Novel SPE purification approach using the direct adsorption of vaporised propionic acid in food for rapid HPLC determination.

Solid phase extraction (SPE) is a technique widely used in food analysis for the isolation of analytes. Herein, we proposed a novel application of SPE to extract vaporised propionic acid, a common preservative, from a heated sample solution. A sample was heated under acidified conditions and the resulting steam was directly passed through an SPE column to extract the propionic acid, followed by elution and HPLC analysis.

[Internal Quality Control of Residual Pesticides Analysis Using Multiple Stable Isotope Labeled Compounds].

Internal quality control (IQC) is essential to ensure the reliability of the results of chemical analysis. In this study, we propose a novel method of IQC for multiresidue analysis of pesticides. A total of seven stable isotope labeled compounds (SILC) were added to analytical samples and were used to monitor and evaluate the quality of analytical results.

Combined use of a modifier gas generator, analyte protectants and multiple internal standards for effective and robust compensation of matrix effects in gas chromatographic analysis of pesticides.

In the analysis of pesticides performed with gas chromatography, the quantitative performance of measurements can be severely compromised by phenomena known as matrix effects. In seeking a solution to the problem of matrix effects, the application of a modifier gas generator (MGG) was investigated in this study, together with analyte protectants and multiple internal standards. Ethylene glycol (EG) was used as modifier gas and matrix effects in GCMS analysis were then evaluated by using the extracts of various food commodities.

Simultaneous determination of nine preservatives in food by liquid chromatography with the aid of coagulant in the clean-up process.

A simple HPLC method was developed for the simultaneous analysis of nine preservatives in food including benzoic acid, sorbic acid, dehydroacetic acid, methyl paraben, ethyl paraben, isopropyl paraben, propyl paraben, isobutyl paraben and butyl paraben. Samples were extracted with 60 v/v% methanol containing poly-aluminium chloride (PAC) and sodium hydroxide prior to analysis. PAC, which is normally used as a coagulant, was successfully applied to remove interfering substances from the samples.

[Development of a New Method for Determination of Sodium Saccharin and Acesulfame Potassium with the Aid of Coagulant].

An HPLC method for determination of sodium saccharin and acesulfame potassium was newly developed, employing coagulant pretreatment to remove particles dispersed in the sample extract. The method showed recovery of 96-101% for both analytes with a repeatability of less than 1% and a reproducibility of less than 2%. The limit of quantification for sodium saccharin was 0.

[Application of Coagulant in the Analysis of Lycorine and Galanthamine in Processed Foods].

Analytical method by HPLC and LC-MS/MS for determining lycorine and galanthamine in processed food was newly developed. In this method, coagulant which has never been used in food analysis was applied on cleanup process. With coagulant approach, removal of interfering substances on determination for analytes was easily achieved.

Purification and characterization of cellobiose dehydrogenase from white-rot basidiomycete Trametes hirsuta.

In order to save energy during the pulp making process, we tried to use white-rot basidiomycete, Trametes hirsuta, which degrades lignin efficiently. But a decrease in paper strength caused by cellulolytic activity ruled this out for practical application. Since the cellulolytic activity of the fungus must be decreased, we purified and characterized a cellobiose dehydrogenase (CDH) that was reported to damage pulp fiber.

Intron-dependent accumulation of mRNA in Coriolus hirsutus of lignin peroxidase gene the product of which is involved in conversion/degradation of polychlorinated aromatic hydrocarbons.

The homobasidiomycete Coriolus hirsutus coding sequences of a lignin peroxidase (LiP) gene (lip, containing six (I-VI) introns), a lip cDNA (lipc), and three lipc derivatives containing one (I), three (I-III), or five (I-V) introns were inserted into chromosome-integrating expression vector. These recombinant plasmids were introduced into C. hirustus monokaryotic strain.

Rat cytochrome P450-mediated transformation of dichlorodibenzo-p-dioxins by recombinant white-rot basidiomycete Coriolus hirsutus.

Rat cytochrome P450, CYP1A1, has been reported to play an important role in the metabolism of mono-trichlorodibenzo-p-dioxins (M-TriCDDs). To breed lignin (and M-TetraCDDs)-degrading basidiomycete Coriolus hirsutus strains producing rat CYP1A1, an expression cassette [C. hirsutus gpd promoter-C.

Transformation of the white-rot basidiomycete Coriolus hirsutus using the ornithine carbamoyltransferase gene.

An efficient transformation system for the basidiomycete Coriolus hirsutus was developed. A double-auxotrophic mutant of C. hirsutus, deficient both in ornithine carbamoyltransferase (OCTase) and 3-isopropylmalate dehydrogenase (3-IPM dehydrogenase), was transformed to Arg+ with each allelic type of the C.