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1.
J Environ Sci Health B ; 52(1): 10-22, 2017 Jan 02.
Article in English | MEDLINE | ID: mdl-27628767

ABSTRACT

This study was performed to identify the degradation products of profenofos "a phenyl organothiophosphate insecticide" in raw water (RW) collected from the entry point of Metropolitan Water Works Authority "Bangkaen, Thailand" and ultrapure water (UPW) with and without TiO2 under simulated sunlight irradiation. Degradation of profenofos was followed with ultrahigh performance liquid chromatography (UHPLC) and follows pseudo first-order kinetic. Accordingly, high-field FTICR mass spectrometry coupled to an electrospray ionization source was used to reveal the degradation routes of profenofos and the isotopic fine structures (IFS) elucidations to approve the chemical structures of its degradation products. More degradation products were detected in UPW as compared to RW. Consequently, two main degradation pathways namely (i) interactive replacements of bromine and hydrogen by hydroxyl functional groups and (ii) rupture of PO, PS, CBr and CCl bonds were observed. None interactive replacement of chlorine by hydroxyl functional group was detected. Accordingly, mechanistical pathways of the main degradation products were established.


Subject(s)
Chromatography, Liquid/methods , Insecticides/analysis , Mass Spectrometry/methods , Organothiophosphates/analysis , Water Pollutants, Chemical/analysis , Hydrogen-Ion Concentration , Insecticides/metabolism , Kinetics , Organothiophosphates/metabolism , Photolysis , Sunlight , Thailand , Titanium/chemistry
2.
Article in English | MEDLINE | ID: mdl-23647117

ABSTRACT

The degradation of a paracetamol (N-acetil-para-aminofenol) aqueous solution (C (0) P = 5 mmol L(-1)) is studied in a bench-scale setup by means of simple ozonation (O3) and ozonation catalyzed with UV light (O3/UV) in order to quantify the influence of UV light on the degradation process. The results have shown that under the adopted experimental conditions (25°C, applied ozone dose = 9.8 mg L(-1) and gas flow rate of 20 L h(-1)) both oxidative systems are capable of removing the substrate with mineralization degrees up to 51% for ozonation and 53% for O3/UV. HPICE chromatography allowed the detection of nitrate ions and maleic and oxalic acids as ultimate carboxylic acids. The experimental data have been interpreted through 5 indicators: the conversion of paracetamol (XP ), the conversion degree of TOC (XTOC ), the apparent rate constant (kap ), the Hatta number (Ha) and the enhancement factor (E). The main advantage of photo-ozonation compared to simple ozonation was a more advanced conversion (79% vs. 92% after 90 min). The paracetamol decay follows a pseudo-first-order reaction with a superior rate constant (higher by 54%) for the UV catalyzed system in comparison with direct ozonation. Mineralization is slightly accelerated (+4%) in the O3/UV system, due to the additional production of hydroxyl radicals induced by the UV light and a higher Hatta number (+24%). Nevertheless, the process was still in the slow reaction kinetic regime (Ha < 0.3), and the enhancement factor was not significantly increased. The results are useful for the design and scale-up of the gas-liquid processes.


Subject(s)
Acetaminophen/chemistry , Ozone/chemistry , Photolysis , Ultraviolet Rays , Oxidation-Reduction
3.
ChemMedChem ; 2(6): 890-7, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17394264

ABSTRACT

Polychlorinated dibenzo-p-dioxins are persistent environmental pollutants. The most potent congener, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), causes a wasting syndrome and is a potent carcinogen and immunosuppressant in the rat at high doses. However, low doses cause opposite effects to some of those observed at higher doses, resulting in chemoprevention, stimulation of the immune system, and longevity in experimental animals. The new TCDD analogue, 2,3,7,8-tetrachlorophenothiazine (TCPT), was developed to take advantage of the low-dose effects of dioxins that have potential application as therapeutics. Its development marked a deviation from the traditional scope of phenothiazine drug design by deriving biological effects from aryl substituents. TCPT was synthesized in three steps. The key ring-closing step was performed utilizing a Buchwald-Hartwig amination to provide TCPT in 37% yield. Its potency to induce CYP1A1 activity over 24 h was 370 times lower than that of TCDD in vitro. The elimination half-life of the parent compound in serum was 5.4 h in the rat and 2.7 h in the guinea pig, compared to 11 and 30 days, respectively, for TCDD. These initial findings clearly differentiate TCPT from TCDD and provide the basis for further studies of its potential as a drug lead.


