[Plasticizers Used in Polyvinyl Chloride Toys (2019-2020)].

We determined the fifteen types of plasticizers, including four kinds of phthalic acid esters (PAEs) used in 220 polyvinyl chloride (PVC) toys on Japanese market from 2019 to 2020. Three kinds of previously undetected types of PAEs were also detected, but not identified in this study. Di (2-ethylhexyl) terephthalate (DEHTP) was the highest detection rate in 209 soft PVC toys out of 220 toys, with 71.2% for designated toys and 88.9% for not-designated toys, respectively, showing a gradual increase from the previous reports in 2009 and 2014. On the other hand, the usages of o-acetyl tributyl citrate and adipic acid esters decreased, but the six types of PAEs prohibited to use for the designated toys in Japan were not detected in them, the usage of diisobutyl phthalate were increased. In contrast, four types of PAEs were detected in not-designated toys. Among them, the detection ratio of di (2-ethyhexyl) phthalate decreased to about 1/10. The content levels of plasticizers in per each sample were continued to keep low level from the report five years ago. These results showed that the main plasticizer used in PVC toys is DEHTP, and that the usage of other plasticizers was decreased.

[Study on Migrants Found in Migration Solutions from Commercially Available Polyethylene Products].

Migrants found in migration solutions obtained from commercially available polyethylene products that may contain food were studied and analysed via liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (LC-QTOF) for non-target screening and LC-MS/MS for quantifying 14 substances in migration solutions. Furthermore, an analytical approach based on the retention gap was developed for accurate separation techniques using LC-MS/MS. Irganox 1076 was detected at a maximum of 1.5 mg/kg, which was 1/4 of the Specific Migration Limit in the EU, in nine commercially available plastic bags tested. This is in accordance with European Regulation No 10/2011/EU. Furthermore, migration of Erucamide and Irgafos 168-oxide was confirmed.

[Modified Methods for Analyzing Bisphenol A Content for Migration Tests from Polycarbonate Food Apparatuses, Containers, and Packaging].

A validation study was performed on the modified analytical method for the migration solution of heptane, 20% ethanol and 4% acetic acid for the determination of bisphenol A migrating from polycarbonate food apparatuses, containers, and packaging. The analytes for the method were bisphenol A, phenol and p-tert-butylphenol. The repeatability, within-laboratory reproducibility and trueness of the method was estimated in the range of 0.2-1.8%, 0.4-2.6% and 95-102% respectively. These results showed that the method is useful as an analytical method for the migration solution of heptane, 20% ethanol and 4% acetic acid. Furthermore, the applicability of the determination methods with a fluorescence detector was verified. As a result of the validation study, the repeatability, within-laboratory reproducibility and trueness of the method was estimated in the range of 0.1-2.9%, 0.2-3.1% and 94-101% respectively. It was confirmed that the measurement with a fluorescence detector is also available.

Determination of potential volatile compounds in polyethylene terephthalate (PET) bottles and their short- and long-term migration into food simulants and soft drink.

Head space (HS)-GC-MS was used to analyze possible migration of volatile compounds from polyethylene terephthalate (PET) bottles for soft drinks, and a total of six compounds were identified. Next, a rapid, simple, and accurate simultaneous method was established using purge-and-trap (PT)-GC-MS, to quantify their amounts in the liquid contents after short- and long-term storage in PET bottles. Starting with brand-new PET bottles, the maximum migration of 2-methyl-1,3-dioxolane into distilled water and 50 % aqueous ethanol after 2 years at 25 °C were 2.3 and 19 ng/mL, respectively. In commercially available bottled mineral water sold inside and outside Japan, we were able to detect 2-methyl-1,3-dioxolane in the same way. While nonanal was also detected in some products, 2-methyl-1,3-dioxolane was confirmed as the main volatile compound. Finally, the human exposure to 2-methyl-1,3-dioxolane was estimated based on the per capita intake of soft drinks in Japan and the migration amount in this study.

[Validation Study on Migration Test for Plastic Food Utensils, Containers, and Packaging].

Migration test of food utensils, containers, and packaging is an important test method for confirming the safety and their compliance to the standards. However, there is little report on inter-laboratory study which was performed to evaluate the entire migration test, including migration operations and quantification. An interlaboratory study was performed participating 22 laboratories using 8 types of model synthetic resin samples containing 10 substances with a wide range of Log Pow values to evaluate the accuracy of the entire migration test. As a result, most of HorRat (r) values met the target criteria (0.3

[Inter-laboratory Study on the Modified Method Assessment for the Determining Methanol Content in Kitchen Detergents].

