Publications by authors named "Tomoharu Fujiyoshi"

An inter-laboratory study involving 24 laboratories was conducted to validate the modified analytical method for the migration solution of heptane for the determination of bisphenol A migrating from polycarbonate food processing materials. In this study, two concentrations of samples were blindly coded. Each laboratory determined the analyte (bisphenol A, phenol and p-tert-butylphenol) concentration in each sample according to the established protocol.

View Article and Find Full Text PDF

A survey of the contamination of foods by sterigmatocystin (STC) was performed by an analytical method based on LC-MS/MS. STC was extracted from samples with acetonitrile/water (85/15, v/v) and then purified with immunoaffinity columns. The method was validated by a small-scale inter-laboratory study using spiked wheat samples.

View Article and Find Full Text PDF

The preservatives benzoic acid and sorbic acid are generally quantified with separation techniques, such as HPLC or GC. Here we describe a new method for determining these compounds in processed food samples based on a narrowness of the UV-visible spectral band width with derivative processing. It permits more selective identification and determination of target analytes in matrices.

View Article and Find Full Text PDF

The consequences of matrix effects in GC are a major issue of concern in pesticide residue analysis. The aim of this study was to evaluate the applicability of an analyte protectant generator in pesticide residue analysis using a GC-MS system. The technique is based on continuous introduction of ethylene glycol into the carrier gas.

View Article and Find Full Text PDF