Subject(s)
Drug Design , Phenothiazines/chemical synthesis , Polychlorinated Dibenzodioxins/analogs & derivatives , Polychlorinated Dibenzodioxins/chemical synthesis , Animals , Cell Line, Tumor , Chlorpromazine/chemistry , Cytochrome P-450 CYP1A1/biosynthesis , Dioxins/chemistry , Enzyme Induction , Female , Guinea Pigs , Phenothiazines/adverse effects , Polychlorinated Dibenzodioxins/adverse effects , Polychlorinated Dibenzodioxins/blood , Rats , Rats, Sprague-Dawley
4.
Talanta ; 72(5): 1650-4, 2007 Jul 31.
Article in English | MEDLINE | ID: mdl-19071811

ABSTRACT

Triclosan in the waste, river and sea water samples collected in Hong Kong was analyzed by using gas chromatography-ion trap mass spectrometry method. (13)C(12)-triclosan was used as internal standard for the quantitative analysis. Water samples were prepared and cleaned-up by using a C(18) solid-phase extraction cartridge. The recoveries of triclosan in spiked coastal water at three different concentrations ranged from 83 to 110%. The method detection limit was 0.25 ng/L for triclosan in 1-L water and the relative standard deviations and relative error were less than 11.0 and 12.3%, respectively (n=3). The method was successfully applied to analyze water samples collected from rivers, coastal water bodies and wastewater treatment plants at ng/L levels.

5.
J Chromatogr A ; 1133(1-2): 112-8, 2006 Nov 10.
Article in English | MEDLINE | ID: mdl-16934272

ABSTRACT

An on-line immunoaffinity column with liquid chromatography/tandem mass spectrometry (IAC-LC-MS/MS) method for the determination of diuron in water matrices was described. This method used a sol-gel immunoaffinity column (20 mm x 4 mm I.D.) for on-line sample cleanup and enrichment, a monolithic analytical column (100 mm x 4.6 mm I.D.) for separation, and a triple quadrupole mass spectrometer for quantitation. The major challenges for the on-line set-up were discussed. The optimized on-line protocol was emphasized by the fact that low limit of quantitation (LOQ) of 1.0 ng/L was achieved with only 2.5-mL sample. In addition, a satisfactory accuracy ( approximately 90% of recovery) and precision (<6% of relative standard deviation) at 50 ng/L concentration were also obtained. Due to the ability of the sol-gel immunoaffinity column to eliminate matrix effect, the on-line IAC-LC-MS/MS analysis method can reliably determine diuron in wastewater treatment plant effluent sample.


Subject(s)
Chromatography, Affinity/methods , Chromatography, Liquid/methods , Diuron/analysis , Industrial Waste/analysis , Mass Spectrometry/methods , Immunochemistry , Mass Spectrometry/instrumentation , Reproducibility of Results
6.
Electrophoresis ; 27(11): 2216-24, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16736456

ABSTRACT

Metal working fluids (MWFs) are widely used as lubricants and coolants for different industrial operations. Biocides are ingredients of MWFs to control the microbial growth; derivatives of hexahydrotriazines and oxazolidines are generally used. Because of the lack of appropriate characterization, an existing capillary electrophoretic method for their quantification was improved. During the process of optimization, it became clear that hydrolysis products, derivatives of amino alcohols, severely interfere with the separation procedure. Since indirect-UV detection lacked the required selectivity, mass-selective detection was employed. NMR and MS established the absence of amino alcohols in the original educts. The aqueous solutions of the biocides stored for extended time remained amino alcohol-free, suggesting that these amino alcohols are formed from the biocides during the capillary electrophoretic separation. The observation of narrow and symmetric peaks indicated hydrolysis, and the polarity of the products implied favorable conditions for capillary electrophoretic separation. Methods were optimized for the analysis of the amino alcohols, the hydrolytic products of the formaldehyde releasers, using indirect-UV and MS detection. This method was extended to other likely solutes used as alkaline-reserve ingredients. The analytes were separated within 9 min with a high precision of migration times (the RSDs were below 1.5%). When quantifying from mobility scale, the calibration curves produced linearity with regression coefficients in the range of 0.990-0.999. The detection limit was lower than 1 mg/L in the case of MS detection. The influence of water-based MWF was also investigated, and no matrix effect on the migration of the analytes and on the peak areas was observed.