We modified a method for determining methanol content in detergents used in kitchens. Furthermore, an inter-laboratory study was conducted in 10 laboratories to validate the modified method. In this study, two concentrations of samples were blindly coded. Each laboratory determined the methanol content in each sample according to a protocol. The determined values were statistically analyzed according to an international harmonized guideline. HorRat values were calculated based on the reproducibility relative standard deviation (RSDR) which was estimated from the interlaboratory study, and predicted RSDR calculated from the Horwitz/Thompson equation. The HorRat values of the two samples were 0.8 and 1.8, meeting the performance criteria of less than 2 set by the Codex Alimentarius for analytical method approval. These results confirm that this modified analytical method shows good performance as an analytical method for determining methanol content in kitchen detergents.

Determination of formaldehyde and acetaldehyde levels in poly(ethylene terephthalate) (PET) bottled mineral water using a simple and rapid analytical method.

A simple and rapid analytical method was developed for the determination of formaldehyde (FA) and acetaldehyde (AA) contents in water. FA and AA were derivatized by 2,4-dinitrophenylhydrazine in an LC vial for 20 min at room temperature, about 25 °C, and analyzed using LC-MS/MS. The calibration curve exhibited excellent linearity for FA and AA concentrations of 2-150 ng/mL. Recovery tests using ultra-pure water and commercially available PET-bottled mineral water samples showed good trueness and precision. We determined the FA and AA contents in 105 PET-bottled mineral water samples on the Japanese market using this method. FA was detected in 61% of the samples at levels from 2.6 to 31.4 ng/mL, while AA was detected in 68% at levels from 5.3 to 143.5 ng/mL. These results demonstrate that the concentrations of FA and AA in PET-bottled mineral water on the Japanese market have not changed significantly over the last decade.

Rapid identification of polyamides using direct analysis in real time mass spectrometry.

RATIONALE: Polyamide (PA) is the generic name of polymers synthesized by linking monomers via amide bonds, and various types of PAs with different monomer compositions are known. Distinguishing PA polymers is useful in directing monomer residual testing, product testing, and reverse engineering, but is analytically challenging and cumbersome. To simplify this, we explored the applicability of direct analysis in real time mass spectrometry (DART-MS) for screening PA polymers. METHODS: A DART ion source coupled to a quadrupole Orbitrap (high-resolution (HR) mass spectrometer) was employed for this study. Ten types of PA polymers and four retail samples were evaluated. The DART-HRMS data for these samples, as well as the DART-MS/MS (MS2 ) data for PA6 and PA66, were obtained, and their repeatability was assessed across days/calibrations, operators, and equipments. RESULTS: Ions corresponding to the cyclic or linear monomers and oligomers of each PA polymer were detected in each DART-HR mass spectrum. Although similar DART-HR mass spectra were obtained for PA6, PA66, and PA6/PA66 (polymer blends of PA6 and PA66), their DART tandem mass spectra were completely different. The analysis was repeatable, and nearly identical DART tandem mass spectra were obtained on different days, by different operators, and with different equipment. This technique was successfully applied to commercially available samples. CONCLUSIONS: Ten types of PA polymers were distinguished using DART-HRMS and DART-MS2 , and their identification using these techniques was straightforward as the characteristic ions for each PA polymer were identified and detected. Furthermore, the spectra were obtained rapidly. Therefore, DART-HRMS can be considered an efficient screening technique for the rapid identification and differentiation of PA polymers.

[Consideration of the Evaporation Residue Test for Plastics Intended to Contact with Oils and Fatty Foods].

The Japanese Food Sanitation Act designates the evaporation residue test as a specification for plastics that intended to contact with foods. The test conditions and migration limits for oils and fatty foods were considered on the basis of the results obtained from the evaporation residue test according to the Japanese Act and the overall migration test into olive oil according to EN1186-2. The evaporation residue test was conducted using heptane at 25℃ for 1 hour. The results of most samples were under 30 µg/mL although those of high impact polystyrene,polymethylpentene and polyvinyl chloride were found to be over 30 µg/mL. However, these results were within the acceptable range of the relaxed limits (240, 120, 150 µg/mL). Regarding the overall migration into olive oil, most plastics were under the determination limit at 60℃ for 30 min. But the results for polyethylene, polypropylene and polyvinyl chloride were over 30 µg/mL at 95 and 121℃, which were higher than their evaporation residues. In other words, the existing test conditions and limits of the evaporation residue test could be used for testing plastics that come into contact with oils and fatty foods at lower temperatures. However, they are not adequate for evaluating some plastics that come into contact with oils and fatty foods at higher temperatures.

