RESUMO
OBJECTIVES: To measure air pollutant concentrations in Chinese restaurant kitchens using different stove types and assess their influence on workers' respiratory health. METHODS: 393 kitchen workers from 53 Chinese restaurants were surveyed over 16 months: 115 workers from 21 restaurants using only electric stoves and 278 workers from 32 restaurants using only gas stoves. Workers were interviewed about their respiratory symptoms and had their lung function tested. Concentrations of nitric oxide (NO), nitrogen dioxide (NO(2)), carbon monoxide (CO), carbon dioxide (CO(2)), methane (CH(4)), non-methane hydrocarbons (NMHC), total volatile organic compounds (TVOC) and fine particulate matter (PM(2.5)) were measured using portable monitors and air-bag sampling. Temperature and noise levels were assessed. RESULTS: Median concentrations of NO, NO(2) and CO were 7.4, 1.5 and 1.6 times higher in gas-fuelled kitchens than in electric ones and average concentrations of PM(2.5) and TVOC were 81% and 78% higher, respectively. Differences were smaller for CH(4) and NMHC. Electricity-run kitchens were 4.5°C cooler and 9 dBA less noisy than gas-fuelled ones. Workers using electric cookers had significantly better lung function than their gas-using counterparts and their mean FEV(1) and FVC values were 5.4% and 3.8% higher, respectively, after adjustment for confounders. Wheeze, phlegm, cough and sore throat were more prevalent in workers using gas. The adjusted OR for having phlegm regularly was significantly higher. CONCLUSIONS: The poorer lung function and higher prevalence of respiratory symptoms among workers in gas-fuelled kitchens compared to those in electricity-powered kitchens may be associated with exposure to higher concentrations of toxic air pollutants generated during gas cooking.
Assuntos
Poluentes Ocupacionais do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Pneumopatias/epidemiologia , Exposição Ocupacional/análise , Material Particulado/análise , Adulto , Poluentes Ocupacionais do Ar/efeitos adversos , Poluentes Ocupacionais do Ar/toxicidade , Poluição do Ar em Ambientes Fechados/efeitos adversos , Povo Asiático/etnologia , Culinária , Volume Expiratório Forçado , Hong Kong/epidemiologia , Utensílios Domésticos , Humanos , Ruído Ocupacional , Material Particulado/toxicidade , Testes de Função Respiratória , Restaurantes , Temperatura , Capacidade VitalRESUMO
In order to screen and identify the source of spilled oils at sea, synchronous fluorescence scans combined with clustering analysis are proposed and applied to different crude oil and weathering crude oil. SFS data of deltal = 25 nm were recorded and dealt with clustering analysis. The cluster results of SFS data in the range of 300 - 500 nm show that the crude oil and the weathering oil could separate completely. And the crude oils from different sea areas, also collected at different time, clustered into different groups, respectively. The results indicate that this method could preliminarily selected, and maybe serves as an assistant method in oil spill identification.
Assuntos
Poluição por Petróleo/análise , Petróleo/análise , Espectrometria de Fluorescência/métodos , Oceanos e MaresRESUMO
The dual objectives of this study are to: (1) examine the relationship between COD and BOD in seawater environment with a rapid but reliable method for the measurement of BOD in seawater, and (2) establish the relationship model between BOD(5) and COD in the firth of Dongbao River to predict the values of BOD(5). The first objective is met by the successful development of a technique utilizing bacteria-immobilized membrane flow cell for biodegradation process, coupled with fibre optic fluorescence detection for oxygen depletion quantitation. The technique has been applied to coastal seawater samples collected in the coastal area of Shenzhen, China. The BOD(5) and COD values for the samples are acquired and the results show that there is no apparent linear relationship existing between BOD(5) and COD in relatively clean seawater samples away from the shore. However, in estuary water samples containing relatively high concentration of sewage contamination, a linear correlation does exist between BOD(5) and COD. The linear relationship between the two parameters allows for the calculation of BOD(5) values based on COD data which can be measured more readily and precisely.
