Maiko Tahara - Academia.edu (original) (raw)
Papers by Maiko Tahara
Yakugaku zasshi, Apr 1, 2024
In Japan, the use of frame retardants [tris(2,3-dibromopropyl)phosphate: TDBPP and bis(2,3-dibrom... more 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.
BPB reports, 2024
The Ministry of Health, Labour and Welfare of Japan has set the guideline values for indoor air c... more The Ministry of Health, Labour and Welfare of Japan has set the guideline values for indoor air concentrations of 13 volatile organic compounds (VOCs) and semi-volatile organic compounds from 1997 to 2002. However, in 2019, the guideline values for three of these substances, including xylene, were revised and regulated more strictly. Additionally, the manual for analysis of VOCs in indoor air, established in 2001 by the Committee on Sick House Syndrome: Indoor Air Pollution, has not been updated for over 20 years. In this study, we confirmed that the current analytical method for VOCs in indoor air using solvent extraction which was established in 2001, is applicable to VOCs that have been revised or added since then. We proposed it as a standard test method and performed an inter-laboratory validation study in five laboratories to prove this. This validation study included nine substances: six VOCs with current guideline values and three VOCs as candidates for newly setting guideline values. Additional amount in this study was set as 1 µg, less than one-tenth of the guideline value for xylene. The results showed that the average recovery, repeatability, and reproducibility for the nine substances in the five laboratories were 75.4%-115%, 0.78%-9.6%, and 3.6%-21%, respectively. These values satisfied the determined criteria ranges, suggesting that our proposed analytical method can be used as a standard test method.
The confirmation ion for fenobucarb was m/z 150. Therefore, Table 2 needs to be corrected.
The Pharmaceutical Society of Japan, Feb 1, 2021
Applications of NMR Spectroscopy, 2016
BPB reports, 2021
Volatile organic compounds (VOCs) emitted from indoor household items are known to contribute to ... more Volatile organic compounds (VOCs) emitted from indoor household items are known to contribute to health problems, such as sick building syndrome, in occupants of residential spaces. The negative health effects of VOCs exposure have promoted interest in understanding and improving indoor air quality. However, there is limited information on the indoor air pollution caused by household items introduced by residents, in particular bedding items, which will be present for a long time in the resident's breathing zone. Therefore, to minimize the health effects of indoor air pollution, it is important to identify the chemical substances emitted from these household items. Although there have been studies measuring VOC emissions from mattresses using the chamber method, 1,2) to the best of our knowledge, there are no published studies using the sampling bag method. For this study, we obtained a sample of pillows and mattresses that had been marketed and distributed in Japan. VOCs emitted from the bedding items were collected using the sampling bag method, and were quantified using thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS). Aldehydes, one of the group of VOCs, were quantified using high-performance liquid chromatography (HPLC). MATERIALS AND METHODS Chemicals The target substances for analysis for every group are listed in Table 1. 48 Component Indoor Air Standard and TO11/IP-6A Aldehyde/Ketone-DNPH Mix were purchased from Supelco, Inc. 2-Ethyl-1-hexanol (98%) was purchased from Wako Pure Chemical Industries, Ltd. 3-Hydroxy-2,2,4-trimethylpentyl isobutyrate (Texanol; contains ca. 40% 2,2,4-trimethyl-1,3-pentanediol 3-monoisobutyrate) and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TXIB; > 97.0%) were purchased from Tokyo Chemical Industry Co., Ltd. Toluene-d 8 , purchased from Wako Pure Chemical Industries, Ltd., was used as an internal standard in the GC/MS analysis in this study. Instruments TD-GC/MS analysis was performed using a TD-100xr (MARKES International Ltd.) equipped with Agilent 7890B/5977B GC/MSD series (Agilent Technologies, Inc.). MP-Σ30 NII sampling pumps (Sibata Scientific Technology Ltd.) was used for collection of VOCs except that MP-Σ300 NII sampling pumps (Sibata Scientific Technology Ltd.) was for aldehyde group. The sampling bag method was conducted using Skypia ® bags (GL Sciences Inc.). Tenax ® TA 60/80 (Camsco Co.) collection tubes were used for VOCs whereas InertSep ® mini AERO DNPH (GL Sciences Inc.) collection tubes was for aldehyde group. Product Samples We purchased 20 pillows and 20 mattresses from Japanese domestic internet markets. The pillows were composed of the following materials: polyester (P-1-P-7) in 7, urethane foam (P-8-P-14) in 7, polyethylene (pipe) (P-15-P-18) in 4, and buckwheat hull (P-19, P-20) in 2. All 20 mattresses were composed of urethane foam (M-1-M-20). Emissions Tests As recommended by the Japanese Automotive Standards Organization M902 (JASO M902), 2018 edition, 3) the sampling bag method was used to collect emitted chemical substances. For each test, one item of bedding was properly stored at room temperature until it was opened. Immediately after opening the package, we sealed in a sampling bag