Subject(s)
Amino Alcohols/analysis , Electrophoresis, Capillary/methods , Formaldehyde/chemistry , Industrial Oils/analysis , Magnetic Resonance Spectroscopy/methods , Hydrolysis , Lubrication , Metals/chemistry , Sensitivity and Specificity
7.
Electrophoresis ; 27(5-6): 1237-47, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16523461

ABSTRACT

A method for the determination of low-molecular-weight amines from indoor and ambient air was developed using a concentration device followed by CE coupled with indirect spectrophotometric and mass spectrometric detection that enables a reliable, rapid-response and easy-to-operate method. In indirect detection method, the selected amines were separated from interfering metal ions and amino alcohols present in the samples with an imidazole-based buffer with ethanol and EDTA as modifier. By replacing imidazole with ammonium, the final buffer was applicable for MS detection for the analytes with m/z higher than 50. A novel monolithic polymer material based on poly(methacrylate-acrylate) copolymer was developed for sampling short-chain amines from the gaseous phase. The selected analysis conditions were applied to quantify the selected short-chain amines with detection limits for the whole procedure determined between 1 and 2 microg/filter when 40 L air was sampled with 1 L/min velocity. Improved linearity and precision were obtained when the raw, time-scaled electropherogram data were transformed into mobility-scale applied for the determination of the performance characteristics of the methods. The applicability of the process of data transformation into the mobility scale was demonstrated by studying the matrix effect of water-miscible metal working fluid (stable water-oil emulsion) and of ambient air as real samples. CE-indirect UV and CE-MS, combined with the possibility of rapid air sampling, can be useful for the estimation of short-term exposure of the selected biogenic amines.


Subject(s)
Air Pollutants, Occupational/analysis , Biogenic Amines/analysis , Electrophoresis, Capillary/methods , Acrylic Resins , Adsorption , Aerosols , Air Pollution, Indoor/analysis , Biogenic Amines/chemistry , Mass Spectrometry , Metallurgy , Molecular Weight , Polymethacrylic Acids , Spectrophotometry, Ultraviolet
8.
Environ Sci Technol ; 40(1): 342-9, 2006 Jan 01.
Article in English | MEDLINE | ID: mdl-16433370

ABSTRACT

Nonstationary combustion conditions at municipal solid waste incineration (MSWI) plants cause increased crude gas concentrations of polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), and other products of incomplete combustion (PIC). Such transient conditions occur, e.g., during and after start-up processes in MSWI plants. The start-up and shut-down processes of a MSWI plant were investigated in detail. PCDD/F and other PIC concentrations were determined in the crude gas, in the boiler ash, and in the ash from the electrostatic precipitator (ESP ash), with the outcome that only the start-up procedure significantly affected the concentrations of the organic pollutants in the flue gas and in the ESP ash. The shut-down procedure was evaluated as less problematic for the concentration of the organic pollutants. Moreover the concentration of the PCDD/F and other PIC in the boiler ash was determined as not influenced by shut-down and start-up processes. The homologue profiles and the congener patterns as well as the PCDF/PCDD ratio in the flue gas and in the ESP ash change during MSWI start-up. The changing patterns point at a transition from dominant de novo synthesis to precursor synthesis.


