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PubMed2002

Analysis of beta-lactam antibiotics by high performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry using bromoform.

The novel identification method for a heat-unstable antibiotic, FC/TA-891 and its active metabolite (FCE22101) by high-performance liquid chromatography (HPLC)-atmospheric pressure chemical ionization mass spectrometry (APCI-MS) employing bromoform as an ionization acceleration solvent, was applied to eight penicillins and 13 cephalosporins which are groups of beta-lactam antibiotics. The conditions of HPLC-APCI-MS were examined with ampicillin. Bromoform or chloroform was added to the mobile phase in HPLC to compare the difference between bromine and chlorine adducted ions. For all penicillins except sulbenicillin, both chlorine adducted and bromine adducted ions were observed with a flow injection method. The results indicated that the relative sensitivity ratios of bromine adducted ions to [M-H](-) were higher than those of chlorine adducted ions. These bromine adduct ions could be clearly distinguished from other ions due to its isotopical ratio (1:1), leading to an easy identification of the compounds. For 13 cephalosporins, bromine adducted ions were detected in nine compounds, and chlorine adducted ions were detected in four compounds. The separation of four antibiotics was investigated with an HPLC column to apply this technique to the actual analysis. The capability was equal as in the flow injection method and it found that this technique, i.e. APCI-MS with bromoform could be applicable in the separation analysis.

Anti-Bacterial Agents↗
PubMed2000

Sonolytic degradation of hazardous organic compounds in aqueous solution.

Benzene, chlorobenzene, 1,2-, 1,3-, 1,4-dichlorobenzene, biphenyl, and polychlorinated biphenyls such as 2-, 4-chlorobiphenyl and 2,2'-dichlorobiphenyl in aqueous solutions have been subjected to sonolysis with 200 kHz ultrasound at an intensity of 6 W cm-2 under an argon atmosphere. 80-90% of initial amount of these compounds were degraded by 30-60 min of sonication when the initial concentrations were 10-100 mumol l-1. The degradation rate of these compounds increased with increase in their vapor pressures. In all cases of sonolysis of chlorinated organic compounds, an appreciable amount of liberated chloride ion was observed.

Journal Article↗
PubMedDate not supplied

Extraction and cleanup methods for analysis of phenolic and neutral organohalogens in plasma.

A method for the analysis of potential endocrine-disrupting compounds, such as phenolic halogenated compounds (e.g., chlorinated and brominated phenols) and hydroxylated PCBs, in blood plasma is presented. Neutral halogenated compounds, specifically brominated diphenyl ethers and PCBs, are also included in the evaluation. An efficient denaturation and extraction step is described, and three methods for lipid removal are evaluated. The latter includes a nondestructive method based on high-resolution gel permeation chromatography (HR-GPC), a newly developed silica gel/sulfuric acid column, and lipid removal by sulfuric acid treatment. Recoveries, based on gas chromatography with an electron capture detector (GC-ECD), were between 70 and 90% for most of the studied compounds. The recoveries of phenolic compounds were generally slightly lower than those of the neutral compounds. The sulfuric acid treatment and silica gel/sulfuric acid column gave the highest yields for acid stable compounds, although a few target compounds were lost during that treatment and all compounds were recovered with the HR-GPC method.

Animals↗
PubMed2002

Oxidation of chlorinated dibenzo-p-dioxin and dibenzofuran by white-rot fungus, Phlebia lindtneri.

The actions of a white-rot fungus on two chlorinated aromatic compounds, known to be persistent environmental contaminants, were studied. Two models, both-ring chlorinated dioxin, 2,7-dichlorodibenzo-p-dioxin (2,7-diCDD) and 2,8-dichlorodibenzofuran (2,8-diCDF), were metabolized by the white-rot fungus Phlebia lindtneri. 2,7-DiCDD disappeared linearly in the culture of P. lindtneri; over a 20-day incubation period, with only 45% remaining in the culture. One of the metabolites produced by P. lindtneri from a 5-day incubated culture with 2,7-diCDD or 2,8-diCDF was identified by gas chromatography-mass spectrometry. P. lindtneri was shown to metabolize 2,7-diCDD and 2,8-diCDF to hydroxy-diCDD and hydroxy-diCDF, respectively.

Basidiomycota↗
PubMed2004

Modeling the formation of chlorination by-products in river waters with different quality.

