Review of methodology for the determination of benzimidazole residues in biological matrices.

The methods of analysis for sulphonamide residues in edible animal products are reviewed. Sulphonamides are widely used for therapeutic and prophylactic purposes in both humans and animals, sometimes as growth promoters as additives in animal feed. As a result of their widespread use, there is concern about whether the levels used of these drugs can generate serious problems in human health, e.g., allergic or toxic reactions. Several methods for the determination of sulphonamides have been reported in the literature and this review considers high-performance liquid chromatography (HPLC), liquid chromatography-mass spectrometry (LC/MS), gas chromatography (GC), thin-layer chromatography (TLC), high-performance capillary electrophoresis (HPCE), enzyme-linked immunosorbant assay (ELISA), biosensor immunoassay (BIA) and microbiological methods. Specific aspects of analysing sulphonamides, such as sample handling, chromatographic conditions and detection methods are discussed. Methods for drug residue monitoring should be accurate, simple, economical in both time and cost, and capable of detecting residues below the maximum residue limits (MRL). The current sulphonamide detection technologies are based on chromatographic methods or bacteriological growth inhibition. The instrumental methods such as HPLC and GC are both sensitive and specific, but are laborious and expensive. Because of the labour-intensive processes, only a few cases of GC methods applied to residue analysis have been published. These methods are suitable for confirmation but not for screening of large numbers of samples. Microbiological methods do not require highly specialized and expensive equipment. They also use highly homogeneous cell populations for testing and thus result in better assay precision. Although HPCE has powerful separation ability, the precision is poor and the instrument still needs to be improved. To date, this technique has not been widely applied to routine analysis. Currently, TLC has been almost replaced by other instrumental analysis. A rapid, sensitive and specific assay is required to detect positive samples in routine analysis, which can then be confirmed for the presence of sulphonamides by HPLC. Immunochemical methods such as ELISA can be simple, rapid and cost-effective, with enough sensitivity and specificity to detect small molecules. This review can be considered as a basis for further research aimed at identifying the most efficient approaches.

Analysis of sulphonamide residues in edible animal products: a review.

Determination of benzimidazole residues using liquid chromatography and tandem mass spectrometry.

Development of enantioselective gas chromatographic quantitation assay for dl-threo-methylphenidate in biological fluids.

Determination of benzimidazole anthelmintics in meat samples.

Gas-liquid chromatographic determination of sulphonamides

Determination of thiabendazole by electron-capture gas-liquid chromatography after reaction with pentafluorobenzoyl chloride.

Saccharin reacts quantitatively with phenothiazine (thiodiphenylamine) and copper(II) acetate dissolved in 50%V/V ethanol at 70 °C. The reaction product can be dissolved in an organic solvent and has a characteristic colour. The colour reaction is sensitive and the absorbance, at 510 nm, of the extract in 5 ml of xylene obeys Beer's law at saccharin concentrations between 20 and 400 µg ml–1. Cyclamates, sorbic acid, benzoic acid, 4-hydroxybenzoic acid and dehydroacetic acid do not interfere. Recoveries of saccharin from soft drinks were satisfactory. A procedure suitable for routine use is proposed.

Determination of saccharin in soft drinks by a spectrophotometric method

PROBLEM TO BE SOLVED: To provide a means and a method of safely processing the combustible gas left inside when stopping a fuel cell type power generation system. SOLUTION: When stopping the fuel cell type power generation system, a controller stops supply of the raw material gas and the fuel gas, and supplies an appropriate quantity of water to a reformer, and supplies an appropriate quantity of air for combustion to a combustor. An appropriate quantity of the water supplied to the reformer becomes steam, and gradually extrudes the combustible gas, which is left inside the fuel cell type power generation system, to the combustor. The combustible gas burns to be processed with an appropriate quantity of the air for combustion supplied from a blower fan. COPYRIGHT: (C)2005,JPO&NCIPI

Susumu Kobayashi

Papers

Gas-liquid chromatographic determination of sulphonamides

Determination of thiabendazole by electron-capture gas-liquid chromatography after reaction with pentafluorobenzoyl chloride.

Determination of saccharin in soft drinks by a spectrophotometric method

Fuel cell type power generation system, and method of stopping operation thereof

Microdetermination of o-phenylphenol in citrus fruits by gas-liquid chromatography