Determination Of Phenylacetic Acid Research Articles

Determination of phenyl acetic acid by cyclic voltammetry with electrochemical detection

The phenyl acetic acid (PAA) has been determined by cyclic voltammetry with electrochemical detection using CuGeO3 nanowires as the glassy carbon electrode (GCE) modified materials. The electrochemical behaviors of the PAA at the CuGeO3 nanowire modified GCE in neutral solution show that two pairs of electrochemical CV peaks are observed. Two anodic CV peaks are located at 0.31V and −0.02V for cv peak 1 and cv peak 2, respectively. The intensities of two anodic peaks vary linearly with the increase of the PAA concentrations from 0.01 to 2mM. The detection limit is 82.1μM and 9.1μM for cv peak 1 and cv peak 2, respectively. The CuGeO3 nanowire modified GCE exhibits good reproducibility, stability and sensibility.

Gas Chromatographic — Mass Spectrometric Determination of Phenylacetic Acid in Human Blood

Phenyl acetic acid, a metabolite of 2-phenyl ethylamine, acts as a neuromodulator in the nigrostriatal dopaminergic pathway stimulating the release of dopamine. The evaluation of phenyl acetic acid concentration in the biological fluid reflects phenyl ethylamine levels thus allowing the assessment of the modulatory role of this endogenous substance. Changes in biological fluids levels of 2-phenylethylamine and/or in its metabolite have been reported in affective disorders, such as depression and schizophrenia. Recently, the occurrence of the "attention deficit hyperactivity syndrome" has been frequently reported in childhood population and involvement of dopaminergic dysfunction in this disease has been suspected. A fast, reliable and reproducible method for the determination of phenyl acetic acid in human blood, is therefore needed in order to have a screening tool for monitoring both healthy childhood population and suspected "attention deficit hyperactivity syndrome" patients. The gas chromatographic-mass spectrometric method here described makes use of a deuterated internal standard in order to overcome problems related to the lack of reproducibility often encountered when a derivatization step is performed.

Simple HPLC Method for Routine Determination of Urinary Phenylacetic Acid Excretion

Abstract A simple and reliable isocratic reversed-phase HPLC method for the determination of phenylacetic acid (PAA) in urine is described. After acid hydrolysis of its glutaminoconjugate, phenylacetic acid is extracted by diethylether; chromatography is followed by UV detection at 210 nm. This rapid method is quite specific and sufficiently sensitive. We found satisfactory linearity up to 200 mg/1 PAA urinary concentrations. Within-day and between-day assays showed variation coefficients below 10 %. Twenty-four hour urinary excretion of PAA might therefore be easily and routinely measured; it could represent a noninvasive and suitable biological marker in psychiatry.

High-performance liquid chromatographic determination of phenylacetic acid in human plasma extracted with ethyl acetate

This paper describes a high-performance liquid chromatographic method with ultraviolet detection for measuring plasma phenylacetic acid. This simple and reliable method consists of an acid hydrolysis of conjugated phenylacetic acid before extraction with an organic solvent: washed ethyl acetate saturated in sodium chloride. The recovery of extraction was estimated by internal standardization with phenylpropionic acid, and validated by addition of phenylacetic acid standards. A preliminary application to plasma phenylacetic acid in patients suffering from depression is described.

ガスクロマトグラフィー/陰イオン化学イオン化質量分析法によるラット脳内フェニル酢酸の定量

ガスクロマトグラフィー/陰イオン化学イオン化質量分析法によるラット脳内フェニル酢酸の定量

Determination of phenylacetic acid in cerebrospinal fluid by gas chromatography-mass spectrometry.

Using gas chromatography-mass spectrometry, we developed a sensitive and reliable technique to measure phenylacetic acid (PAA), an oxidatively deaminated metabolite of beta-phenylethylamine (PEA), in small amounts of cerebrospinal fluid (CSF). In a preliminary analysis, PAA concentrations in depressive patients were significantly lower than those in controls, while there were no differences in PAA levels between schizophrenic patients and controls. This suggests a possible link between the decreased PEA metabolism in the brain and the etiology of depression. However, further studies are needed to clarify the effects of neuroleptics and antidepressants on PAA levels in CSF, since the samples were obtained without regard to medication in the present study. In control subjects, a U-shaped distribution was obtained when the values of PAA were plotted as a function of age. There were no sex differences and no significant concentration gradients in CSF PAA levels.

Determination of Phenylacetic Acid in Penicillin Fermentation Media by Means of Gas Chromatography.

Determination of Phenylacetic Acid in Penicillin Fermentation Media by Means of Gas Chromatography.

Determination of Phenylacetic Acid and Phenylacetamides in Samples from Penicillin Fermentations

Determination of Phenylacetic Acid and Phenylacetamides in Samples from Penicillin Fermentations