Security control is becoming a major global issue in strategic locations, such as airports, official buildings, and transit stations. The agencies responsible for public security need powerful and sensitive tools to detect warfare agents and explosives. Volatile signature detection is one of the fastest and easiest ways to achieve this task. However, explosive chemicals have low volatility maki...

A novel stability-indicating high-performance liquid chromatographic assay method was developed and validated for valacyclovir in the presence of degradation products generated from forced decomposition studies. A Hypersil ODS C-18 (250 x 4.6 mm, packed with 5 micron) column in an isocratic mode with the mobile phase acetonitrile: phosphate buffer (pH3.6) (50:50%v/v) was used. The flow rate was...

CLINICAL CHEMISTRY, Vol. 29, No. 2, 1983 407 cause a “rise” (an increase in absorbance over a threshold indicative of a sample peak) in the AST blank channel. The concentration of metronidasole in the primer is critical; too little and the blank channel shows no rise; too much and the AST activity in the test channel isapparently so depressed by the drug that the trigger level (threshold) is no...

We describe a sensitive and specific liquid-chromatographic assay for pentoxifylline and three of its metabolites in human plasma and urine. Addition of hydrochloric acid to the sample before extraction, and incorporation of acetic acid in the chromatographic eluent, allow the simultaneous determination of the four compounds plus an internal standard in one chromatographic run. Unlike gas-chrom...

We estimated glycated ("glycosylated") hemoglobin in erythrocytes of hemodialyzed uremic patients by the aminophenylboronic acid affinity-chromatographic method and by an ion-exchange chromatographic method. As expected, apparent HbA1 concentrations were above normal in the uremic patients, owing to interference by the carbamylated hemoglobin. However, there was no significant difference betwee...

A high-performance liquid chromatographic method was developed for the analysis of capsaicinoid compounds, the pungent principles of capsicum fruits. A sequential simplex method was applied to optimize the chromatographic response function used to assess the quality of separation by varying the chromatographic parameters. The separation was achieved in 11 min using a C-8 column of 15-cm length ...

A fast method to obtain a quantitative structure-retention relationship is required in chromatography for the rapid optimization of chromatographic separation conditions. Chromatographic data of acidic drugs are analyzed by a computational chemical method to simulate chromatographic simulation. The direct interaction between a model phase and a drug is calculated as an energy value using the mo...

in recent years considerable interest has been focused on the plasma amino acid patterns as a possible index of protein malnutrition, in children. thus a change in the ratio of non-essential to essential amino acids is considered to be significant in the development of protein malnutrition. the present paper reports a simplified and rapid chromatographic procedure for the determination of this ...

An isocratic RP-HPLC method (Method-A) and two visible spectrophotometric methods (Method B and C) were developed and validated for the determination of Clobazam in bulk and tablet dosage forms. In Method-A, a PEAK chromatographic system equipped with Zodiac C-18 (250mm, 4.6mm and 5μm) column, mobile phase of composition 10:30:60 (v/v/v) of tetra hydro furan (THF), methanol (MeOH) and acetonitr...

In this paper, chromatographic analysis of active substance olopatadine hydrochloride, which is used in eye drops as antihistaminic agent, and its impurity E isomer by hydrophilic interaction liquid chromatography (HILIC) and application of design of experiments (DoE) methodology are presented. In addition, benzalkonium chloride is very often used as a preservative in eye drops. Therefore, the ...