Shuzo Taguchi

Simultaneous measurement of diazolidinyl urea, urea, and allantoin in cosmetic samples by hydrophilic interaction chromatography

A new HPLC method for simultaneous measurement of diazolidinyl urea (DU), urea, and allantoin by hydrophilic interaction chromatography using a column packed with triazol-bonded silica particles is described. The calibration curves of DU, urea, and allantoin were linear over the ranges 2.5-125.0, 30-1250, and 0.25-18.75mg/L, respectively. The recoveries of DU, urea, and allantoin from homemade cosmetic samples ranged from 92.84% to 101.69%, 98.19% to 103.22%, and 95.75% to 102.09%, respectively. The peak relative standard deviation (RSD) values for the recovery tests of 3 concentrations/5 replicates were 3.03% for all compounds. In day-to-day measurement of recovery tests from homemade lotions over 3 consecutive days, the RSDs were less than 2.5% in all cases. This method was well validated and would be helpful for quickly analyzing these compounds in cosmetic samples.

The different decomposition properties of diazolidinyl urea in cosmetics and patch test materials

Background. Diazolidinyl urea is a formaldehyde‐releasing compound that releases formaldehyde through its decomposition. However, there have been few reports about the decomposition properties of diazolidinyl urea in cosmetics and patch test materials.

新規ミニカラム及び光誘導化HPLCによる生落花生, コーン, そば粉及びとうがらし中のアフラトキシンの迅速分析

A rapid and clean method for the analysis of aflatoxins (AFs) was developed by using a new column and post-column photochemical derivatization HPLC with fluorescence detection. The new cleanup column consisted of magnesia and basic alumina poured on the top of a commercial multi-functional mini-column. It was extremely effective for the cleanup of AFs from raw peanut, corn, buckwheat and red pepper. Fluorescent substances, which interfered with the analysis of AFs from corn, were completely absorbed at the top of the magnesia layer. Recoveries of AFs (B1, B2, G1, G2) added to raw peanuts, corn, buckwheat and red pepper were over 80% at two levels of fortification (higher level: 10, 3, 10, 3 ng/g, respectively, lower level: 1.0, 0.3, 1.0, 0.3 ng/g, respectively). Coefficients of variation were smaller than 12%, except the lower fortified level for red pepper. Limits of detection for AFs in raw peanuts, corn and buckwheat were 0.3 ng/g for B1 and G1, and 0.1 ng/g for B2 and G2. Those in red pepper were 0.5 ng/g for B1, B2, G1 and G2.

Practical application of a monitoring system for environmental pollution by means of pattern analysis of ECD-sensitive substances.

Monitoring system for environmental ECD sensitive substances by means of capillary ECD gas chromatography (ECD-GC) was developed and applied to blue mussels as a model biological indicator. Thirty-three blue mussel taken from Osaka North Port, Osaka Misaki-cho and Hokkaido Funkawan Bay were analyzed. In addition, samples from Funkawan Bay were acclimated in the three different seawaters of Osaka North Port, Chiba and Yokohama and analyzed. Peak heights and retention times of capillary ECD-GC sensitive substances were recorded on the disk of personal computer. After retention times were transferred to retention indices for organochlorine compounds, detected components were quantified by using DDE as a standard. Common components were selected from the detected substances in order to prepare new data-file for pattern analyses. Calculation of similarity factors and cluster analysis were carried out on the patterns and the total concentrations of the common components. From these analyses, the differences and the changes of both quality and quantity of pollutants were clearly observed. The results showed that the developed system would be applicable to a repid monitoring method for environmental pollutants.