Subject(s)
Benzofurans/analysis , Carbon , Gases , Incineration , Polychlorinated Dibenzodioxins/analogs & derivatives , Air Pollutants/analysis , Air Pollutants/chemistry , Cities , Coal Ash , Dibenzofurans, Polychlorinated , Hazardous Waste/analysis , Industrial Waste , Particle Size , Particulate Matter , Plants , Polychlorinated Dibenzodioxins/analysis
9.
J Chromatogr A ; 1102(1-2): 84-90, 2006 Jan 13.
Article in English | MEDLINE | ID: mdl-16300773

ABSTRACT

An immunosorbent was fabricated by encapsulation of monoclonal anti-isoproturon antibodies in sol-gel matrix. The immunosorbent-based loading, rinsing and eluting processes were optimized. Based on these optimizations, the sol-gel immunosorbent (SG-IS) selectively extracted isoproturon from an artificial mixture of 68 pesticides. In addition to this high selectivity, the SG-IS proved to be reusable. The SG-IS was combined with liquid chromatography-tandem mass spectrometry (LC-MS-MS) to determine isoproturon in surface water, and the linear range was up to 2.2 microg/l with correlation coefficient higher than 0.99 and relative standard deviation (RSD) lower than 5% (n=8). The limit of quantitation (LOQ) for 25-ml surface water sample was 5 ng/l.


Subject(s)
Gels , Herbicides/analysis , Phenylurea Compounds/analysis , Water Pollutants, Chemical/analysis , Calibration , Sensitivity and Specificity
10.
J Trace Elem Med Biol ; 19(2-3): 183-9, 2005.
Article in English | MEDLINE | ID: mdl-16325534

ABSTRACT

Royal jelly from Apis mellifera is a highly active natural biological substance and is probably one of the most interesting raw substances in natural product chemistry. Trace elements play a key role in the biomedical activities associated with royal jelly, as these elements have a multitude of known and unknown biological functions. For this reason concentrations of 28 trace (Al, Ba, Sr, Bi, Cd, Hg, Pb, Sn, Te, Tl, W, Sb, Cr, Ni, Ti, V, Co, Mo) and mineral (P, S, Ca, Mg, K, Na, Zn, Fe, Cu, Mn) elements were systematically investigated in botanically and geologically defined royal jelly samples. In addition, concentrations of 14 trace elements were measured in the associated honey samples--honey being the precursor of royal jelly. Concentrations of K, Na, Mg, Ca, P, S, Cu, Fe, Zn, Al, Ba and Sr in royal jelly were determined by inductively coupled plasma optical emission spectroscopy (ICP-OES), while concentrations of Bi, Cd, Hg, Pb, Sn, Te, Tl, W, Sb, Cr, Mn, Ni, Ti, V, Co and Mo in royal jelly were determined by double focusing magnetic sector field inductively coupled plasma mass spectrometry (SF-ICP-MS). In the honey samples, trace and mineral element concentrations strongly depended on botanical and geological origin, and substantial variation was found. In contrast, the concentrations of trace and mineral elements were highly constant in the associated royal jelly samples. The most important results were the homeostatic adjustments of trace and mineral element concentrations in royal jelly. This effect was evidently produced in the endocrine glands of nurse bees, which are adapted for needs of bee larvae. In conclusion, this research yielded a surprising and completely new finding--that royal jelly, as a form of lactation on the insect level, shows the same homeostatic adjustment as mammalian and human breast milk.


Subject(s)
Chemistry Techniques, Analytical/methods , Fatty Acids/metabolism , Minerals/analysis , Trace Elements , Animals , Bees/metabolism , Elements , Homeostasis , Mass Spectrometry , Temperature
11.
Sci Total Environ ; 349(1-3): 120-8, 2005 Oct 15.
Article in English | MEDLINE | ID: mdl-16198674

ABSTRACT

Numerous environmental pollutants have been detected for estrogenic activity by interacting with the estrogen receptor, but little information is available about their interactions with the progesterone receptor. In this study, emission samples generated by fossil fuel combustion (FFC) and air particulate material (APM) collected from an urban location near a traffic line in a big city of China were evaluated to interact with the human progesterone receptor (hPR) signaling pathway by examining their ability to interact with the activity of hPR expressed in yeast. The results showed that the soot of a petroleum-fired vehicle possessed the most potent anti-progesteronic activity, that of coal-fired stove and diesel fired agrimotor emissions took the second place, and soot samples of coal-fired heating work and electric power station had lesser progesterone inhibition activity. The anti-progesteronic activity of APM was between that of soot from petroleum-fired vehicle and soot from coal-fired establishments and diesel fired agrimotor. Since there was no other large pollution source near the APM sampling sites, the endocrine disrupters were most likely from vehicle emissions, tire attrition and house heating sources. The correlation analysis showed that a strong relationship existed between estrogenic activity and anti-progesteronic activity in emissions of fossil fuel combustion. The discoveries that some environmental pollutants with estrogenic activity can also inhibit hPR activity indicate that further studies are required to investigate potential mechanisms for the reported estrogenic activities of these pollutants.


