Hiroyuki Ohno

2-Ethyl-1-hexanol in Indoor Air as a Possible Cause of Sick Building Symptoms.

Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya City Public Health Research Institute, Department of Medical Technology, Nagoya University School of Health Sciences, Department of Environmental Dermatology, Nagoya University School of Medicine, Second Department of Internal Medicine, Nagoya University School of Medicine and Research Center for Radiation Emergency Medicine, National Institute of Radiological Sciences, Japan

Isolation and Quantification of Polyamide Cyclic Oligomers in Kitchen Utensils and Their Migration into Various Food Simulants

Small amounts of cyclic monomers and oligomers are present in polyamide (PA)-based kitchen utensils. In this study, we isolated eight PA-based cyclic monomers and oligomers from kitchen utensils made from PA6 (a polymer of ε-caprolactam) and PA66 (a polymer of 1,6-diaminohexane and adipic acid). Their structures were identified using high-resolution mass spectrometry and 1H- and 13C-nuclear magnetic resonance spectroscopy, and their residual levels in PA-based kitchen utensils and degree of migration into food simulants were quantified by high-performance liquid chromatography/mass spectrometry using purchased PA6 monomer and isolated PA66 monomers, and isolated PA6 and PA66 oligomers as calibration standards. Their total residual levels among 23 PA-based kitchen utensils made from PA6, PA66, and copolymers of PA6 and PA66 (PA6/66) ranged from 7.8 to 20 mg/g. Using water, 20% ethanol, and olive oil as food simulants, the total migration levels of the PA monomers and oligomers ranged from 0.66 to 100 μg/cm2 under most examined conditions. However, the total migration levels of the PA66 monomer and oligomers from PA66 and PA6/66 kitchen utensils into 20% ethanol at 95°C were very high (1,700 and 2,200 μg/cm2, respectively) due to swelling by high-temperature ethanol.

[Interlaboratory study on migration test of antimony and germanium for food-contact polyethylene terephthalate].

An interlaboratory study was performed to evaluate a migration test method of antimony (Sb) and germanium (Ge), based on the Japanese Food Sanitation Law for food- contact polyethylene terephthalate. Eighteen laboratories participated, and quantified Sb and Ge in three test solutions as blind duplicates using graphite furnace atomic absorption spectrometry (GF-AAS), inductively coupled plasma-optical emission spectrometry (ICP-OES) or induced coupled plasma-mass spectrometry (ICP-MS). Statistical analysis revealed that the trueness, repeatability and reproducibility were 98-107%, 1.7-7.5% and 2.0-18.8% by using GF-AAS and ICP-OES. The performance of these methods is sufficient for testing the specifications. The performance parameters of ICP-MS were 99-106%, 0.7-2.2% and 2.2-10.5%, respectively. ICP-MS is available as an alternative measuring method. However, in some laboratories, the quantitative values of Sb were higher than the addition levels. We found that Sb in working solutions is absorbed on glass vessels. Careful control of concentration in working solutions is required for Sb analysis.

Performance comparison of material tests for cadmium and lead in food contact plastics

Based on the Japanese Food Sanitation Law, the performances of official and alternative material test methods for cadmium (Cd) and lead (Pb) in food contact plastics were compared. Nineteen laboratories participated to an interlaboratory study, and quantified Cd and Pb in three PVC pellets. in the official method, a sample is digested with H2SO4, taken up in HCl, and evaporated to dryness on a water bath, then measured by atomic absorption spectrometry (AAS) or inductively coupled plasma-optical emission spectrometry (ICP-OES). Statistical treatment revealed that the trueness, repeatability (RSDr) and reproducibility (RSDr) were 86-95%, 3.1-9.4% and 8.6-22.1%, respectively. The values of the performance parameters fulfilled the requirements , and the performances met the test specifications. The combination of evaporation to dryness on a hot plate and measurement by AAS or ICP-OES is applicable as an alternative method. However, the trueness and RSDr were inferior to those of the official method. The performance parameters obtained by using the microwave digestion method (MW method) to prepare test solution were better than those of the official method. Thus, the MW method is available as an alternative method. Induced coupled plasma-mass spectrometry (ICP-MS) is also available as an alternative method. However, it is necessary to ensure complete digestion of the sample.

Interlaboratory Study on Evaporation Residue Test for Food Contact Products (Report 1)

An interlaboratory study was performed to evaluate the equivalence between an official method and a modified method of evaporation residue test using three food-simulating solvents (water, 4% acetic acid and 20% ethanol), based on the Japanese Food Sanitation Law for food contact products. Twenty-three laboratories participated, and tested the evaporation residues of nine test solutions as blind duplicates. For evaporation, a water bath was used in the official method, and a hot plate in the modified method. In most laboratories, the test solutions were heated until just prior to evaporation to dryness, and then allowed to dry under residual heat. Statistical analysis revealed that there was no significant difference between the two methods, regardless of the heating equipment used. Accordingly, the modified method provides performance equal to the official method, and is available as an alternative method.

