Liquid Chromatography With Fluorescence Detection Research Articles

High-performance liquid chromatography with fluorescence detection for the simultaneous determination of 3,4-methylenedioxymethamphetamine, methamphetamine and their metabolites in human hair using DIB-Cl as a label.

This paper describes a highly sensitive HPLC method for the simultaneous determination of 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), amphetamine (AP) and methamphetamine (MP) in human hair samples. The amphetamines investigated were derivatized with the fluorescent reagent, DIB-Cl to yield highly fluorescent DIB-derivatives, which were then analyzed by HPLC with fluorescence detection at excitation and emission wavelengths of 325 nm and 430 nm, respectively. The separation was achieved on an ODS column with an isocratic mobile phase composed of acetonitrile-methanol-water (30:40:30, v/v/v). The limits of detection for the four compounds obtained by the proposed method ranged from 11 to 200 pg/mg. The method was successfully applied to the determination of MDMA and MDA in hair samples obtained from MDMA abuser.

Determination of ochratoxin A in foods: state-of-the-art and analytical challenges.

Ochratoxin A (OTA) can occur in a large variety of commodities (cereals, beans, groundnuts, spices, dried fruits, coffee, beer, wine) and, because of a carry-over effect, in milk, pig blood, liver, and kidney, and poultry meat from animals fed with contaminated feed. Because of the persistence of OTA in the food chain, exposure to the compound is a potential human health hazard. This has prompted adoption of regulatory limits in several countries which, in turn, implies the development of suitable validated and official analytical methods and rapid screening tests for cost-effective food control on a large scale. Liquid chromatography with fluorescence detection (LC-FLD), coupled with immunoaffinity column (IAC) clean-up, is the most widely employed analytical technique. LC coupled with electrospray-ionization mass spectrometry (MS) has detection limits comparable with those of LC-FLD and the selectivity of IAC can be achieved by tandem (MS-MS) or sequential (MS(n)) detection. Synthetic counterparts to natural antibodies in the form of molecularly imprinted polymers seem a promising alternative to IAC for sample preparation. New analytical approaches to rapid, low-cost screening methods, for example those based on biosensors and dip-stick-like kits, are a direction in which innovation can be expected. Analytical methods for evaluation of the occurrence of OTA in foods, human exposure, and risk assessment are critically reviewed.