Assuntos
Ecossistema , Oxigênio/metabolismo , Água do Mar/química , China , Oceanos e Mares , Oxigênio/química , Rios , Poluição da ÁguaRESUMO
The dual objectives of this study are to: (1) examine the relationship between COD and BOD in seawater environment with a rapid but reliable method for the measurement of BOD in seawater, and (2) establish the relationship model between BOD(5) and COD in the firth of Dongbao River to predict the values of BOD(5). The first objective is met by the successful development of a technique utilizing bacteria-immobilized membrane flow cell for biodegradation process, coupled with fibre optic fluorescence detection for oxygen depletion quantitation. The technique has been applied to coastal seawater samples collected in the coastal area of Shenzhen, China. The BOD(5) and COD values for the samples are acquired and the results show that there is no apparent linear relationship existing between BOD(5) and COD in relatively clean seawater samples away from the shore. However, in estuary water samples containing relatively high concentration of sewage contamination, a linear correlation does exist between BOD(5) and COD. The linear relationship between the two parameters allows for the calculation of BOD(5) values based on COD data which can be measured more readily and precisely.
Assuntos
Técnicas de Química Analítica/métodos , Oxigênio/análise , Água do Mar/análise , China , Modelos Lineares , Computação Matemática , Oceanos e Mares , Água do Mar/química , Água do Mar/microbiologia , Fatores de Tempo , Poluição da Água/análise , Poluição da Água/estatística & dados numéricosRESUMO
Enhanced anticoagulation and/or even bleeding are often observed when patients on long-term warfarin (WAR) therapy consumed Danshen, a well-known medicinal herb in traditional Chinese medicine (TCM). This study demonstrates that altered WAR metabolism, arising from its interaction with the active components in Danshen, played a significant role in this curative effect. Mass spectrometric techniques including ESI-ITMS (electrospray ionization ion-trap mass spectrometry) and ESI-TOF (time-of-flight)-MS have been developed for the study of such drug-herb interactions. The experimental approach involved a detailed analysis and comparison of WAR metabolites in vivo from blood or urine of rats that had been orally administrated with WAR, either singly or together with the representative bioactive component of Danshen-lipid soluble TIIA (Tanshinon IIA), and a study of the interaction of human serum albumin (HSA), WAR, and water-soluble sodium tanshinone IIA sulfonate (STS) in vitro. Results demonstrate that TIIA accelerates the metabolic rate of WAR, whereas STS displaces WAR from the WAR-HSA complex, resulting in an increase of free WAR concentration in blood. It is suggested that the elevated level and enhanced metabolism of WAR is responsible for the over-anticoagulation effect observed.
Assuntos
Fenantrenos/farmacologia , Albumina Sérica/metabolismo , Espectrometria de Massas por Ionização por Electrospray/métodos , Varfarina/metabolismo , Abietanos , Animais , Ligação Competitiva/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Interações Ervas-Drogas , Humanos , Masculino , Ligação Proteica/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Varfarina/administração & dosagem , Varfarina/farmacocinéticaRESUMO
The extent of organochlorine pesticides (OCPs) contamination in coastal waters around LaiZhou Bay and JiaoZhou Bay in Shandong Peninsula, northern China, was investigated. The areas around the two bays are both densely populated, thrive with intensive agriculture and industrial activities. Multi-techniques including GC-MS, GC-muECD coupled with chemical peak confirmation and strict QC procedures were used for the quantitative determination of 15 OCPs including alpha, beta, gamma and delta isomers of hexachlorocyclohexane (HCH), pentachloronitrobenzene (PCNB), heptachlor, aldrin, endosulfan, p,p'-DDE, dieldrin, endrin, p,p'-DDD, o,p'-DDT, p,p'-DDT and methoxychlor. The survey results show that contaminations by OCP residues remain widespread in the areas, but the averaged concentration levels are all below the regulatory limits, e.g., CMC limits (acute criterion values) specified in US Environmental Protection Agency (USEPA) and China national standards. Average concentration of OCPs in water samples were from undetectable to 3.8 ng l(-1) in LaiZhou Bay and from 0.1 to 3.9 ng l(-1) in JiaoZhou Bay, respectively. A comparison between the current and historical data shows a rapidly decreasing trend of OCPs over the past twenty years in the study areas.
