquid (L/L) interface. The limit of detection for the determination of Cu(2+) in this method was found to be 5 x 10(-4) mol/L, and the concentration ranged up to 1 x 10(-2) mol/L gave a linear limiting current versus concentration response....

Conventional RNA isolation methods optimised for pine seedlings have been shown to produce poor quality RNA when applied to needles of adult pine trees. We describe here a modified procedure to isolate high pure RNA from needles of thirty-year-old maritime pines, exhibiting high levels of phenolics, polysaccharides and RNases. Major changes were the inclusion of proteinase K in the extraction m...