Subject(s)
Air Pollutants , Carbon , Fossil Fuels , Receptors, Progesterone/antagonists & inhibitors , Vehicle Emissions , Dust , Gene Expression , Humans , Progesterone/pharmacology , Receptors, Progesterone/genetics , Receptors, Progesterone/metabolism , Saccharomyces cerevisiae/drug effects , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Transfection , beta-Galactosidase/metabolism
12.
Anal Bioanal Chem ; 383(5): 787-96, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16237543

ABSTRACT

High-performance liquid chromatography-tandem mass spectrometry has been used to identify isoflavone aglycones and glycosides in kudzu root. Fourteen isoflavones were detected. Among these, six were identified by comparison with authentic standards. Tentative identifications of the other isoflavones are based on UV spectra, mass spectra of protonated and deprotonated molecules, and MS-MS data. Several are reported for the first time in kudzu root. The bioactivity and bioavailability of isoflavone aglycones are usually greater than those of their glycosides. To improve the bioavailability of kudzu root isoflavones, crude beta-glycosidases prepared from microbes were used to hydrolyze the isoflavone glycosides. Several MS modes are combined not only to identify the isoflavones in kudzu root, but also to describe the biotransformation of kudzu root isoflavone glycosides. It is also proved that crude beta-glycosidases have high selectivity toward the O-glycosides of isoflavones.


Subject(s)
Chromatography, High Pressure Liquid/methods , Isoflavones/analysis , Isoflavones/metabolism , Mass Spectrometry/methods , Plant Roots/metabolism , Pueraria/metabolism , Spectrophotometry, Ultraviolet/methods , Biotransformation , Reproducibility of Results , Sensitivity and Specificity
13.
Anal Bioanal Chem ; 382(8): 1919-33, 2005 Aug.
Article in English | MEDLINE | ID: mdl-16047192

ABSTRACT

Five new rat monoclonal antibodies (mAbs) for 2,4,6-trinitrotoluene (TNT) and other nitroaromatic compounds, including, especially, the metabolite 2-amino-4,6-dinitrotoluene (2-ADNT), are described. Five heterogeneous, competitive enzyme-linked immunosorbent assays (ELISAs) were developed. Assay 1 uses mAb DNT4 3F6 as recognition element and gives a standard curve for TNT in 40 mmol L(-1) phosphate buffered saline (PBS) with a test midpoint (IC50) of 0.26+/-0.08 microg L(-1) (n=20). Assay 2 (mAb DNT4 4G4) has an IC50 of 0.35+/-0.07 microg L(-1) (n=18), assay 3 (mAb DNT4 1A3) has an IC50 of 0.73+/-0.14 microg L(-1) (n=15), and assay 4 (mAb DNT4 1A7) has an IC50 of 2.32+/-0.70 microg L(-1) (n=15). Assay 5 (mAb DNT2 4B4) is very selective for 2-ADNT and has an IC50 of 8.5+/-1.7 microg L(-1) (n=15) in PBS. These antibodies for nitroaromatic compounds differ not only in their sensitivity but also in their selectivity. Major cross-reactants are 1,3,5-trinitrobenzene, 2-ADNT, 4-amino-2,6-dinitrotoluene (4-ADNT), 2,4-dinitroaniline, 3,5-dinitroaniline, and 2,6-dinitroaniline. Although assay 5 is not highly sensitive, the mAb DNT2 4B4 in this assay is highly selective for 2-ADNT. Of all the compounds tested, only 2,4-dinitroaniline and 3,5-dinitroaniline had relevant cross reactivities, 18% and about 26%, respectively. Two ELISAs, using mAbs DNT4 3F6 and DNT2 4B4, were used to analyze different concentrations of TNT and 2-ADNT, respectively, in three different surface water matrices (river and lake water). Both assays were affected by the matrix, but usually performed well (recovery within the range 70-120%). In addition, these ELISAs were used to analyze mixtures of TNT, 2-ADNT, and 4-ADNT, at three different concentrations, in the same water matrices. A different recognition pattern was clearly visible with both assays and depended on the cross reactivities of the corresponding mAb.