Water chlorination results in formation of a variety of organic compounds, known as chlorination by-products (CBPs), mainly trihalomethanes (THMs) and haloacetic acids (HAAs). Factors affecting their concentrations have been found to be organic matter content of water, pH, temperature, chlorine dose, contact time and bromide concentration, but the mechanisms of their formation are still under investigation. Within this scope, chlorination experiments have been conducted with river waters from Lesvos island, Greece, with different water quality regarding bromide concentration and organic matter content. The factors studied were pH, time and chlorine dose. The determination of CBPs was carried out by gas chromatography techniques. Statistical analysis of the results was focused on the development of multiple regression models for predicting the concentrations of total trihalomethanes and total HAAs based on the use of pH, reaction time and chlorine dose. The developed models, although providing satisfactory estimations of the concentrations of the CBPs, showed lower correlation coefficients than the multiple regression models developed for THMs only during previous study. It seems that the different water quality characteristics of the two river waters in the present study is responsible for this phenomenon. The results indicate that under these conditions the formation of THMs and HAAs in water has a more stochastic character, which is difficult to be described by the conventional regression techniques.

Bromides↗
PubMed2003

Estimates of total polychlorinated biphenyl (PCB) compounds in soils/sediments by hydrogenolysis to dicyclohexyl.

A method to determine the total PCB content by hydrogenolysis (hydrodechlorination and hydrogenation) of chlorinated biphenyl compounds was extended to natural particulate matrices (soil and sediment). The contaminated soil was suspended in hexane in the presence of Pd/gamma-Al2O3 in a hydrogen atmosphere then permitted to react for one hour at 65 degrees C. Dicyclohexyl, recovered in the hexane, was quantified by gas chromatography mass spectrometry. The reaction was very efficient for soil/sediment in hexane suspension and virtually complete provided that excess catalyst was added to samples that were burdened with higher PCB loadings prior to reaction otherwise some partial hydrogenation of biphenyl was also observed. The proposed method was validated with the analysis of five certified reference materials.

Environmental Monitoring↗
PubMed2004

A new approach to evaluating the toxicity and genotoxicity of disinfected drinking water.

The aim of this study was to evaluate the formation of toxic and genotoxic compounds in surface drinking waters treated with two widely used disinfectants, sodium hypochlorite (NaClO) and chlorine dioxide (ClO(2)), and a new disinfectant, peracetic acid (PAA). For this purpose a pilot plant was set up to add these biocides continuously to pre-filtered lake water flowing into three different basins. During three seasonal experiments, short-term in vivo tests (with plant, fish and molluscs) and in vitro tests (with bacteria, yeast and human cells) were carried out to evaluate the formation of genotoxic disinfection by-products (DBPs). Gas chromatography/mass spectrometry (GC/MS) was used to identify DBPs produced during the different treatments, microbiological analyses were performed to test the biocidal activity of the disinfectants, and chemical analyses were carried out to evaluate the quality of the water. The pilot drinking water plant under study was useful in studying the toxicity and genotoxicity of disinfected drinking water with this combined chemical/biotoxicological approach. This paper describes the setting up of the pilot plant and sets out/reports the results of the microbiological and chemical analyses.

Animals↗
PubMed2003

Biodegradation of chlorinated solvents in a water unsaturated topsoil.

In order to investigate topsoils as potential sinks for chlorinated solvents from the atmosphere, the degradation of trichloromethane (CHCl(3)), 1,1,1-trichloroethane (CH(3)CCl(3)), tetrachloromethane (CCl(4)), trichloroethene (C(2)HCl(3)) and tetrachloroethene (C(2)Cl(4)) was studied in anoxic laboratory experiments designed to simulate denitrifying conditions in water unsaturated topsoil. Active denitrification was demonstrated by measuring the release of 15N in N(2) to the headspace from added 15N labeled nitrate. The degradation of chlorinated aliphatic compounds was followed by measuring their concentrations in the headspace above the soil. The headspace concentrations of all the chlorinated solvents except CH(3)CCl(3) were significantly (P<or=0.05) lower after 41 days in biologically active batches as compared to sterile batches. For the compounds with significantly decreasing headspace concentrations, the decline was the least for CHCl(3) within the 41 days of incubation. The headspace concentrations of trichloro- and tetrachloroethene decreased more than 50% during the first 20 days with no considerable indication of abiotic transformation. While slow abiotic removal was observed, tetrachloromethane was completely biotransformed after 16 days. Based on the results in this study, we conclude that anaerobic topsoils are potential sinks for these contaminants, and that a natural attenuation potential exists, even in water unsaturated topsoils.

Biodegradation, Environmental↗
PubMed2002

Natural attenuation of chlorinated solvents at Area 6, Dover Air Force Base: groundwater biogeochemistry.

