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...

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...

Solid-phase spectrophotometry has been applied to analysis for trace amounts of vanadium. Vanadium was sorbed in a styrene-divinylbenzene-type anion-exchanger Dowex 1-X8 as a vanadium-4-(2-pyridylazo)resorcinol complex. Resin phase absorbances at 562 and 800 nm were measured directly which allowed the determination of vanadium in the range of 0.1-2.4 ng/ml with a RSD of 1.5%. The method has bee...

A method for the speciation of selenium (IV) based on solid-phase spectrophotometry (SPS), has been developed. In acidic conditions selenium (IV) oxidizes potassium iodide and the I(3)(-) forms an ionic association with Rhodamine B (RB) which is fixed on a dextran type lipophilic gel. The gel phase absorbances at 590 and 800 nm are measured directly, and allows for the determination of selenium...

Procedures for the photothermal lens determination of metals and organic compounds, on the basis of solid-phase mesoporous optical-sensing materials (polymethacrylate [PMA]) matrices with immobilized reagents, were developed. These procedures combine (i) selective and efficient preconcentration of trace substances to be analyzed in specially designed and synthesized transparent mesoporous PMA p...

A simple and sensitive solid-phase spectrophotometry procedure was improved for the microdetermination of Cr(VI). A 0.06 cm3 portion of a cation exchanger, Muromac AG 50W-X2, was used to concentrate the target Cr(VI) in a 20 cm3 water sample, and resin beads were introduced in a flow cell of 1.5 mm diameter and having a 10 mm light path length for measurements using a UV-visible spectrophotomet...

A sensitive preconcentration procedure for spectrophotometeric determination of aluminum was developed. Aluminum as aluminon complex is adsorbed on microcrystalline naphthalene. The naphthalene containing the complex is dissolved in 3 mL of acetone and its absorbance is measured at 544 nm. The effect of various factors on the preconcentration of aluminum was investigated. The calibration graph ...

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...