Assuntos
Hidrocarbonetos Clorados/análise , Resíduos de Praguicidas/análise , Água do Mar/química , Poluentes Químicos da Água/análise , China , Cromatografia Gasosa-Espectrometria de Massas/métodosRESUMO
Chromophoric dissolved organic matter (CDOM) represents the fraction of the dissolved organic pool which absorbs light in the visible as well as UV ranges. It could affect the color of the waters. It is necessary to study it during in research on ecosystem, remote sensing of the water color and the cycle of carbon in waters. CDOM can fluoresce when excited, so fluorescence spectrum has been used to study its origin, distribution, and change. In the present article the fluorescence spectrophotometer was used to study the relation between the fluorescence intensity, spectrum area and the concentration of CDOM. When the concentration of CDOM is low (less than 75 mg x L(-1)), there is a better linear relationship (r2 > 0.98) between the fluorescence intensity, the spectrum area and the concentration of CDOM. Meanwhile good linear relations were found between the fluorescence intensity and spectrum area, which showed the same changeable trend of the fluorescence intensity and spectrum area with the concentration change of CDOM. A method was established to quantify the concentration of CDOM in water from different source using the linear relationship between the spectrum area and the concentration. It suits the complicated constituent analysis of CDOM and could really and accurately show the concentration of CDOM in natural water.
Assuntos
Água Doce/química , Compostos Orgânicos/análise , Água do Mar/química , Espectrometria de Fluorescência/métodos , Poluentes Químicos da Água/análise , Monitoramento AmbientalRESUMO
In the present article the principle and advantages of the method to build classification model by partial least squares are briefly introduced. The method was applied to deal with the seawater data obtained from the primary polluted sea area of Jiaozhou bay and Laizhou bay by GC-MS. The classification models have been built for seawater samples from different contaminated areas. The results indicate that PLS is very suitable for dealing with the problems with the data sets that contain many variables and few samples and have serious co-linearity. Accurate classification models can be built by use of PLS to get the classification information of pollution sources from two or many kinds of polluted seawaters data sets from GCC-MS. The cross validation relativities of the model comes to over 0. 91. This result is approving, which can provide a reliable foundation for distinguishing pollution sources correctly. Moreover, compared with the traditional method, the classification figures constructed by model' s yi in the article are more clear and intuitive, and can express the model's discrimination effect better.
Assuntos
Poluição Ambiental , Água do Mar/análise , Poluentes da Água/análise , Monitoramento Ambiental , Cromatografia Gasosa-Espectrometria de Massas , Análise dos Mínimos QuadradosRESUMO
PM2.5 samples were collected at six indoor public places that contained dedicated smoking lounges. Samples were taken in the smoking lounges, at two indoor locations outside of the lounges, and in outdoor air near the venues. Organic carbon (OC), elemental carbon (EC), and non-polar organic compounds including polycyclic aromatic hydrocarbons (PAHs), n-alkanes (n-C16 to n-C40), iso/anteiso-alkanes (C29 to C33), hopanes and phthalate esters (PAEs) were quantified. Average PM2.5 levels of 170.2 ± 85.9 µg/m3 in the lounges exceeded limits of 25 µg/m3 set by World Health Organization (WHO); these levels were 5.4 and 3.9 times higher than those indoors and outdoors, respectively. High ratios of OC to PM2.5, OC to EC, and PAHs diagnostic ratios in the lounges indicated contributions from environmental tobacco smoke (ETS). The maximum carbon number (Cmax) and carbon preference indices (CPI) for n-alkanes showed ETS transport from the enclosed lounges to nearby indoor non-smoking areas. Iso/anteiso-alkanes in the lounges were 876.5 ng/m3, â¼80 times higher than outdoor levels. 17α(H)-21ß(H),30-norhopane and 17α(H)-21ß(H),(22R)-homohopane were much higher in the lounges than outdoor air, but they cannot be directly attributed to ETS. Estimated carcinogenic risks of PAHs in the lounges exceeded the acceptable level of 10- 6.
Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Monitoramento Ambiental/métodos , Material Particulado/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Atmosféricos/efeitos adversos , Poluição do Ar em Ambientes Fechados/efeitos adversos , Alcanos/análise , Carbono/análise , China , Humanos , Tamanho da Partícula , Material Particulado/efeitos adversos , Ácidos Ftálicos/análise , Hidrocarbonetos Policíclicos Aromáticos/efeitos adversos , Medição de Risco , Poluição por Fumaça de Tabaco/efeitos adversos , Poluição por Fumaça de Tabaco/análiseRESUMO
The biodegradation of the organophosphorus insecticide methyl parathion (MP) in aqueous environment by bacteria isolated from river sediment has been studied. Two species of bacteria which show strong MP degradation ability are identified as Shewanella and Vibrio parahaemolyticus. The biodegradation of MP proceeded rapidly with the formation of a series of intermediate products, which were analyzed using a combination of GC/MS and HPLC/ESI-TOFMS techniques. The major products tentatively identified include a series of reduced products of MP. Results demonstrate that the coupling of TOFMS to HPLC enhances further the capability of LC-MS in the identification of polar organic species in complex environmental samples. Degradation pathways leading to the formation of these products are proposed which involves first the reduction of nitro to amino group in MP, followed by combination with some intrinsic matters of bacteria. The mechanism and products from biodegradation are quite different from those of photocatalytic process for which the main intermediates included methyl paraoxon and 4-nitrophenol.
