[Examination of Analytical Method for Tris(2,3-dibromopropyl)phosphate and Bis(2,3-dibromopropyl)phosphate to Revise the Official Methods Based on "Act on the Control of Household Products Containing Harmful Substances"].

In Japan, the use of frame retardants [tris(2,3-dibromopropyl)phosphate: TDBPP and bis(2,3-dibromopropyl)phosphate: BDBPP] in several household textile products is banned under the "Act on the Control of Household Products Containing Harmful Substances." As the official analytical methods for testing these substances have not been revised for over 42 years, several issues such as the using of harmful reagents, have been pointed out. Therefore, we developed a new method to revise the official method in our previous study. In this study, the validity of the developed test method is evaluated at six laboratories using two types of textile samples spiked with TDBPP and BDBPP at three concentrations (4, 8, and 20 µg/g). TDBPP and BDBPP are extracted under reflux using methanol containing hydrochloric acid. TDBPP is analyzed using GC-MS, and BDBPP is also analyzed using GC-MS after methylation with trimethylsilyl diazomethane. Although the accuracy (70-120%), repeatability (<10%), and reproducibility (<15%) of a few samples, mainly low concentration samples, are out of range, overall, the concentration level of detection limits of TDBPP and BDBPP (8 and 10 µg/g) in official analytical methods are quantifiable with sufficient precision using the proposed method. Furthermore, harmful reagents are not used in this method. Thus, the method validated in this study is effective as a revised method for the testing of TDBPP and BDBPP in household textile products.

[GC-MS Analysis of Tris(1-aziridinyl)phosphine Oxide Flame Retardants in Textile Products].

Tris(1-aziridinyl)phosphine oxide (APO) used as flame retardant in textile products, such as curtains, carpets, and sleeping clothes, is prohibited in Japan under the "Act on the Control of Household Products Containing Harmful Substances." This study developed a GC-MS-based method to quantify APO more accurately and safely than the current official method. The APO in textile products was extracted with methanol, the extract was replaced with acetone instead of hexane as previously reported, and purified by florisil cartridge column. This cleanup method was instead of the harmful and carcinogenic dichloromethane used for open column to purify the sample in the official method, giving consideration to health of analysts. For accurate and sensitive quantification, deuterated compound, APO-d12, was used as a surrogate standard. The calibration curve displayed linearity within the 0.01-2.0 µg/mL range for APO. The detection limit for APO was 0.008 µg/g with S/N=5, which was 50 times more sensitive than the current detection limit of 0.4 µg/g, enabling the analysis of sufficiently low concentrations. The recoveries in non-treatment cloth and flame-retardant textiles were 73.5-126.6% and relative standard deviations were 3.3-24.6% when 2 µg APO was added to 0.5 g of samples, confirming that it can be analyzed satisfactorily. Thus, the developed method is applicable to textile products of various materials.

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.

[Analysis of Flame Retardants Bis(2,3-dibromopropyl) phosphate and Tris(2,3-dibromopropyl) phosphate in Textile Products by GC-MS].

The use of flame retardants, namely bis(2,3-dibromopropyl) phosphate (BDBPP) and tris(2,3-dibromopropyl) phosphate (TDBPP), in textile products such as curtains, carpets and sleeping clothes is banned in Japan under the 'Act on the Control of Household Products Containing Harmful Substances'. Herein, we developed a GC-MS based method to quantify these compounds with greater accuracy and safety than the current official method. For accurate and sensitive quantification, deuterated compounds, BDBPP-d10 and TDBPP-d15, were used as surrogate standards. In consideration of the safety of the analyst, certain solvents and reagents used for the pretreatment that are carcinogenic or have a risk of explosion were replaced. For the extraction step, benzene was replaced by ethyl acetate, and for the methyl derivatization step, the reagent was changed from a self-prepared solution of diazomethane in ether to a solution of trimethylsilyl diazomethane in hexane, a safe and easy-to-use commercially available reagent. The calibration curves were liner in the range of 0.5-8.0 µg/mL for both methylated BDBPP (BDBPP-Me) and TDBPP. The detection limit was 0.05 µg/g for BDBPP-Me and 0.3 µg/g for TDBPP, which is sufficiently low compared to the current detection limits of 10 µg/g for BDBPP-Me and 8 µg/g for TDBPP. The recoveries in various curtain material were 66-108% and relative standard deviations were 1.2-10.2% when 5 µg BDBPP and TDBPP were added to 0.5 g of samples. Thus, the developed method is applicable to textile products of various materials.