Environmental Sciences, Sep 28, 2012
PubMed, 2009
Wide application of fullerenes in various areas would increase the risk of occupational and envir... more Wide application of fullerenes in various areas would increase the risk of occupational and environmental exposure to human. However, information about toxicity and biological behavior of fullerenes is not sufficient for the risk assessment at present. For the determination of fullerene C60 in biological samples, an analytical method using high performance liquid chromatography--tandem mass spectrometry (LC-MS/MS) and extraction procedure from tissues of experimental animals was established in this study. Using LC-MS/MS with an atmospheric pressure chemical ionization in negative mode, C60 were identified and quantified. After optimization of mobile phase and separation column, good separation of peak of fullerene and sensitivity were obtained in case of using toluene and acetonitrile as the mobile phases and Develosil RPFULLERENE as the separation column. For method validation, rat brain, kidney, liver, lung, spleen tissues and blood were used for recovery tests. Good results were obtained and the recovery percentages were found to be between 98.1% and 106.5%.
Journal of Health Science, 2006
We established a method for the simultaneous quantitative analysis of nine organophosphorus pesti... more We established a method for the simultaneous quantitative analysis of nine organophosphorus pesticides (OPs) and their active oxon forms in water samples using gas chromatography with mass spectrometric detection with solid-phase extraction (SPE). In this method, the lower limit of detection for the nine oxons ranged from 0.5 to 20 ng/ml. Each calibration curve had good linearity, with correlation coefficients (R 2) greater than 0.991. In comparing three SPE cartridges, the recovery rate of these compounds extracted from water was highly reproducible using a cartridge of packed silica bonded with C 18. The limit of quantification ranged from 2.5 to 200 ng/ml at 500-fold concentrations. When the OPs were examined after chlorination treatment to simulate the water treatment process, they decomposed rapidly and were converted to their oxon forms as primary reaction products of chlorination. Under these established analytical conditions, the behavior of oxons formed in the environment and after water treatment can be determined accurately.
Toxicology Letters, Aug 1, 2011
To study the potential of NPs to provoke oxidative stress (i) various mutant microbial strains vu... more To study the potential of NPs to provoke oxidative stress (i) various mutant microbial strains vulnerable to reactive oxygen species (ROS) and (ii) ROS-sensing recombinant luminescent bacteria were used. To analyse the solubilisation of metallic NPs, recombinant luminescent metal sensing bacteria and chemical methods were used in parallel. For NP characterization, specific surface area, hydrodynamic size and z-potential were measured. Results: We showed that silver NPs were up to 1000-fold more toxic than CuO NPs. Toxicity depended on agglomeration of NPs, test organism and was modulated by environmental factors (e.g., temperature, salinity, pH, test medium). The combined approach using classical ecotoxicological test methods, phyico-chemical characterization of NPs and recombinant microbial sensors is a versatile tool for (eco) toxicological and mechanistic profiling of synthetic NPs.
Toxicology Letters, Oct 1, 2008
Inflammation was determined by expression of CD11b upon stimulation with particles. Complement ac... more Inflammation was determined by expression of CD11b upon stimulation with particles. Complement activation was determined by C3a and C5a generation in our biological samples. Also this analysis showed that C3a and C5a generation only depended on the positive charge of the particles and not on their sizes. With our study we pointed out that size and surface charge of nanoparticles influence the investigated parameters in a complex manner, especially the surface charge affects coagulation and complement activation but not hemolysis.