Subject(s)
Aniline Compounds/analysis , Antibodies, Monoclonal/chemistry , Antibody Specificity , Enzyme-Linked Immunosorbent Assay/methods , Trinitrotoluene/analysis , Animals , Haptens/chemistry , Nitro Compounds/analysis , Rats , Sensitivity and Specificity , Water/analysis
14.
Chemosphere ; 61(5): 741-51, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16019053

ABSTRACT

The aim of this work was to evaluate the effect of linear alkylbenzene sulfonate (LAS, 200 mg l(-1)) on the fate of phenanthrene in a model ecosystem "water-lava-hydrophytes-air". The experiments were conducted using two closed cultivation chamber systems. Rushes (Juncus effesus) were selected as a representative hydrophyte. Five hundred micrograms per liter of phenanthrene in a culture solution containing a 14C-activity of 75 microCi per chamber was applied (i) to investigate the degradation of the labeled test substance and the transfer processes within the system; (ii) to determine the mass-balance possible and (iii) to detect the occurrence of volatile test substances, their volatile metabolites and the degradation end-product CO2 in the gas phase. Most of the applied 14C-activity was found in the plant (41-45%), in which approximately 95% was associated with plant roots and approximately 5% with shoots. The 14C-activity recovered in the form of VOCs and CO2 was measured in lava (18-29%, 8-11%), and in the culture solution (10-14% and 1%), respectively. Majority of the applied 14C-activity existed in two forms, i.e. (1) polar metabolites (26%), of which 91% were found in plant roots, and (2) un-extractable residues (23%), most of which were in plant roots (40%) and bounded to lava (58%). The presence of LAS significantly increased the volatilization of phenanthrene and its metabolites, inhibited its mineralization and decreased the level of 14C-activity in lava. Moreover, LAS reduced the phenanthrene level in plant roots.


Subject(s)
Alkanesulfonic Acids/chemistry , Environmental Pollutants/metabolism , Phenanthrenes/metabolism , Plant Roots/metabolism , Plant Shoots/metabolism , Air , Biodegradation, Environmental , Carbon Radioisotopes , Ecosystem , Magnoliopsida/metabolism , Surface-Active Agents/chemistry , Volatilization , Water
15.
Biosens Bioelectron ; 21(2): 354-64, 2005 Aug 15.
Article in English | MEDLINE | ID: mdl-16023963

ABSTRACT

This paper presents a new, versatile, portable miniaturized flow-injection immunosensor which is designed for field analysis. The temperature-controlled field prototype can run for 6h without external power supply. The bio-recognition element is an analyte-specific antibody immobilized on a gold surface of pyramidal structures inside an exchangeable single-use chip, which hosts also the enzyme-tracer and the sample reservoirs. The competition between the enzyme-tracer and the analyte for the antigen-binding sites of the antibodies yields in the final step a chemiluminescence signal that is inversely proportional to the concentration of analyte in the given range of detection. A proof of principle is shown for nitroaromatics and pesticides. The detection limits (DL; IC20) reached with the field prototype in the laboratory was below 0.1 microg l(-1) for 2,4,6-trinitrotoluene (TNT), and about 0.2 microg l(-1) for diuron and atrazine, respectively. Important aspects in this development were the design of the competition between analyte and enzyme-tracer, the unspecific signal due to unspecific binding and/or luminescence background signal, and the flow pattern inside the chip.


Subject(s)
Atrazine/analysis , Biosensing Techniques/instrumentation , Diuron/analysis , Environmental Monitoring/instrumentation , Environmental Pollution/analysis , Enzyme-Linked Immunosorbent Assay/instrumentation , Trinitrotoluene/analysis , Biosensing Techniques/methods , Environmental Monitoring/methods , Enzyme-Linked Immunosorbent Assay/methods , Equipment Design , Equipment Failure Analysis , Feasibility Studies , Flow Injection Analysis/instrumentation , Flow Injection Analysis/methods , Microfluidic Analytical Techniques/instrumentation , Microfluidic Analytical Techniques/methods
16.
Environ Sci Technol ; 39(9): 3345-50, 2005 May 01.
Article in English | MEDLINE | ID: mdl-15926588