[Examination of Analytical Method for Mothproofing Agents to Revise the Official Methods Based on "Act on the Control of Household Products Containing Harmful Substances"].

In Japan, the use of mothproofing agents [dieldrin and 4,6-dichloro-7-(2,4,5-trichlorophenoxy)-2-trifluoromethylbenzimidazole; DTTB] in textiles is regulated by the Act on the Control of Household Products Containing Harmful Substances. Since official analytical methods for these agents have been in place for approximately 40 years, we developed an improved method in a previous study. In the present study, we validated this method. Accordingly, six laboratories analyzed the sample prepared at 3 µg/g (1/10 of the regulation value) and 30 µg/g (the regulation value). The high accuracy of the results for these samples in almost all the cases (accuracy: 70-120%, repeatability: <10%, reproducibility: <15%), confirmed the validity of the method. In addition, we examined three samples that were distributed before the introduction of the regulation. The analysis results for these samples showed little variation between laboratiories, indicating that our method is also applicable to actual samples. Meanwhile, the quantitative value was clearly lower in one laboratory than in the others. We presumed that the enhanced effect of the sample matrix (matrix effect) on the internal standards in GC-MS analysis was the main cause for this trend. Therefore, we examined the analytical method using polyethylene glycol 300 (PEG) as an analyte protectant. As PEG minimized the GC-MS response difference between the standard solution and the matrix-containing solution, GC-MS analysis with PEG would be useful for matrix effect measurements in this method.

[Examination of Analytical Methods for Methanol, Trichloroethylene, and Tetrachloroethylene to Revise the Official Methods Based on the Act on the Control of Household Products Containing Harmful Substances].

In Japan, the use of methanol, trichloroethylene, and tetrachloroethylene in aerosol household products is banned under the Act on the Control of Household Products Containing Harmful Substances. As the official analytical methods for testing for these substances have not been revised for over 35 years, several issues have been pointed out. Thus, we developed a new method to revise the official method in our previous study. In this study, validation of the proposed method for detecting the target substances was conducted using two aerosol-product samples (A and B), which contained methanol, trichloroethylene, and tetrachloroethylene. Sample A comprised regulated values of these compounds, while sample B comprised one-tenth of the regulated amounts. They also contained several volatile compounds that served as interfering substances. Subsequently, the samples were analyzed using head space/gas chromatography-mass spectrometry, and it was confirmed that the three target substances were separated from the other chemicals on chromatograms. Validation tests were conducted at seven laboratories to evaluate the proposed method using the prepared samples. In one laboratory, the recovery of trichloroethylene and tetrachloroethylene in sample B was slightly higher at 120%, while the recoveries obtained from the other tests were between 70% and 120%. Relative standard deviation at each laboratory was less than 10%. Furthermore, the relative standard deviations between the validation tests with respect to each chemical were less than 15%. Therefore, the method validated in this study was considered to be effective as a revised method for testing for methanol, trichloroethylene, and trichloroethylene in household aerosol products.

[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.

HPLC Analysis of Colorants Migrated from Children's Modeling Clays.

A method using high-performance liquid chromatograph (HPLC) was developed for the identification of colorants migrated from colored modeling clays, which are popular toys for children. Twelve permitted dyes and 25 non-permitted dyes were analyzed in 20 clays (10 wheat clays, 2 rice clays, 2 corn clays, 3 paper clays and 3 resin clays). As a result, 13 products which were labeled for children's use (under 6 years old) met the specifications of the Japanese Food Sanitation Law, while non-permitted colorants were eluted from 2 products. In additon, unknown colorants were eluted from 3 products for people over 6 years old, although these are not covered by the Japanese regulation. It was suggested that some type of clays contained pigments, which are generally used in printing ink and plastics.

Contents of Ag and other metals in food-contact plastics with nanosilver or Ag ion and their migration into food simulants.