Journal of Liquid Chromatography & Related Technologies, Jul 21, 2021
Abstract Isothiazolinone preservatives are known to cause contact dermatitis. Although they are u... more Abstract Isothiazolinone preservatives are known to cause contact dermatitis. Although they are used in household deodorizers and air fresheners, the actual extent of their use remains unclear. In this study, we developed a method to simultaneously analyze five isothiazolinones (2-methyl-4-isothiazilin-3-one: MI, 5-choro-2-methyl-4-isothiazolin-3-one: CMI, benzisothiazolin-3-one: BIT, 2-n-octyl-4-isothiazolin-3-one: OIT, 4,5-dichloro-n-octyl-4-isothiazolin-3-one: 2Cl-OIT) in spray-type household deodorizers and air fresheners. The samples were analyzed through solid-phase extraction and liquid chromatography–tandem mass spectrometry. Three solid-phase extraction cartridges were examined, and good results were obtained for the OASIS HLB Plus LP cartridge. The recoveries and standard deviations for isothiazolinone preservatives extracted using this cartridge were 72–99 and 1.6–6.0%, respectively. In addition, the limit of detection and limit of quantification were as follow: 0.012 and 0.037 μg/mL for MI, 0.029 and 0.089 μg/mL for CMI, 0.032 and 0.098 μg/mL for BIT, 0.013 and 0.040 μg/mL for OIT, and 0.015 and 0.047 μg/mL for 2Cl-OIT. Among the 51 analyzed products, only 10 were detected with isothiazolinone compounds. MI and CMI were detected in five products at concentration levels of 0.31–22 and 0.77–95 μg/mL, respectively, while BIT was detected in the other five products at 2.7–101 μg/mL. Graphical Abstract
Journal of AOAC International, Mar 1, 2020
Background: The static headspace technique is one of the most popular techniques for residual sol... more Background: The static headspace technique is one of the most popular techniques for residual solvent analysis and dimethyl sulfoxide (DMSO) and N,N-dimethylformamide (DMF) are widely use as the dissolution media. Objective: This study aims to establish ethyl lactate (EL), a solvent with low toxicity and less environmental impact, as an alternative dissolution medium to DMSO and DMF for the static headspace analysis of toxic residual solvents in food, cosmetics, and similar complex organic matrices. Methods: Samples (a sample of dietary supplement and two samples each of cosmetics and household products) spiked with benzene, carbon tetrachloride, 1,2-dichloroethane, 1,1-dichloroethene, and 1,1,1-trichloroethane were dissolved in EL, DMSO, and DMF. Static headspace GC/MS and the standard addition method were used to detect and quantify the residual solvents. Results: The dissolution and dispersion of these samples, especially the ones which were waterinsoluble, were better than those in DMSO and DMF. The recoveries, except that of benzene in an aerosol spray, in EL ranged from 77 to 110%. The relative SDs in EL ranged from 2.5 to 11% and were better or equivalent to those in DMSO and DMF. Conclusions: EL was suitable as the dissolution medium for such samples, which may contain large amounts of organic solvents or various ingredients, in static headspace GC/MS analysis of residual solvents. O rganic solvents are important in the synthesis and production of food, cosmetics, household products, consumer products, drugs, etc. Many organic solvents used for these purposes are toxic or environmentally hazardous. Therefore, efforts have been taken to control the use of some of these solvents in the production of food, cosmetics, drugs, household products, and consumer products (1-4). In an attempt toward SPECIAL GUEST EDITOR SECTION
Journal of Water and Environment Technology, 2010
Japan's recommended method of EDTA determination is complex and time-consuming. In this study, a ... more Japan's recommended method of EDTA determination is complex and time-consuming. In this study, a new method to prepare the solution to determine EDTA in water by solid-phase extraction-GC/MS was developed. Recovery yields were excellent with values ranging from 98.1 to 100.5%. Due to this method's ease and simplicity, it is suggested that this approach be adopted as Japan's recommended method for EDTA analysis. The method was applied to assess the concentrations of EDTA in river water from three regions of Japan. Median concentration of EDTA in river water samples was 115 μg/L, and the concentrations ranged from 18.8 to 443 μg/L. The highest concentration of EDTA (443 μg/L) was observed in Tsurumi River. Sewage treatment plant (STP) effluent significantly contributed to high EDTA levels.
