Dispersive Liquid-Liquid Microextraction of Famotidine and Nizatidine from Water Samples.

A new extraction method was developed for isolation of the antihistaminic drugs (histamine H2 receptor antagonists) famotidine (FMT) and nizatidine (NZT) from aqueous samples. A low solvent consumption method using dispersive liquid-liquid microextraction (DLLME) was applied for this purpose. The parameters of the isolation, namely, volume of extraction and disperser solvents, pH of sample and shaking time were optimized.

Application of Micellar Extraction for Isolation of Famotidine from Aqueous Samples Prior to its Chromatographic Determination.

Micellar extraction was applied to isolate famotidine from aqueous samples. This drug is an H receptor antagonist used for the treatment of stomach diseases. The process was performed with a mixture of anionic sodium dodecylsulfate and nonionic Triton X-114 surfactants.

Extraction of ranitidine and nizatidine with using imidazolium ionic liquids prior spectrophotometric and chromatographic detection.

A new extraction medium was proposed for liquid-liquid extraction of the histamine H2 receptor antagonists ranitidine (RNT) and nizatidine (NZT). The ionic liquids with low vapor pressure and favorable solvating properties for a range of compounds such as 1-butyl-3-methylimidazolium hexafluorophosphate [C4mim][PF6] and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [C4mim][Tf2N] were tested for isolation of analytes. The extraction parameters of RNT and NZT, namely, amount of ionic liquid, pH of sample solution, shaking and centrifugation time were optimized.

The usage of micellar extraction for analysis of fluvastatin in water and wastewater samples.

This work illustrates the development of new procedures for the isolation and preconcentration of fluvastatin (FLU) from aqueous solutions. Micellar extraction (ME) combined with high performance liquid chromatography (HPLC-UV) has been successfully applied for this purpose. It was found that the analyte created micelle with anionic sodium dodecylsulfate (SDS) and/or with the binary mixture of surfactants nonionic triton X114 (TX114) and cationic tetra-n-butyloammonium bromide (TBAB).

Quantification of ranitidine hydrochloride in the presence of its decomposition product by spectrophotometric methods. Application for kinetic study.

Three spectrophotometric methods, based on a spectral analysis, are proposed for quantification of ranitidine hydrochloride (RHCl) in the presence of its decomposition product (R-ox) without isolation from the matrix. One of them is a zero-crossing derivative-spectrophotometry. A value of the first derivative at 332 nm generated by the Savitzky-Golay algorithm (delta lambda = 22 nm and the first polynomial degree) allows for quantification of RHCI in the concentration range 0.

Applications of the extractive methods in chemical analysis of some psychotropic drugs.

The review is devoted for the solid phase extraction and the extractive spectrophotometric methods for the determination of some psychotropic drugs, e.g. phenothiazines, thioxanthenes, dibenzothiazines, fluoxetine, fluvoxamine, trazodone.

Spectrophotometric determination of olanzapine by its oxidation with N-bromosuccinimide and cerium(IV)sulfate.

Three simple spectrophotometric methods have been described for the assay of olanzapine in its pure and pharmaceutical formulations. The direct method (A) is based on the drug oxidation with excess of N-bromosuccinimide in acidic medium and the two indirect methods (B and C) are based on the oxidation of the drug with excess of N-bromosuccinimide and cerium(IV)sulfate, followed by the reaction of the unconsumed oxidants with celestine blue. The calibration graphs were linear over the range 10 - 120 microg mL(-1) (method A), 0.

Analytical application of the reactions of amitriptyline with eriochrome cyanine R and pyrocatechol violet.

Eriochrome cyanine R (ECR) and pyrocatechol violet (PCV) have been tested as reagent for the determination of amitriptyline (AMT). They react in aqueous media with AMT forming coloured compounds sparingly soluble in walter. Optimal conditions for the reaction have been established and new extractive-spectrophotometric methods have been developed for the determination of amitriptyline.

The use of the new SPE methods for isolation of some tricyclic antidepressant drugs from human serum.

Solid-phase extraction (SPE) methods were applied to isolation of amitriptyline (AMI), imipramine (IMI) and chlorprothixene (CPX) from blood human serum. SPE was carried out using the octadecyl (C(18)) column for isolation of AMI and cyclohexyl (CH) columns in the case of IMI and CPX. The spiked serum samples were used to examine the recoveries of these drugs from C(18) and CH sorbent materials.

Studies and analytical application of reaction of imipramine with chrome azurol S.

Chrome azurol S (CAS) was tested as a spectrophotometric reagent for the determination of imipramine (IMP). It reacts in aqueous media with IMP forming pink-red, sparingly soluble in water ion association compound. This compound was quantitatively extracted with chloroform and the absorbance of organic phase was measured at 510 nm.

[Methods of determination of fluoxetine nad fluvoxamine].

Two selective serotonin reuptake inhibitors (SSRIs) have been introduced: fluoxetine and fluvoxamine. The literature review shows most methods allow quantitative determination of SSRIs pharmaceutical preparations and plasma, in the lower ng/ml range and that they are, therefore, suitable for therapeutic drug monitoring purposes of this category of drugs. Most procedures are based on investigation of this drugs by spectrophotometric, electrochemical and chromatographic procedures with detection by various detectors.

Simultaneous LC determination of some antidepressants combined with neuroleptics.

A reversed-phase HPLC method with UV detection at 252 nm is presented for the simultaneous determination of some tricyclic antidepressants (amitriptyline, imipramine) and neuroleptics (chlorprothixene, thioridazine) in their quaternary mixtures. Sample analysis was performed on a bonded reversed phase C-18, 5 microm, 250 x 4.6 mm ID (Lichrospher 100RP-18) column using acetonitrile and 0.