[Development of identification method for isopropyl citrate].

In Japan's Specification and Standards for Food Additive, 8th edition, two identification tests involving isopropyl citrate for detecting isopropyl alcohol and citrate are stipulated. However, these identification tests use mercury compound, which is toxic, or require a time-consuming pretreatment process. To solve these problems, an identification test method using GC-FID for detecting isopropyl alcohol was developed.

Estimation of daily aluminum intake in Japan based on food consumption inspection results: impact of food additives.

Dietary aluminum (Al) intake by young children, children, youths, and adults in Japan was estimated using the market basket method. The Al content of food category (I-VII) samples for each age group was determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The Al content in processed foods and unprocessed foods ranged from 0.

Absolute quantification of dehydroacetic acid in processed foods using quantitative ¹H NMR.

An absolute quantification method for the determination of dehydroacetic acid in processed foods using quantitative (1)H NMR was developed and validated. The level of dehydroacetic acid was determined using the proton signals of dehydroacetic acid referenced to 1,4-bis (trimethylsilyl) benzene-d4 after simple solvent extraction from processed foods. All the recoveries from three processed foods spiked at two different concentrations were larger than 85%.

[Study of purity tests for silicone resins].

In the 8th edition of Japan's Specifications and Standards for Food Additives, the purity test for silicone resins requires the determination of the refractive index and kinetic viscosity of the extracted silicone oil, and allows for only a limited amount of silicon dioxide. In the purity test, carbon tetrachloride is used to separate the silicone oil and silicon dioxide. To exclude carbon tetrachloride, methods were developed for separating the silicone oil and silicon dioxide from silicone resin, which use hexane and 10% n-dodecylbenzenesulfonic acid in hexane.

[Improved methodology for quantitative determination of thiabendazole].

The method prescribed in the 8th edition of Japan's Specifications and Standards for Food Additives (JSSFA) for the quantitative analysis of thiabendazole was improved by eliminating the use of toxic reagents such as mercuric acetate and chromium trioxide. For exclusion of mercuric acetate, a nonaqueous titration was performed using four types of solvent systems, including acetic acid:acetic anhydride (1:5), acetic acid:acetic anhydride (3:7), acetic acid alone, and formic acid:acetic acid (1:10), that did not contain mercuric compounds. Because precipitates were formed in titrations using acetic acid alone and formic acid:acetic acid (1:10), we considered that it was difficult to determine the purity using these solvent systems.

[Analytical method for natamycin in wine using high-performance liquid chromatography].

An analytical method was developed for determining amount of natamycin in wine using a C18 minicartridge column and high-performance liquid chromatography (HPLC) with photodiode array (PDA) detection. Natamycin purified from wine was identified in accordance with the retention time and UV spectrum obtained from PDA detection. The limit of quantification of natamycin in wine was estimated as 0.

[Analysis of hexachlorobenzene in Food Red Nos. 104 (phloxine) and 105 (rose Bengal) by GC-ECD].

A simple and rapid method using electron capture detector gas chromatography (GC-ECD) was developed for the determination of hexachlorobenzene (HCB) in Food Red Nos. 104 and 105. The sample was dissolved in water and HCB was extracted with hexane.

Quantitative nuclear magnetic resonance spectroscopic determination of the oxyethylene group content of polysorbates.

Guidelines for the oxyethylene group (EO) content of polysorbates are set by the Food and Agriculture Organization/World Health Organization Joint Expert Committee on Food Additives. However, the classical titration method for EO determination is difficult and time-consuming. Here, we show that quantitative (1)H-nuclear magnetic resonance spectroscopy can determine the EO contents of polysorbates rapidly and simply.

Application of liquid chromatography-nuclear magnetic resonance spectroscopy for the identification of ethyldimethylpyrazine, a food flavouring agent.

The application of liquid chromatography-nuclear magnetic resonance spectroscopy (LC-NMR) for the direct identification of ethyldimethylpyrazine, a food flavouring agent, has been studied. The commercial product is a mixture of two regio-isomers, 2-ethyl-3,5-dimethylpyrazine (1) and 2-ethyl-3,6-dimethylpyrazine (2); however, the exact composition of the mixture is unknown. Structural characterization by LC-MS and GC-MS was not possible because both regio-isomers yield the same molecular related ion and ion fragmentation.