Kankyō kagaku, 2022
This article is licensed under a Creative Commons [Attribution-NonCommercial-NoDerivatives. Inter... more This article is licensed under a Creative Commons [Attribution-NonCommercial-NoDerivatives. International] license.
International Journal of Cosmetic Science, Aug 5, 2013
1,4-Dioxane is a toxic by-product formed during the synthesis of surfactants used in finished cos... more 1,4-Dioxane is a toxic by-product formed during the synthesis of surfactants used in finished cosmetic products. There are no set permissible levels of toxic impurities in finished cosmetic products in Japan. In this study, we have established a simple and sufficiently precise analytical method to determine the activity of 1,4-dioxane in finished cosmetic cleansing products. This method involves the standard addition approach and headspace-gas chromatography/mass spectrometry without pre-conditioning. Fifteen cleansing products that are sold in the Japanese market, such as shampoo, hand soap, and dishwashing liquid, were analyzed, and 1,4-dioxane was detected at a concentration of a few micrograms per gram of the product in almost all of them. The concentration of 1,4-dioxane in two dishwashing liquid products was high. The maximum concentration of 1,4-dioxane in all of the cleansing products was below 10 μg g(-1) , which is a limit that is thought to be safe and technically achievable through the application of good manufacturing practices. Since 1,4-dioxane is formed during the synthesis of polyoxyethylene ether sulfate, it was detected at high concentrations in cleansing products that contained a lot of polyoxyethylene ether sulfate. Control of the synthesis of polyoxyethylene ether sulfate can be effective in reducing the concentration of 1,4-dioxane in cleansing products.
Yakugaku zasshi, Apr 1, 2024
In Japan, the use of frame retardants [tris(2,3-dibromopropyl)phosphate: TDBPP and bis(2,3-dibrom... more 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.
BPB reports, 2024
The Ministry of Health, Labour and Welfare of Japan has set the guideline values for indoor air c... more The Ministry of Health, Labour and Welfare of Japan has set the guideline values for indoor air concentrations of 13 volatile organic compounds (VOCs) and semi-volatile organic compounds from 1997 to 2002. However, in 2019, the guideline values for three of these substances, including xylene, were revised and regulated more strictly. Additionally, the manual for analysis of VOCs in indoor air, established in 2001 by the Committee on Sick House Syndrome: Indoor Air Pollution, has not been updated for over 20 years. In this study, we confirmed that the current analytical method for VOCs in indoor air using solvent extraction which was established in 2001, is applicable to VOCs that have been revised or added since then. We proposed it as a standard test method and performed an inter-laboratory validation study in five laboratories to prove this. This validation study included nine substances: six VOCs with current guideline values and three VOCs as candidates for newly setting guideline values. Additional amount in this study was set as 1 µg, less than one-tenth of the guideline value for xylene. The results showed that the average recovery, repeatability, and reproducibility for the nine substances in the five laboratories were 75.4%-115%, 0.78%-9.6%, and 3.6%-21%, respectively. These values satisfied the determined criteria ranges, suggesting that our proposed analytical method can be used as a standard test method.
The confirmation ion for fenobucarb was m/z 150. Therefore, Table 2 needs to be corrected.