Monitored natural attenuation (MNA) has recently emerged as a viable groundwater remediation technology in the United States. Area 6 at Dover Air Force Base (Dover, DE) was chosen as a test site to examine the potential for MNA of tetrachloroethene (PCE) and trichloroethene (TCE) in groundwater and aquifer sediments. A "lines of evidence" approach was used to document the occurrence of natural attenuation. Chlorinated hydrocarbon and biogeochemical data were used to develop a site-specific conceptual model where both anaerobic and aerobic biological processes are responsible for the destruction of PCE, TCE, and daughter metabolites. An examination of groundwater biogeochemical data showed a region of depleted dissolved oxygen with elevated dissolved methane and hydrogen concentrations. Reductive dechlorination likely dominated in the anaerobic portion of the aquifer where PCE and TCE levels were observed to decrease with a simultaneous increase in cis-1,2-dichloroethene (cis-DCE), vinyl chloride (VC), ethene, and dissolved chloride. Near the anaerobic/ aerobic interface, concentrations of cis-DCE and VC decreased to below detection limits, presumably due to aerobic biotransformation processes. Therefore, the contaminant and daughter product plumes present at the site appear to have been naturally atteuated by a combination of active anaerobic and aerobic biotransformation processes.

Bacteria, Aerobic↗
PubMed2006

Temporal trends and relationships of particulate chlorinated polycyclic aromatic hydrocarbons and their parent compounds in urban air.

Concentrations of 12 chlorinated polycyclic aromatic hydrocarbons (CIPAHs) and the corresponding 5 parent PAHs associated with particulates in urban air in Shizuoka, Japan, were investigated from 1992 to 2002. Among the seven target CIPAHs that were detected in the air samples, 6-chlorobenzo[a]pyrene (6-ClBaP) had the highest mean concentration (15 pg m(-3)), followed by 1-chloropyrene (5.2 pg m(-3)) and 7-chlorobenz[a]anthracene (3.1 pg m(-3)). The concentrations of all the ClPAHs and PAHs, except 6-ClBaP, were higher in winter than in summer. Over the study period, the concentrations of the CIPAHs, except 6-ClBaP, remained almost constant, whereas the parent PAH concentrations declined moderately. There was significant correlation between the concentrations of the ClPAHs (except 3,9- and 9,10-dichlorophenanthrene) and the concentrations of the corresponding parent PAHs. Compositional analysis showed that the proportions of the detected PAHs generally did not vary over the period, whereas the proportion of 6-ClBaP relative to the total ClPAH concentration decreased over time. Comparison of the concentration profile of certain ClPAHs normalized to the concentration of 3-chlorofluoranthene, which is relatively photostable, with the profile for a traffic air sample reported previously revealed that there was no similarity between the two profiles. Factor analysis indicated that the atmospheric behavior of the ClPAHs, except for 6-ClBaP, may be similar to that of the parent PAHs, and that the atmospheric behavior of 6-ClBaP may differ from that of the other ClPAHs. The factor analysis also suggested that the emission sources for the ClPAHs (except for 6-CIBaP) may be similar to the sources of the parent PAHs.

Air↗
PubMed1995

Explosion risk from swimming pool chlorinators and review of chlorine toxicity.

Two patients were admitted to the hospital emergency room in respiratory distress after an accidental explosion involving chlorinating agents for the swimming pool. The two primary agents involved were calcium hypochlorite and trichloro-s-triazinetrione; both are commonly used chlorinating agents. These chemicals were tested in a bomb apparatus measuring temperature and gas production. Combining the two chlorinators at 2, 6, 12, or 18 g of each produced a progressive increase in gas production from 234 to 1422 mL. The temperature increased from 30 degrees C at 2 g to 63 degrees C at 18 g. The time to complete the reaction decreased from 6.2 minutes at 2 g to 3.8 minutes at 18 g. The third run at the 18 g level resulted in an explosion. The results indicate that gas generation is dependent on both products. The addition of organic material was abandoned because of the explosive nature of the reaction. The amount of calcium hypochlorite primarily determines the rate of reaction and heat generation. Appropriate emergency action and treatment for chlorine gas is discussed.

Adult↗
PubMed2001

Identification and quantification of chlorinated bisphenol A in wastewater from wastepaper recycling plants.

Chlorinated derivatives of bisphenol A were detected in the final effluents of eight paper manufacturing plants in Shizuoka, Japan, where thermal paper and/or other printed paper is used as the raw material. Their amounts were determined by gas chromatography/mass spectrometry (GC/MS) after treatment with N, O-bis(trimethylsilyl)trifluoroacetamide, and ranged from traces to 2.0 microg/l. They are likely produced by chlorination of bisphenol A, which was released into the effluents from the pulping process of wastepaper, during or after bleaching with chlorine.

Benzhydryl Compounds↗