Assuntos
Cromatografia Líquida/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Metil Paration/metabolismo , Shewanella/metabolismo , Espectrometria de Massas por Ionização por Electrospray/métodos , Vibrio parahaemolyticus/metabolismo , Biotransformação , Redes e Vias Metabólicas , Metil Paration/análise , Poluentes Químicos da Água/análiseRESUMO
Glycyrrhizic acid (GA) and licorice flavonoids (LF) are the two classes of bioactive components in licorice with known pharmacological effects. But long-term excessive intake of GA may cause sodium retention and hypertension. In this study, the performance and adsorption characteristics of four widely used macroporous resins for the separation of deglycyrrhizinated, flavonoids enriched licorice has been critically evaluated. The sorption and desorption properties of LF and GA on macroporous resins including XDA-1, LSA-10, D101 and LSA-20 have been compared. The adsorption capacity was found to depend strongly on the pH of the feed solution. XDA-1 offers much higher adsorption capacity for GA and LF than other resins, and its adsorption data fit the best to the Freundlich isotherm. XDA-1 also shows much higher adsorption affinity towards LF than that of GA based on calculated results from the measured adsorption isotherms. Dynamic adsorption and desorption experiments have been carried out on a XDA-1 resin packed column to obtain optimal parameters for separating GA and LF. An enriched LF extract (about 21.9% purity) free of GA, and an enriched GA extract with 66% purity can be separated from crude licorice extract in one run.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Flavonoides/isolamento & purificação , Ácido Glicirrízico/isolamento & purificação , Resinas Sintéticas/química , Adsorção , Concentração de Íons de Hidrogênio , Cinética , TermodinâmicaRESUMO
Five different flavonoids were isolated from licorice after multistep chromatographic fractionation. The aim was to identify and characterize active components in licorice responsible for antibrowning activities and to seek new tyrosinase inhibitors for applications as antibrowning and depigmenting agents in the food and cosmetic industries. The isolated flavonoids were identified as liquiritin, licuraside, isoliquiritin, liquiritigenin (from Glycyrrhiza uralensis Fisch.), and licochalcone A (from Glycyrrhiza inflate Bat.) by UV, MS, (1)H NMR, and (13)C NMR analyses. The inhibitory potencies and capacities of these flavonoids toward monophenolase activity of mushroom tyrosinase were investigated. The IC(50) values of licuraside, isoliquiritin, and licochalcone A for monophenolase activity were 0.072, 0.038, and 0.0258 mM, respectively. A study of the mechanisms of monophenolase inhibition by these flavonoids indicated that they are all competitive inhibitors. Different from the above flavonoids, no inhibitory activity was observed for liquiritin, whereas liquiritigenin activated the monophenolase activity as a cofactor. The inhibitory effect of licuraside, isoliquiritin, and licochalcone A on diphenolase activity with l-DOPA as the substrate was much lower than those with l-tyrosine. Results suggest that licuraside, isoliquiritin, and licochalcone A have the high potential to be further developed into effective antibrowning and depigmenting agents.
Assuntos
Flavonoides/análise , Flavonoides/isolamento & purificação , Glycyrrhiza/química , Monofenol Mono-Oxigenase/metabolismo , Peptídeos/farmacologia , Agaricales/enzimologia , Flavonoides/farmacologia , Espectroscopia de Ressonância Magnética , Oxirredutases/antagonistas & inibidores , Oxirredutases/metabolismoRESUMO
The objective of this study was to develop a rapid, non-destructive and real-time method for the determination of glycyrrhizic acid in glycyrrhiza uralensis fisch. Near infrared spectra (NIR) in the range of 10 000-4 000 cm(-1) were recorded for the glycyrrhiza uralensis fisch containing glycyrrhizic acid in the content of 0.94 %-3.06%. Calibration models were established using the PLS (partial least squares) and PCR (principle component regression) algorithm. Different spectra pretreatments methods were compared. The study showed that PLS model gave better results than PCR with the correlation coefficient 0.958, SEC 0.179 (standard deviation of the calibration sets) and SEP 0.197 (standard deviation of the prediction sets). Results indicate that fiber optic NIR method can be used to on-line control the valid component in Chinese herbs.
