Novel automated identification and quantification database using liquid chromatography quadrupole time-of-flight mass spectrometry for quick, comprehensive, cheap and extendable organic micro-pollutant analysis in environmental systems.

In order to protect human health and the environment, highly efficient, low-cost, labor-saving, and green analysis of toxic chemicals are urgently required. To achieve this objective, we have developed a novel database-based automated identification and quantification system (AIQS) using LC-QTOF-MS. Since the AIQS uses retention times (RTs), exact MS and MS-MS spectra, and calibration curves of 484 chemicals registered in the database instead of the use of standards, the targets can be determined with low-cost in a short time. The AIQS uses Sequential Window Acquisition of All Theoretical Fragment-ion Spectra as an acquisition method by which we can obtain accurate MS and MS-MS spectra of all detectable substances in a sample with minimal interference from co-eluted peaks. Identification is certainly done using RTs, mass error, ion ratios (a precursor to two product ions), and accurate MS and MS-MS spectra. Consequently, the chance of misidentification is very low even in dirty samples. To examine the accuracy of the AIQS, two collaborative tests were conducted. The first test used 208 pesticide standards at two concentrations (10 and 100 ng mL-1) using 7 instruments, and showed that average trueness was 106 and 95.2%, respectively, with relative standard deviations of 90% of the test compounds below 30%. The second collaborative study involved 5 laboratories carrying out recovery tests on 200 pesticides using 10 river waters. The average recovery was 71.6%; this was 15% lower than that using purified water probably due to the matrix effects. The average relative standard deviation was 30% worse than that of measurement of the standards. Both the recovery and reproducibility, however, satisfied the criteria of Analytical Method Validity Guidelines, Ministry of Health, Labour and Welfare, Japan. Instrument detection limits of 96% of the registered compounds are below 10 pg. The AIQS allows for easy addition of new substances and retrospective analysis after their addition. The results applied to actual samples showed that the AIQS has sufficient identification and quantification performance as a target screening method for a large number of substances in environmental samples.

Benzotriazole ultraviolet stabilizers show potent activities as human aryl hydrocarbon receptor ligands.

Benzotriazole ultraviolet stabilizers (BUVSs) used in consumer products are raising concerns as new pollutants in the aquatic environment. We determined the agonistic activities of eight BUVSs and a chemically distinct UV absorber (4-methylbenzylidinecamphor) toward the human aryl hydrocarbon receptor (AhR) and thyroid hormone receptors alpha and beta. Although none of the BUVSs showed ligand activity against the thyroid hormone receptors, four of them (UV-P, UV-9, UV-326, and UV-090) showed significant AhR ligand activity. Their half-maximal effective concentrations (EC50) were 130 nM for UV-P, 460 nM for UV-9, and 5.1 µM for UV-090 (a value for UV-326 could not be determined). Of the numerous AhR ligands, it is well-known that those considered nontoxic are quickly metabolized by enzymes such as CYP1A1, which destroys their ability to function as ligands. Accordingly, we established a new yeast assay for simultaneous monitoring of both the strength of AhR ligand activity and ligand degradation by CYP1A1. We found the AhR ligand activities of the above four BUVSs to be stable in the presence of CYP1A1; therefore, they have the potential to accumulate and exert potent physiological effects in humans, analogous to polycyclic aromatic hydrocarbons and dioxins, which are known stable and toxic ligands.

Inhalation and dietary exposure to Dechlorane Plus and polybrominated diphenyl ethers in Osaka, Japan.

This study estimated daily exposure to Dechlorane Plus (DP) and polybrominated diphenyl ethers (PBDE) via inhalation and diet. Samples of atmospheric particles and food (obtained by market basket method) from Osaka, Japan were analyzed for DP (syn-, anti-) and PBDE using gas chromatography-mass spectrometry. DP was detected in both atmospheric particles and food samples. Among the atmospheric particles, DP was detected in all samples. ΣDP concentration was 7.1-15.4 pg m(-3) and anti-DP was the dominant residue among DP isomers. PBDE was also detected in all the atmospheric particles. ΣPBDE concentration was 9.9-23.3 pg m(-3). In the market basket study, DP was detected in Groups Ш (sugar and confectionary), V (legumes and their products), X (fish, shellfish, and their products), and XI (meat and eggs) at concentrations of 3.3, 2.8, 1.9, and 1.5 pg g(-1) wet wt, respectively. PBDE was detected in Groups Ш, IV (oils and fats), V, X, XI, and XШ (seasonings and other processed foods) at concentrations of 153, 79.1, 74.6, 308, 94.8, and 186 pg g(-1) wet wt, respectively. The daily intake of ΣDP (750 pg day(-1)) via inhalation and diet was approximately one percent of that for ΣPBDE (62 ng day(-1)).