ABSTRACT

Co-combustion of coal and waste in power plants poses both environmental and economic challenges, especially because of the high polychlorinated dibenzo-p-dioxin and furan (PCDD/F) emissions from solid waste. In this study, we performed a series of experiments focusing on the prevention of PCDD/F formation by the use of various inhibitors added to the fuel before combustion. A mixture of lignite coal, solid waste, and poly(vinyl chloride) (PVC) was thermally treated in a laboratory-scale furnace at 400 degrees C. Twenty different additives were investigated at a level of 10 wt% of the total fuel during the experiments. We have divided them into four general groups according to their chemical nature: metal oxides, N-containing compounds, S-containing compounds, and N- and S-containing compounds. The resulting values showed a significant reduction of PCDD/F levels when N- and S-containing compounds were used as additives to the fuel. Principle component analysis (PCA) was used to illustrate the effect of the 20 different inhibitors on the congener patterns emitted. As a result, the most effective inhibitors for PCDD/F formation in flue gases were determined to be (NH4)2SO4 and (NH4)2S2O3; they are inexpensive and nontoxic materials. Both compounds can suppress the formation of toxic compounds such as PCDD/Fs by more than 98-99%, and the most toxic PCDD/F congeners were not detectable in most of the samples. Thus, these compounds were also studied as a lower percentage of the fuel. (NH4)2SO4 resulted in a greater than 90% reduction of PCDD/F even when composing only 3% of the fuel combusted. However, less than 5% (NH4)2S2O3 resulted in far weaker inhibition. The PCDD/F homologue distribution ratio for samples with varying percentages of (NH4)2SO4 and (NH4)2S2O3 was also investigated. Higher percentages of the inhibitors produced a lower percentage of lower chlorinated PCDDs. The opposite effect was found for PCDFs.


Subject(s)
Benzofurans/chemistry , Coal , Incineration , Polychlorinated Dibenzodioxins/analogs & derivatives , Polychlorinated Dibenzodioxins/chemistry , Air Pollution/prevention & control , Benzofurans/analysis , Dibenzofurans, Polychlorinated , Polychlorinated Dibenzodioxins/analysis , Soil Pollutants/analysis
17.
Electrophoresis ; 26(7-8): 1523-32, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15776478

ABSTRACT

A quantitative, specific, and sensitive method for the determination of N-acylhomoserine lactones (HSLs - a group of bacterial semiochemicals) in the form of their hydrolysis products (N-acylhomoserines, HSs) is presented. Real samples were analyzed by capillary zone electrophoresis-mass spectrometry (CZE-MS) after alkaline lactonolysis and extraction by mixed-mode anion-exchange solid-phase extraction. The presented cleanup significantly speeds up the HSL extraction procedure, strongly reduces sample consumption, and is more selective compared to the commonly used liquid/liquid extraction. Completeness of the hydrolysis reaction was examined by nuclear magnetic resonance spectroscopy. This CZE-MS method complements recently published capillary separation techniques (nano liquid chromatography-MS, partial-filling micellar electrokinetic chromatography-MS, gas chromatography-MS) and provides a possibility to differentiate quantitatively between the homoserines (as naturally occurring degradation products) besides the intact homoserine lactones. The method was found to be quantitative down to a concentration of 0.05 microg/mL (limit of quantification), while the limit of detection was determined with 0.01 microg/mL - sufficient for the analysis of culture supernatants.


Subject(s)
4-Butyrolactone/analogs & derivatives , Alkalies/chemistry , Chromatography, Ion Exchange/methods , Electrophoresis, Capillary/methods , Mass Spectrometry/methods , 4-Butyrolactone/analysis , Anion Exchange Resins , Chromatography, Ion Exchange/instrumentation , Hydrolysis , Magnetic Resonance Spectroscopy
18.
Anal Bioanal Chem ; 381(8): 1609-18, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15770472