The Pharmaceutical Society of Japan, Feb 1, 2021
Applications of NMR Spectroscopy, 2016
BPB reports, 2021
Volatile organic compounds (VOCs) emitted from indoor household items are known to contribute to ... more Volatile organic compounds (VOCs) emitted from indoor household items are known to contribute to health problems, such as sick building syndrome, in occupants of residential spaces. The negative health effects of VOCs exposure have promoted interest in understanding and improving indoor air quality. However, there is limited information on the indoor air pollution caused by household items introduced by residents, in particular bedding items, which will be present for a long time in the resident's breathing zone. Therefore, to minimize the health effects of indoor air pollution, it is important to identify the chemical substances emitted from these household items. Although there have been studies measuring VOC emissions from mattresses using the chamber method, 1,2) to the best of our knowledge, there are no published studies using the sampling bag method. For this study, we obtained a sample of pillows and mattresses that had been marketed and distributed in Japan. VOCs emitted from the bedding items were collected using the sampling bag method, and were quantified using thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS). Aldehydes, one of the group of VOCs, were quantified using high-performance liquid chromatography (HPLC). MATERIALS AND METHODS Chemicals The target substances for analysis for every group are listed in Table 1. 48 Component Indoor Air Standard and TO11/IP-6A Aldehyde/Ketone-DNPH Mix were purchased from Supelco, Inc. 2-Ethyl-1-hexanol (98%) was purchased from Wako Pure Chemical Industries, Ltd. 3-Hydroxy-2,2,4-trimethylpentyl isobutyrate (Texanol; contains ca. 40% 2,2,4-trimethyl-1,3-pentanediol 3-monoisobutyrate) and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TXIB; > 97.0%) were purchased from Tokyo Chemical Industry Co., Ltd. Toluene-d 8 , purchased from Wako Pure Chemical Industries, Ltd., was used as an internal standard in the GC/MS analysis in this study. Instruments TD-GC/MS analysis was performed using a TD-100xr (MARKES International Ltd.) equipped with Agilent 7890B/5977B GC/MSD series (Agilent Technologies, Inc.). MP-Σ30 NII sampling pumps (Sibata Scientific Technology Ltd.) was used for collection of VOCs except that MP-Σ300 NII sampling pumps (Sibata Scientific Technology Ltd.) was for aldehyde group. The sampling bag method was conducted using Skypia ® bags (GL Sciences Inc.). Tenax ® TA 60/80 (Camsco Co.) collection tubes were used for VOCs whereas InertSep ® mini AERO DNPH (GL Sciences Inc.) collection tubes was for aldehyde group. Product Samples We purchased 20 pillows and 20 mattresses from Japanese domestic internet markets. The pillows were composed of the following materials: polyester (P-1-P-7) in 7, urethane foam (P-8-P-14) in 7, polyethylene (pipe) (P-15-P-18) in 4, and buckwheat hull (P-19, P-20) in 2. All 20 mattresses were composed of urethane foam (M-1-M-20). Emissions Tests As recommended by the Japanese Automotive Standards Organization M902 (JASO M902), 2018 edition, 3) the sampling bag method was used to collect emitted chemical substances. For each test, one item of bedding was properly stored at room temperature until it was opened. Immediately after opening the package, we sealed in a sampling bag
Environmental Sciences, Sep 28, 2012
PubMed, 2009
Wide application of fullerenes in various areas would increase the risk of occupational and envir... more Wide application of fullerenes in various areas would increase the risk of occupational and environmental exposure to human. However, information about toxicity and biological behavior of fullerenes is not sufficient for the risk assessment at present. For the determination of fullerene C60 in biological samples, an analytical method using high performance liquid chromatography--tandem mass spectrometry (LC-MS/MS) and extraction procedure from tissues of experimental animals was established in this study. Using LC-MS/MS with an atmospheric pressure chemical ionization in negative mode, C60 were identified and quantified. After optimization of mobile phase and separation column, good separation of peak of fullerene and sensitivity were obtained in case of using toluene and acetonitrile as the mobile phases and Develosil RPFULLERENE as the separation column. For method validation, rat brain, kidney, liver, lung, spleen tissues and blood were used for recovery tests. Good results were obtained and the recovery percentages were found to be between 98.1% and 106.5%.