Fate of perfluorooctanesulfonate and perfluorooctanoate in drinking water treatment processes.

Perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) have been recognized as global environmental pollutants. Although PFOS and PFOA have been detected in tap water from Japan and several other countries, very few studies have examined the fate, especially removal, of perfluorinated compounds (PFCs) in drinking water treatment processes. In this study, we analyzed PFOS and PFOA at every stages of drinking water treatment processes in several water purification plants that employ advanced water treatment technologies. PFOS and PFOA concentrations did not vary considerably in raw water, sand filtered water, settled water, and ozonated water. Sand filtration and ozonation did not have an effect on the removal of PFOS and PFOA in drinking water. PFOS and PFOA were removed effectively by activated carbon that had been used for less than one year. However, activated carbon that had been used for a longer period of time (>1 year) was not effective in removing PFOS and PFOA from water. Variations in the removal ratios of PFOS and PFOA by activated carbon were found between summer and winter months.

Perfluorooctanesulfonate and perfluorooctanoate in raw and treated tap water from Osaka, Japan.

Perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) have been recognized as emerging environmental pollutants because of their ubiquitous occurrence in the environment, biota, and humans. PFOS and PFOA have been detected in water in Japan. Nevertheless, occurrence of PFOS and PFOA in potable water from municipal water treatment plants is not clearly known. We analyzed PFOS and PFOA in raw and tap water samples collected from 14 drinking water treatment plants in winter and summer seasons in Osaka to determine the concentrations of PFOS and PFOA in raw and potable tap water samples. PFOS and PFOA were detected in all raw water samples. Concentration ranges of PFOS and PFOA in raw water were 0.26-22 ng/l and 5.2-92 ng/l, respectively. Whereas the concentrations PFOS in raw water from Osaka were similar to those in other areas in Japan, the concentrations of PFOA were higher than in other areas. Concentration ranges of PFOS and PFOA in potable tap water were 0.16-22 ng/l and 2.3-84 ng/l, respectively. There were positive correlations between PFC concentrations in raw water and tap water samples. Therefore, the removal efficiency of PFCs by the present water treatment may be low. Based on the current action value reported by U.S. Environmental Protection Agency, PFOA concentrations found in tap water in Osaka is not expected to pose health risks.

Survey of airborne polyfluorinated telomers in Keihan area, Japan.

Perfluorooctanoate (PFOA) are environmental contaminants posing special public health concerns because of their long-term persistence and bioaccumulation in the environment. Fluorotelomer alcohols are volatile and may undergo long-range transport. Air samples were collected at five sites in the Keihan area, Japan: Sakyo, Morinomiya and three sites in Higashiyodogawa. Except for Higashiyodogawa, the highest concentrations of fluorotelomer alcohols (FTOHs) were for 8:2 FTOH (median 447 pg m(-3)) followed by 10:2 FTOH (56 pg m(-3)) and 6:2 FTOH (22 pg m(-3)). In contrast, 8:2 FTOAcryl (median 865 pg m(-3)) and 8:2 FTOH (1,864 pg m(-3)) were both major components in Higashiyodogawa. Compared to data published for North America and Europe, 8:2 FTOH levels are significantly higher in Keihan, suggesting a possible point source.

Simultaneous analysis of 17 organochlorine pesticides in natural medicines by GC/MS with negative chemical ionization.

Many methods for the determination of pesticide residues in food have been reported. Although natural medicines should be confirmed to be as safe as food, few methods for the determination of pesticide residues in natural medicines have been reported. In this study, 17 organochlorine pesticides were detected in natural medicines using GC/MS with negative chemical ionization (NCI). GC/MS with NCI can detect halogenated pesticides selectively and thus is suitable for the detection of organochlorine pesticides. This study indicates that GC/MS with NCI is useful for analyzing organochlorine pesticides in natural medicines.