[Headspace GC/MS Analysis of Residual Solvents in Laminated Films Used for Food Packaging].

Multilayer laminated films may contain organic solvents derived from adhesives, printing inks and so on. A headspace-GC/MS analysis method for the simultaneous determination of 30 substances such as toluene, xylene, acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, methanol, ethanol, was developed. A N,N-dimethyl formamide solution containing an internal standard substance was added to the sample. After leaving overnight at room temperature, the headspace gas was analyzed by GC/MS. This method was applicable to a laminate film made of various materials. The organic solvents such as toluene, ethyl acetate, and heptane were detected from 6 out of 42 food packaging bags made from laminated film on Japanese market using this method.

[Changes in Status of Plasticizers Used in Polyvinyl Chloride Toys].

Analytical survey of plasticizers used in about 500 polyvinyl chloride (PVC) toys in Japanese market was performed in 2014. The results obtained were compared with those obtained in 2009. Fifteen types of plasticizers including di (2-ethylhexyl) terephthalate (DEHTP) were detected. These plasticizers were also detected in the products in 2009, suggesting that the types of plasticizers used in PVC toys have not been changed. Among these detected plasticizers, the detection ratios of DEHTP were 60.3 and 73.7% in both designated and not-designated toys, respectively, both of which are the highest. These ratios are over 20-points higher than those in 2009. The six types of phthalic acid esters (PAEs) prohibited to use for the designated toys in Japan were not detected in designated toys used in this study. However, four types of PAEs, including three types of prohibited PAEs, were detected in not-designated toys with the detection ratios from 2.8 to 15.5%. These ratios are lower than those in 2009. The content levels of plasticizers used in the toys are lower than those in 2009. These results show that the main plasticizer used in PVC toys is DEHTP, and that the usage levels of plasticizers have been decreased.

[Establishment of Test Methods for Overall Migration Test into Vegetable Oil Applied to Food Contact Materials Intended for Contact with Oils and Fatty Foods].

The evaporation residue test designated in the Japanese Food Sanitation Act is used to determine the total migration amount of substances that food contact materials release into foods. Vegetable oil would be the most suitable food simulant for oils and fatty foods, but it is difficult to remove by heating due to its high boiling point, so heptane and 20％ ethanol are used as substitute food simulants in the test for plastics and rubbers. The EU has introduced an overall migration test into olive oil for plastics intended to come into contact with oils and fatty foods. This test method is described in European Standard EN1186-2. However, this method has several problems. Therefore, we improved the procedures for weighing samples in a desiccator containing 43％ sulfuric acid, extraction of the absorbed vegetable oil using the soaking method with an internal standard, methyl esterification of vegetable oil using sodium methoxide, and the GC conditions for the determination of vegetable oil. The improved method is simpler and much quicker than the original method, and the harmfulness of the reagents is reduced. It can be applied to both plastics and rubbers. Comparative trials showed that the results obtained with this method and EN1186-2 method are equivalent.

[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 Evaporation Residue Test for Food Contact Products (Report 2)].

An interlaboratory study was performed to evaluate the equivalence between an official method and a modified method of evaporation residue test using heptane as a food-simulating solvent for oily or fatty foods, 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. In the official method, heating for evaporation was done with a water bath. In the modified method, a hot plate was used for evaporation, and/or a vacuum concentration procedure was skipped. In most laboratories, the test solutions were heated until just prior to dryness, and then allowed to dry under residual heat. Statistical analysis revealed that there was no significant difference between the two methods. Accordingly, the modified method provides performance equal to the official method, and is available as an alternative method. Furthermore, an interlaboratory study was performed to evaluate and compare two leaching solutions (95% ethanol and isooctane) used as food-simulating solvents for oily or fatty foods in the EU. The results demonstrated that there was no significant difference between heptane and these two leaching solutions.

Migration of nonylphenol and plasticizers from polyvinyl chloride stretch film into food simulants, rapeseed oil, and foods.