Journal of Health Science, 2006
We established a method for the simultaneous quantitative analysis of nine organophosphorus pesti... more We established a method for the simultaneous quantitative analysis of nine organophosphorus pesticides (OPs) and their active oxon forms in water samples using gas chromatography with mass spectrometric detection with solid-phase extraction (SPE). In this method, the lower limit of detection for the nine oxons ranged from 0.5 to 20 ng/ml. Each calibration curve had good linearity, with correlation coefficients (R 2) greater than 0.991. In comparing three SPE cartridges, the recovery rate of these compounds extracted from water was highly reproducible using a cartridge of packed silica bonded with C 18. The limit of quantification ranged from 2.5 to 200 ng/ml at 500-fold concentrations. When the OPs were examined after chlorination treatment to simulate the water treatment process, they decomposed rapidly and were converted to their oxon forms as primary reaction products of chlorination. Under these established analytical conditions, the behavior of oxons formed in the environment and after water treatment can be determined accurately.
Toxicology Letters, Aug 1, 2011
To study the potential of NPs to provoke oxidative stress (i) various mutant microbial strains vu... more To study the potential of NPs to provoke oxidative stress (i) various mutant microbial strains vulnerable to reactive oxygen species (ROS) and (ii) ROS-sensing recombinant luminescent bacteria were used. To analyse the solubilisation of metallic NPs, recombinant luminescent metal sensing bacteria and chemical methods were used in parallel. For NP characterization, specific surface area, hydrodynamic size and z-potential were measured. Results: We showed that silver NPs were up to 1000-fold more toxic than CuO NPs. Toxicity depended on agglomeration of NPs, test organism and was modulated by environmental factors (e.g., temperature, salinity, pH, test medium). The combined approach using classical ecotoxicological test methods, phyico-chemical characterization of NPs and recombinant microbial sensors is a versatile tool for (eco) toxicological and mechanistic profiling of synthetic NPs.
Toxicology Letters, Oct 1, 2008
Inflammation was determined by expression of CD11b upon stimulation with particles. Complement ac... more Inflammation was determined by expression of CD11b upon stimulation with particles. Complement activation was determined by C3a and C5a generation in our biological samples. Also this analysis showed that C3a and C5a generation only depended on the positive charge of the particles and not on their sizes. With our study we pointed out that size and surface charge of nanoparticles influence the investigated parameters in a complex manner, especially the surface charge affects coagulation and complement activation but not hemolysis.
Journal of Liquid Chromatography & Related Technologies, Jul 21, 2021
Abstract Isothiazolinone preservatives are known to cause contact dermatitis. Although they are u... more Abstract Isothiazolinone preservatives are known to cause contact dermatitis. Although they are used in household deodorizers and air fresheners, the actual extent of their use remains unclear. In this study, we developed a method to simultaneously analyze five isothiazolinones (2-methyl-4-isothiazilin-3-one: MI, 5-choro-2-methyl-4-isothiazolin-3-one: CMI, benzisothiazolin-3-one: BIT, 2-n-octyl-4-isothiazolin-3-one: OIT, 4,5-dichloro-n-octyl-4-isothiazolin-3-one: 2Cl-OIT) in spray-type household deodorizers and air fresheners. The samples were analyzed through solid-phase extraction and liquid chromatography–tandem mass spectrometry. Three solid-phase extraction cartridges were examined, and good results were obtained for the OASIS HLB Plus LP cartridge. The recoveries and standard deviations for isothiazolinone preservatives extracted using this cartridge were 72–99 and 1.6–6.0%, respectively. In addition, the limit of detection and limit of quantification were as follow: 0.012 and 0.037 μg/mL for MI, 0.029 and 0.089 μg/mL for CMI, 0.032 and 0.098 μg/mL for BIT, 0.013 and 0.040 μg/mL for OIT, and 0.015 and 0.047 μg/mL for 2Cl-OIT. Among the 51 analyzed products, only 10 were detected with isothiazolinone compounds. MI and CMI were detected in five products at concentration levels of 0.31–22 and 0.77–95 μg/mL, respectively, while BIT was detected in the other five products at 2.7–101 μg/mL. Graphical Abstract
Journal of AOAC International, Mar 1, 2020
