Determination of prostaglandins in human seminal fluid by solid-phase extraction, pyridinium dichromate derivatization and high-performance liquid chromatography

Semi-automated solid-phase extraction procedure for the high-performance liquid chromatographic determination of alinastine in biological fluids

A solid-phase extraction (SPE) method for sample clean-up followed by a reversed-phase HPLC procedure for the assay of alinastina (pINN) in biological fluids is reported. The effects of the sample pH, composition of the washing and elution solvents and the nature of the SPE cartridge on recovery were evaluated. The selectivity of SPE was examined using spiked rat urine and plasma samples and the CH and PH cartridges gave rise to the cleanest extracts. The recoveries obtained in spiked rat urine and plasma samples were 91.2+/-2.7 and 99.9+/-2.8%, respectively. The proposed SPE method coupled off-line with a reserved-phase HPLC system with fluorimetric detection was applied to the quantitation of alinastine in real rat urine samples. The analytical method was also applied and validated for the determination of alinastine in dog plasma. The recovery from spiked dog plasma samples using the PH cartridge was around 65%. The within-day and between-day precisions were 7 and 12%, respectively. The detection and quantitation limits in dog plasma were 0.024 and 0.078 microg/ml, respectively.

Analysis of prostaglandins by micellar electrokinetic capillary chromatography

This paper presents a rapid and reliable micellar electrokinetic capillary chromatography (MEKC) method to separate major prostaglandins and thromboxane B2. The running buffer was modified with sodium dodecyl sulfate (SDS). The effects of the SDS concentration on the migration behavior of analytes was also examined. Moreover, the influences of electrolyte concentration and capillary temperature on the separation were investigated. In optimum conditions, seven major prostaglandins and thromboxane B2 could be separated within 8 min. The relative standard deviations of the migration times (reproducibility) of the analytes were less than 0.82%.

Use of derivatization to improve the chromatographic properties and detection selectivity of physiologically important carboxylic acids

In this review, tagging techniques with reagents used for ultraviolet-visible (UV-Vis), fluorescent (FL), chemiluminescent (CL) and electrochemical detection (ED) for higher carboxylic acids in HPLC are evaluated in terms of the tagging reactions, handling, flexibility, stability of the reagents and the corresponding derivatives, sensitivity and selectivity. Emphasis is given to the applications of these tagging techniques to biologically important carboxylic acids of relatively high molecular mass including free fatty acids, prostaglandins, leukotrienes and thromboxanes etc. Some typical examples are described. Although RIA and GC-MS are powerful techniques for the highly sensitive determination of carboxylic acids, tagging for these techniques is not included in this review because recent progress in tagging methods has been mainly concerned with HPLC detection.

Solid-phase extraction technique for the analysis of biological samples

This article reviews the literature on solid-phase extraction published in the last 10 years. Emphasis has been placed on dealing with samples of biological origin. The sections consist of introduction, history and development, types of columns, selection of a suitable column, types of samples, advantages and applications.