Assuntos
Tecnologia de Fibra Óptica/métodos , Glycyrrhiza uralensis/química , Ácido Glicirrízico/análise , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Calibragem , Análise dos Mínimos Quadrados , Análise de Componente Principal , Reprodutibilidade dos TestesRESUMO
The associated industrial and urban developments are located to a large extent along the Laizhou Bay, Bohai Sea coastal and raw sewage is often discharged into near shore waters with little treatment. To find out chemical characteristics and pollution source of the petroleum related contaminations in sediments near the major drainage outfalls located in the coastal, in this study, 10 surface sediment samples were collected during June. Sediment samples were extracted by organic solvents, separated by silica gel column chromatography and the concentrations and the profiles of n-alkane, biomarker and PAH in sediments were analyzed by gas chromatography-mass selective detector (GC-MSD). The use of several molecular markers and related indexes derived for n-alkane and PAHs has been proposed for assessing the relative contributions to the environment of hydrocarbon sources. As a result, n-alkanes reflect that the sea area of paper mill (Station ZZ08) is dominated by vascular plant. DY petroleum oil field and outer shore of the paper mill (Station ZZ02) have some degrees of petroleum related hydrocarbon contamination. Whereas the contamination of the sea area of TH River may be ascribed to different sources such as territorial non-point pollution source, domestic sewages, and stormwater runoff. Judged by their PAH ratios, the sediments near the paper mill (Station ZZ02) and the outer station of the oil field (Staion TH2) were pyrolytic. The estuary of Tiao River including the inner Station THX, TH10 and TH05 are petrogenic. The marine sediment near DY drainage outfall may have a mixture source of PAH both pyrolytic and petrogenic.
Assuntos
Sedimentos Geológicos/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/química , Poluentes Químicos da Água/análise , China , Monitoramento Ambiental , Indústrias , Papel , Petróleo , Água do Mar , Esgotos/químicaRESUMO
Marine invertebrates harbour a wealth of micro-organisms in their bodies. Most of these micro-organisms can catabolize antibiotic compounds as chemical-defence compounds. These compounds not only play an important protective role for their producer and for their hosts, but also have high potential in medicinal applications. In order to discover natural anticancer products, 29 marine bacterial strains have been isolated from the sponge Hymeniacidon perleve, samples of which were collected from the intertidal zone during low tide off Nanji island in Eastern China. By means of a cytotoxicity bioassay, one strain, NJ6-3-1, with significant cytotoxic activity, was selected for culture in a 30-litre fermentation tank. The major cytotoxic compound in the metabolites of NJ6-3-1, separated by means of a bioassay-guided fractionation process, has been identified as norharman (a beta-carboline alkaloid) by electron-impact MS and NMR analyses. Norharman showed cytotoxicity towards both the HeLa cervical-cancer cell line and the BGC-823 stomach-cancer cell line, with an IC(50) of 5 microg/ml. Several methods were used to study the mechanism by which norharman is cytotoxic to HeLa cells. By means of an Acridine Orange/ethidium bromide dual-staining assay, condensation of chromatin was observed. A TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling) assay showed degradation of DNA. Flow-cytometric analysis indicated that norharman could arrest cells at the G(2)/M phase of the cell cycle. These results demonstrate the cytotoxic mechanism of norharman involves the induction of apoptosis in HeLa cells.