Background: The static headspace technique is one of the most popular techniques for residual sol... more Background: The static headspace technique is one of the most popular techniques for residual solvent analysis and dimethyl sulfoxide (DMSO) and N,N-dimethylformamide (DMF) are widely use as the dissolution media. Objective: This study aims to establish ethyl lactate (EL), a solvent with low toxicity and less environmental impact, as an alternative dissolution medium to DMSO and DMF for the static headspace analysis of toxic residual solvents in food, cosmetics, and similar complex organic matrices. Methods: Samples (a sample of dietary supplement and two samples each of cosmetics and household products) spiked with benzene, carbon tetrachloride, 1,2-dichloroethane, 1,1-dichloroethene, and 1,1,1-trichloroethane were dissolved in EL, DMSO, and DMF. Static headspace GC/MS and the standard addition method were used to detect and quantify the residual solvents. Results: The dissolution and dispersion of these samples, especially the ones which were waterinsoluble, were better than those in DMSO and DMF. The recoveries, except that of benzene in an aerosol spray, in EL ranged from 77 to 110%. The relative SDs in EL ranged from 2.5 to 11% and were better or equivalent to those in DMSO and DMF. Conclusions: EL was suitable as the dissolution medium for such samples, which may contain large amounts of organic solvents or various ingredients, in static headspace GC/MS analysis of residual solvents. O rganic solvents are important in the synthesis and production of food, cosmetics, household products, consumer products, drugs, etc. Many organic solvents used for these purposes are toxic or environmentally hazardous. Therefore, efforts have been taken to control the use of some of these solvents in the production of food, cosmetics, drugs, household products, and consumer products (1-4). In an attempt toward SPECIAL GUEST EDITOR SECTION
Journal of Water and Environment Technology, 2010
Japan's recommended method of EDTA determination is complex and time-consuming. In this study, a ... more Japan's recommended method of EDTA determination is complex and time-consuming. In this study, a new method to prepare the solution to determine EDTA in water by solid-phase extraction-GC/MS was developed. Recovery yields were excellent with values ranging from 98.1 to 100.5%. Due to this method's ease and simplicity, it is suggested that this approach be adopted as Japan's recommended method for EDTA analysis. The method was applied to assess the concentrations of EDTA in river water from three regions of Japan. Median concentration of EDTA in river water samples was 115 μg/L, and the concentrations ranged from 18.8 to 443 μg/L. The highest concentration of EDTA (443 μg/L) was observed in Tsurumi River. Sewage treatment plant (STP) effluent significantly contributed to high EDTA levels.
Kankyō kagaku, 2022
This article is licensed under a Creative Commons [Attribution-NonCommercial-NoDerivatives. Inter... more This article is licensed under a Creative Commons [Attribution-NonCommercial-NoDerivatives. International] license.
International Journal of Cosmetic Science, Aug 5, 2013
1,4-Dioxane is a toxic by-product formed during the synthesis of surfactants used in finished cos... more 1,4-Dioxane is a toxic by-product formed during the synthesis of surfactants used in finished cosmetic products. There are no set permissible levels of toxic impurities in finished cosmetic products in Japan. In this study, we have established a simple and sufficiently precise analytical method to determine the activity of 1,4-dioxane in finished cosmetic cleansing products. This method involves the standard addition approach and headspace-gas chromatography/mass spectrometry without pre-conditioning. Fifteen cleansing products that are sold in the Japanese market, such as shampoo, hand soap, and dishwashing liquid, were analyzed, and 1,4-dioxane was detected at a concentration of a few micrograms per gram of the product in almost all of them. The concentration of 1,4-dioxane in two dishwashing liquid products was high. The maximum concentration of 1,4-dioxane in all of the cleansing products was below 10 μg g(-1) , which is a limit that is thought to be safe and technically achievable through the application of good manufacturing practices. Since 1,4-dioxane is formed during the synthesis of polyoxyethylene ether sulfate, it was detected at high concentrations in cleansing products that contained a lot of polyoxyethylene ether sulfate. Control of the synthesis of polyoxyethylene ether sulfate can be effective in reducing the concentration of 1,4-dioxane in cleansing products.