Six nanosilver-labelled products and five silver ion (Ag(+))-labelled products were investigated to measure the migration of Ag from food-contact plastics, including nanosilver into various food simulants. The products were obtained in Japanese markets in 2012. Zinc (Zn), another major antimicrobial agent, and three harmful metals, cadmium (Cd), lead (Pb) and arsenic (As), were also examined. Ag and Zn were detected in all six nanosilver products at concentrations of 21-200 and 8.4-140 mg kg(-1), respectively. These metals were also detected in all five Ag(+) products at the same level as nanosilver products. Cd, Pb and As were not detected in any sample. Migrations of Ag and Zn were highest in 4% acetic acid, but also observed in water and 20% ethanol. Big differences were not observed in the migration ratio between nanosilver products and Ag(+) products. The ultrafiltration experiments suggested that the Ag that migrated from nanosilver products into 4% acetic acid was in its ionic form, while that into water and 20% ethanol was in its nanoparticle form.

Development and Validation of Simultaneous Analysis of Minerals and Toxic Elements in Foods by ICP-MS.

We have developed and validated an inductively coupled plasma-mass spectrometry (ICP-MS) method for the simultaneous analysis of minerals and toxic elements in foods. Food samples were digested by microwave irradiation to prepare solutions for measurement by ICP-MS. Optimal gas mode and internal standard for each element were selected as appropriate. The method was validated for eighteen elements in total using three certified standard reference materials, namely, Typical Japanese Diet, Rice Flour-Unpolished and Infant/Adult Nutritional Formula, according to the guidelines of the Ministry of Health, Labour and Welfare of Japan. The trueness and precision of the method were all within the acceptable limits, except for Na in Rice Flour-Unpolished.

[Validation Study on Headspace-GC Analytical Method for Residual Volatile Substances in Food Contact Polystyrene and Its Application for Surveillance (1998-2014)].

A headspace-GC analysis method for the determination of residual volatile substances (styrene, toluene, ethylbenzene, isopropylbenzene and propylbenzene) in food contact polystyrene (PS) was evaluated. Ten PS products were analyzed by this headspace-GC method and the Japanese official method, and the values obtained were almost equal. The performance of the method was evaluated, and the trueness, repeatability and reproducibility were 100.4-102.8%, 3.7-6.3% and 6.0-11.1%, respectively. The values of the performance parameters of the headspace-GC method fulfilled the requirements, and this method was confirmed to be extremely precise. Moreover, contamination of the GC equipment was minimized. The residual volatile substances in 58 PS products were surveyed with this method. All products met the specifications defined in the Japanese Food Sanitation Law, and no relationship was found between volatile substances and the sampling year or country of origin.

[Determination of uranium in spinach].

After the severe accident at the Fukushima-1 Nuclear Power Plant in March 2011, radioactive contamination of food has become a matter of serious concern in Japan. There is considerable information about radioactive iodine and cesium, but little is known about uranium contamination. We determined uranium content in spinach by the Japanese official method (Manual on Radiation Measurement of Food in Emergency Situations). In the preliminary study, we confirmed that the use of a microwave digestion system for preparing the test solution of spinach could shorten the testing time and give acceptable results. The manual recommends the use of two elements (Tl and Bi) as internal standards for measurement of uranium by ICP-MS. We found that Tl was more suitable than Bi to quantify trace amounts of uranium in spinach. However, it was necessary to determine Tl or Bi concentrations in the sample before analysis, since some samples of spinach contained significant amounts of these elements. The uranium contents of 9 spinach samples bought in April and May 2011 were less than 10 µg/kg, which are very low compared to the provisional regulatory limit in Japan.

[Examination of analytical method for triphenyltin (TPT) and tributyltin (TBT) to revise the official methods based on "Act on the Control of Household Products Containing Harmful Substances"].