Interlaboratory Study on Caprolactam Test for Food-Contact Nylon Products

The Japanese Food Sanitation Law sets a limit on the migration level of caprolactam for food-contacting nylon products. Here, we carried out an interlaboratory study in twenty laboratories to evaluate the performance of the official GC-FID test method and a GC-MS method as an alternative test method to the official method. Each laboratory quantified caprolactam in three test solutions in 20% ethanol as blind duplicates using GC-FID or GC-MS. The official method (GC-FID with absolute calibration) gave trueness, repeatability (RSDr) and reproducibility (RSDr) values of 96-97%, 3.3-5.4% and 4.0-6.7%, respectively. These values met the target criteria (trueness: 80-110%, RSDr: 10%, RSDr: 25%). The performance of the method was further improved by the introduction of heptalactam as an internal standard. As for GC-MS method, some values of the RSDr exceeded 10% when absolute calibration was used. However, when an internal standard was introduced, the trueness, RSDr and RSDr of GC-MS method were all acceptable at 94-96%, 2.0-4.4% and 7.0-9.4%, respectively. Therefore, GC-MS with an internal standard is available as an alternative test method to the official method.

Identification and Quantitation of Volatile Organic Compounds in Poly(methyl methacrylate) Kitchen Utensils by Headspace Gas Chromatography/Mass Spectrometry.

A headspace GC/MS method was developed for identification and quantitation of residual volatile organic compounds in poly(methyl methacrylate) (PMMA) kitchen utensils. A sample was cut into small pieces, then N,N-dimethylacetamide was added in a headspace vial and sealed. After storing for more than 1 day at room temperature, the vial was incubated for 1 h at 90°C, and the headspace gas was analyzed by GC/MS. In 24 PMMA kitchen utensils, 16 volatile organic compounds including methyl methacrylate, methyl acrylate, toluene, 2-methyl-1-butene, 2-methyl-2-butene, 2-methylpropanal, methyl propionate, methyl isobutyrate, trans-3-heptene, heptane, cis-3-heptene, trans-2-heptene, cis-2-heptene, 2,4,4-trimethyl-1-pentene, 2,4,4-trimethyl-2-pentene, and 1-octene were identified and quantitated. These 15 volatile compounds except methyl methacrylate were found for the first time in PMMA kitchen utensils. Recovery rates from spiked samples were 97.4-104.0% with CV values of 2.8-9.6%. Samples contained 190-7900 μg/g of methyl methacrylate, 26-810 μg/g of methyl acrylate, and 2-1300 μg/g of toluene; other compounds were at levels less than 100 μg/g. Methyl methacrylate was the main monomer of PMMA and methyl acrylate was a comonomer; toluene should be used as a solvent.

Changes of Free Formaldehyde Quantity in Non-iron Shirts by Washing and Storage

Many non-iron shirts are finished with formaldehyde (HCHO) resin or HCHO vapor. Free HCHO in the non-iron shirt mostly decreases by washing. However, free HCHO sometimes increases once again with time by decomposition of resin. We have measured the quantity of free HCHO in 27 non-iron shirts and 3 regular shirts as control samples, before and after washing and drying, 1 week, 2 weeks, 1 month and 6 months after washing. Consequently, before washing, the quantity of free HCHO in 8 non-iron shirts was found to exceed 75ppm, max up to 202ppm. Seventy-five ppm is the standard value detected in underwears for adults according to the Law for the Control of Household Products Containing Harmful Substances. Even after washing, the quantity of free HCHO in 2 non-iron shirts did not fall below 75ppm. And after the storage for 6 months, the quantity of free HCHO in 7 non-iron shirts exceeded 75ppm. Six months after triple washing, the quantity of free HCHO in 5 non-iron shirts exceeded 75ppm. Our study revealed that the patterns of change in the quantity of free HCHO were dependent on the types of finishing.

A micro diffusion analysis of MeOH in house hold aerosol commodities.

A simpler procedure for the routine measurement of methanol (MeOH) in house hold aerosol commodities was studied by the microdiffusion analysis. MeOH in the aerosols was converted to formaldehyde (HCHO) by potassium permanganate in an outer ring of Conway microdiffusion cells. The HCHO is absorbed in 0.1% methylbenzothiazolinonehydrazone (MBTH) solution of a center portion by means of diffusion in the cells standing for 4 h. at 40°C. To the solution of the center portion is added 1 ml of 5% ferric ammonium sulfate solution for color development. This procedure is available in screening of many samples examined for MeOH comparing the colors between the tested and standard solution. The samples positive toward MeOH are further examined by gas chromatography. A minimum amount of MeOH detectable by this method was 0.1 mg/g (sample).