Nonylphenol (NP) has been suspected as an endocrine-disrupting chemical. Japanese polyvinyl chloride (PVC) stretch films contained 0.5-3.3 mg/g of NP and 100-400 mg/g of plasticizers such as diisononyl adipate (DINA), di-n-alkyl adipate (DAA), and diacetyllauroyl glycerol (DALG). Migration of NP and plasticizers from PVC stretch films into food simulants (water; 4% acetic acid; 20%, 50%, and 95% ethanol; and heptane), rapeseed oil, and foods was investigated. Plasticizers migrated only in small amounts into aqueous simulants and foods, although they migrated at much higher levels into 50% and 95% ethanol, heptane, rapeseed oil, and fatty foods, whereas NP more easily migrated into aqueous simulants and foods. At 5°C for 24 hr, migration of NP into vegetable and fruit was 2.9%-6.4% of their contents, and that of DINA and DAA was 0.1%-0.3%. The migration ratios of NP into aqueous foods were much higher than those of DINA and DAA. The migration ratio of NP into fatty foods, such as minced tuna and pork, was 33% and 24%, which was almost similar to that of DINA and DAA. The estimated daily intakes of NP and DINA for Japanese individuals of those days were 35 and 1,050 µg, respectively, and should not be associated with any safety concerns.

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.

Interlaboratory Study on Volatiles Test for Food-Contacting Polystyrene Products.

Using polystyrene, acrylonitrile-styrene resin and acrylonitrile-butadiene-styrene resin pellets as samples, an interlaboratory study was performed to evaluate the volatiles test method, based on the specifications described in the Japanese Food Sanitation Law for food-contacting polystyrene products. The study was conducted with the participation of twenty-one laboratories. Each laboratory quantified the contents of styrene, toluene, ethylbenzene, isopropylbenzene and propylbenzene in three test pellets using GC-FID, GC-MS or headspace-GC-FID. Statistical analysis revealed that the repeatability (RSDr) and reproducibility (RSDr) were 1.0-2.6 and 2.5-5.5% for the GC-FID method. The values of the performance parameters fulfilled the requirements (RSDr: 10%, RSDr: 25%), and the performance is sufficient for specifications testing. The RSDr and RSDr of results obtained using the GC-MS and HS-GC methods were 1.4-7.8 and 4.9-13%(GC-MS), and 2.0-2.6 and 3.3-6.9%(HS-GC-FID), respectively. The quantified levels were similar to those obtained with GC-FID. The study suggests that the GC-MS and HS-GC methods can be employed as alternative methods to the GC-FID method.

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.

Survey of Primary Aromatic Amines and Colorants in Polyurethane, Nylon and Textile Toys.

The residual and migration levels of 28 primary aromatic amines (PAAs) in polyurethane and nylon toys were determined using LC-MS/MS, and the migration and residual amounts of PAAs and 15 colorants in textile toys were determined using LC-MS/MS and LC-TOF-MS according to the European Standard EN71. Among 34 polyurethane toy samples, 2,6-diaminotoluene and 2,4-diaminotoluene were detected in the same 12 samples at residual levels ranging from 2.1 to 19.7 and from 7.6 to 39.6 µg/g, respectively. Furthermore, 4,4'-diaminodiphenylmethane (4,4'-MDA) and aniline were detected in 9 samples (from 0.2 to 8.7 µg/g), and one sample (0.4 µg/g), respectively. PAAs were not detected in the 8 samples of nylon toys. As for the migration test into water, only 4,4'-MDA migrated from 3 polyurethane toys at levels ranging from 0.4 to 2.5 µg/g. PAAs did not migrate from the 43 textile toys, but colorants such as Solvent Yellow 1 and Basic Red 9 were detected at the residual level of 0.02 µg/g. The residual levels of PAAs and colorants detected in this study were significantly lower than the limit values established by the European Union regulation.

[Interlaboratory Study on Zinc Test for Food-Contact Rubber Products].

Using six kinds of zinc solution in water and 4% acetic acid as samples, an interlaboratory study was performed to evaluate a zinc (Zn) test method for food-contact rubber products, based on the Japanese Food Sanitation Law. Eighteen laboratories participated, and quantified Zn in six test solutions as blind duplicates using flame atomic absorption spectrometry, induced coupled plasma-optical emission spectrometry or induced coupled plasma-mass spectrometry. Statistical analysis revealed that the trueness, repeatability (RSDr) and reproducibility (RSDr) were 97-103%, 0.7-4.9% and 1.7-8.9% by all measuring methods. The values of the performance parameter fulfilled the target value (trueness: 80-110%, RSDr: 10%, RSDr: 25%). The performance of these methods is sufficient for testing the adherence of samples to the specifications.