ABSTRACT

Exposure to indoor air pollution (IAP) from the combustion of biomass fuels is an important cause of morbidity and mortality in developing countries. In the work discussed in this paper we evaluated the endocrine activity of soot particles from biomass fuels by using yeast bioassay. These pollutants could have beta-galactosidase activity with a relative potency (RP) about 10(-7)-10(-9) that of estradiol. Soot particles from wood and straw combustion only partially induced beta-galactosidase activity whereas others produced fully inductive activity in the yeast assay system. These pollutants did not have estrogen antagonist and progesterone agonist activity within the defined concentration range. However, these pollutants require 2-4 orders of magnitude higher IC50 to inhibit the activity of progesterone in a similar dose-response manner to mifepristone. We therefore propose that the endocrine activity of some environmental pollutants may be because of inhibition of the progesterone receptor (hPR). GC-MS results showed that substituted polycyclic aromatic hydrocarbon (PAH) compounds, substituted phenolic compounds and derivatives, aromatic carbonyl compounds, and phytosteroids in these soot particles may be mimicking endogenous hormones.


Subject(s)
Air Pollutants/pharmacology , Carbon/pharmacology , Estrogen Antagonists/pharmacology , Estrogens/agonists , Progesterone/agonists , Progesterone/antagonists & inhibitors , Air Pollutants/chemistry , Biological Assay , Carbon/chemistry , China , Energy-Generating Resources , Estrogen Antagonists/analysis , Estrogens/analysis , Plant Stems , Poaceae , Progesterone/analysis , Saccharomyces cerevisiae , Wood
19.
Environ Toxicol Chem ; 23(10): 2309-17, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15511093

ABSTRACT

Owing to the importance of octanol-air partition coefficients (KOA) in describing the partition of organic pollutants from air to environmental organic phases, the paucity of KOA data at different environmental temperatures, and the difficulty or high expenditures involved in experimental determination, the development of predictive models for KOA is necessary. Approaches such as this are greatly needed to evaluate the environmental fate of the ever-increasing list of production chemicals. Partial least squares (PLS) regression with 18 molecular structural descriptors was used to develop predictive models based on directly measured KOA values of selected chlorobenzenes, polychlorinated biphenyls (PCBs), polychlorinated naphthalenes, polychlorinated dibenzo-p-dioxins/dibenzofurans, polybrominated diphenyl ethers, polycyclic aromatic hydrocarbons, and organochlorine pesticides (OPs). An optimization procedure resulted in two temperature-dependent universal predictive models that explained at least 91 % of the variance of log KOA. Model 1 was the more general of the two models that could be used for all the persistent organic pollutant (POP) classes investigated. Although model 1 performed poorly for select OPs, this was attributed to wide variability in structural types within this subset of POPs and their diversity compared to the other POP classes that were investigated. The exclusion of the structurally complex OP subset resulted in a more precise model, model 5. Intermolecular dispersive interactions (induced dipole-induced dipole forces) between octanol and solute molecules play a decisive role in governing KOA and its temperature dependence. Further investigations are needed to better characterize the steric structures of the POPs under study, especially of OPs.


Subject(s)
Environmental Pollutants/analysis , Models, Theoretical , Air , Forecasting , Octanols/chemistry , Temperature
20.
Chemosphere ; 57(7): 731-8, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15488936

ABSTRACT

Textile dyeing and finishing industry involves considerable amount of water usage as well as polluted and highly colored wastewater discharges. Biological treatability by means of mineralization, nitrification and denitrification of high strength woolen textile dye bathes, first- and second-rinses is presented. COD fractionation study was carried out and kinetic parameters were determined. Biodegradability of organic compounds in highly loaded composite wastewater after segregation and the effluent of applied biological treatment of high strength composite wastewater were measured by determining oxygen consumption rates. The results were used in terms of assessing an alternative method for inert COD fractionation. The study implied that about 80% soluble COD, 50% color and 75% toxicity reduction were possible by single sludge biological processes. Sixteen per cent of total COD was found to be initially inert. Inert fraction was increased to 22% by production of soluble and particulate microbial products through biological treatment.


Subject(s)
Bacterial Physiological Phenomena , Coloring Agents/chemistry , Oxygen Consumption/physiology , Sewage/microbiology , Waste Disposal, Fluid/methods , Wool , Animals , Biodegradation, Environmental , Kinetics , Waste Disposal, Fluid/instrumentation
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