Assuntos
Apoptose/efeitos dos fármacos , Harmina/análogos & derivados , Poríferos/microbiologia , Pseudoalteromonas/química , Neoplasias Gástricas/tratamento farmacológico , Neoplasias do Colo do Útero/tratamento farmacológico , Animais , Bioensaio , Carbolinas , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Fermentação , Harmina/farmacologia , Células HeLa , Humanos , Estrutura Molecular , Pseudoalteromonas/isolamento & purificaçãoRESUMO
Polymerization of metallothioneins (MTs) is one of the commonly encountered puzzles in researching the structure and function of metallothioneins. In this work, a method involving SEC coupled with negative ion electrospray ionization mass spectrometry (ESI-MS) detection has been developed for the study of zinc binding MTs' polymerization in tris(hydroxymethyl)-aminomethane (TRIS) acetate buffer at physiological pH. This hyphenated technique allows separating the different polymeric states of MTs by SEC, followed by on-line identification of the individual MT subisoforms in each polymeric peak by ESI-MS detection. Purified MT subisoforms (MT-2d and MT-2a), MT-2d and MT-2a mixture and rabbit liver MT complexes were investigated in the experiments to confirm the results obtained. From the results, both oxidative polymerization and non-oxidative oligomerization were found. The cystein-dependent oxidation results in the tetrameric peak as shown in the chromatograms of oxidized MT-2d, and stable dimeric and monomeric of MT were detected in this peak by MS. For the dimeric and trimeric peaks, different MT subisoforms were detected. In the five major subisoforms detected in rabbit liver MT complexes, MT-2a and MT-2c exist primarily as trimer, while MT-2e, MT-2d and MT-1a exist mainly as dimer. Our results suggest that in the three kinds of polymers, dimer, trimer and tetramer that were found in samples, the tetramer comes from the oxidation of MT molecular; for the dimer and trimer resulting from cystein independent oligomerization, they are closely associated with the charge of subisoform.
RESUMO
The purpose of this study is to develop and apply a mercury analyzer system capable of quantitative analysis of mercury in Traditional Chinese Medicines (TCM) drugs in the concentrations range from ng g(-1) to mg g(-1). No sample pre-treatment was needed and this greatly simplifies the analytical procedure and minimizes potential sources of contamination. The precisions of analyzing solid mercury standard sample and real TCM materials were 2.1% and 2.5-8.2%, respectively; and the recovery based on the analysis of standard reference materials ranged from 95.2% to 105%. The performance of the method has been compared with inductively coupled plasma-mass spectrometry (ICP-MS) technique and excellent agreements were observed between the two methods. The method has been applied to the investigation of Hg content in several TCM drugs containing or not containing cinnabar. Mercury concentration in the same TCM products differs widely with different manufacturers, suggesting that external contamination and the Hg presence in raw herbal materials are the main sources of Hg. In addition, comparison of mercury thermal releasing profiles between TCM drug and cinnabar suggests that mercury conversion from cinnabar to biological matrices-bound Hg could occur because of the aid of other ingredients in the formulated drug.
RESUMO
COD determination based on ozone oxidation of alpha-naphthol combined with UV radiation (UV-O3) has been studied in the present work. Utilizing the phenomenon that luminol can be oxidized by the dissolved ozone to produce luminescence, we have established a new method of utilizing aqueous chemiluminescence to determine COD. The kinetics and mechanism of the ozonation reaction of alpha-naphthol have been investigated in order to gain a better understanding of the general applicability and limitation of the technique. Real world samples were analyzed and the results show that the relative error of COD(FI-CL) measurement for water samples was < 10%. Compared with the results of the conventional potassium permanganate method, the COD values of the FI-CL method are consistently higher (0-20% relative). The higher COD values suggest that the ozone-UV system is a more effective oxidation technique.
Assuntos
Naftóis/química , Oxigênio/análise , Ozônio/química , Raios Ultravioleta , China , Análise de Injeção de Fluxo/métodos , Água Doce/química , Cinética , Medições Luminescentes , Naftóis/efeitos da radiação , Oxirredução , Oxigênio/química , Água do Mar/química , TemperaturaRESUMO
The multi-metal-binding MT fractions in rat tissues after oral intake of cinnabar were characterized by hyphenated size-exclusion chromatography (SEC) and inductively coupled plasma mass spectrometry (ICP-MS). With the increase of both the feeding time and dosage of cinnabar the amounts of Hg-binding MT fractions in rat kidney of groups fed cinnabar increased significantly compared with the control group. Meanwhile, more Cu-binding MT were synthesized in the rat kidney, which confirmed the manipulating effect of MT in the homeostasis of Cu for detoxification of nephritic mercury. Although the Hg-binding MT fractions in rat liver of all cinnabar groups were almost independent of cinnabar dosage (2.5-5.0 g kg(-1) bw) and feeding time (2-4 weeks), the amount was much higher than that of the control group. The amounts of Hg-MT in other rat tissues of the cinnabar groups and the control group were compared and their significance is discussed.