The use of triphenyltin (TPT) and tributyltin (TBT) in some household products is banned by "Act on the Control of Household Products Containing Harmful Substances" in Japan. To revise the official analytical method, the method for detecting these organotin compounds was examined in six laboratories using a textile product, water-based adhesive, oil-based paint, which contained known amounts of TPT and TBT (0.1, 1.0, 10 µg/g). TPT and TBT were measured by GC-MS after ethyl-derivation with sodium tetraethylborate. The TBT recoveries in the samples were 70-120%. The TPT recoveries in the water-based adhesive samples were 80-110%, while its concentrations in the textile product and oil-based paint samples decreased because of dephenylation during storage. However, the precision of the method examined was satisfactory because most coefficients of variation for TPT and TBT in the samples were less than 10%. Furthermore, the revised method was able to detect concentrations lower than the officially regulated value. However, the sample matrix and the condition of analytical instrument might affect the estimated TPT and TBT concentrations. Therefore, the revised method may not be suitable for quantitative tests; rather, it can be employed to judge the acceptable levels of these organotin compounds by comparing the values of control sample containing regulated amounts of TPT and TBT with those for an unknown sample, with deuterated TPT and TBT as surrogate substances. It is desirable that TPT in textile and oil-based paint samples are analyzed immediately after the samples obtained because of the decomposition of TPT.

[Determination of substances in polylactic acid products for food-contact use and mutagenicity of their migration solutions].

Specification tests defined in the Japanese Food Sanitation Law were conducted on 7 polylactic acid food-contact products. Moreover, the content and migration of other compounds were examined by means of ICP-AES, GC/MS and mutagenicity tests. All products met their specifications, and migration levels of heavy metals were negligible. No notable peak was observed in GC/MS analysis. Moreover, all products gave negative results in both rec-assay and the umu-test. An increase in the ß-galactosidase activity in the umu-test observed with the migration solution of soup bowl was due not to polylactic acid, but to the polyurethane coating.

[Determination of organotin compounds in water soluble paints and adhesives by GC-MS].

The use of tributyltin (TBT) and triphenyltin (TPT) in some household products are prohibited by "Act on the Control of Household Products Containing Harmful Substances" in Japan. In this study, methods for determination of TBT and TPT in water soluble paints and adhesives were developed by GC-MS. These compounds in paints and adhesives, which were mainly composed of vinyl acetate, urethane and acryl resins, and chloroprene rubber, were firstly extracted with HCl-acetone, and then extracted with hexane. On the other hand, the adhesive composed of natural rubber was firstly dispersed in water before acidification. The organotins were extracted with hexane from this solution and then these compounds were extracted with acetonitrile from hexane extract. These extracts were purified by a florisil cartridge column after ethyl-derivation with sodium tetraethylborate, and analyzed by GC-MS. The quantifications using deuterated compound of both organotins as surrogate standard were conducted, and good results were obtained. The recoveries were 81 to 118% and the coefficients of variation were 0.83 to 4.3% (TBT and TPT added; 5 microg/g). The method quantification limits were 0.0090 to 0.025 microg/g, which were lower than those of an official method. These methods were applied to monobutyltin (MBT), dibutyltin (DBT), monophenyltin (MPT), and diphenyltin (DPT). DBT and DPT in paints and adhesives were quantified, except for DPT in natural rubber. These methods were applied to commercial products. DBT was detected at low concentrations (t.r.-0.19 microg/g) in some paint samples, while TBT and TPT were not detected in all samples.

Migration of dehydroabietic and abietic acids from paper and paperboard food packaging into food-simulating solvents and Tenax TA.

An investigation was undertaken to establish the concentration in paper products of dehydroabietic (DHA) and abietic (AA) resin acids, present in rosin, which are major toxicants of pulp- and paper-mill effluent. Their migration was studied from paper and paperboard products into various food-simulating solvents and the substitute fatty food simulant Tenax TA (modified polyphenylene oxide). DHA and AA were detected in five of 10 virgin paper products and in all 10 recycled paperboard products for food-contact use at concentrations of 14-500 and 110-1200 microg/g, respectively. In virgin paper products, the highest migration was into 95% ethanol or heptane, with negligible or no migration into other solvents. In recycled paperboard products, migration was highest into 95% ethanol, but was also observed into 20% ethanol, water and heptane. Migration to Tenax TA was also observed and the migration level increased with time. The maximum migration levels of DHA and AA into food simulants were 0.853 and 3.14 microg/g, respectively. The results suggest that, in the worst case, the daily intake of DHA and AA from paper and paperboard products was 50 times lower than the tolerable daily intake of rosin.