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1.
Active moss biomonitoring using the species Sphagnum girgensohnii was tested at a strongly polluted site in Romania (Baia Mare) according to a novel sampling design. Nine moss transplants from each of the two background areas (Dubna, Russia and Vitosha Mountain, Bulgaria) were deployed in parallel on balconies about 24 m above street level for 4 months. The samples were analyzed for 36 elements using instrumental neutron activation analysis (INAA). Based on the results obtained the sampling variability is discussed in relation to the analytical variability, and the relative uptake of the different elements is assessed. The moss-bags using Sphagnum girgensohnii demonstrate a high or a very high relative uptake for a majority of the 36 investigated elements, but the values depend on the initial element concentration in the moss. Moss leaves analyzed separately showed somewhat higher levels than stems for many elements. Practical considerations however still speak in favor of using the whole moss for transplants.  相似文献   

2.
A peat core from a Swiss bog represents 2110 14C years of peat accumulation and provides a continuous record of atmospheric rare earth element (REE) deposition. This is the first study providing a time-series of all REE originating from the atmosphere. Concentrations of the 14 REE (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu) were determined using inductively coupled plasma-mass spectrometry (ICP-MS) after dissolution of 200 mg aliquots of age-dated peat samples with 3 ml HNO3 and 0.1 ml HBF4 at 240 degrees C in a microwave autoclave. Strict quality control schemes were applied to ensure the accuracy of the applied analytical methodology. Previous analyses of selected REE by instrumental neutron activation analysis (INAA) in the same set of peat samples revealed that INAA frequently under- or overestimated REE concentrations in a systematic manner. Concentration profiles obtained for all REE were almost identical, except for Ce and Eu. Calculation of enrichment factors (EF) revealed a distinct depletion of heavy REE relative to light REE in peat samples since the beginning of the 19th century which marks the onset of the Industrial Revolution in Europe, suggesting a pronounced influence by anthropogenic activities. Enrichments of REE calculated using Sc as a reference element exceeded unity, relative to the Upper Continental Crust. Overall, EF in all peat samples ranged from 1.96 for Sm to 2.34 for Gd, with considerably lower EF for Ce (1.82) and Eu (1.44), respectively. A significant enrichment of all REE which may have been caused by military activities, was observed in the peat sample dating from World War II (1944); this exceptional sample, however, is not enriched in Ce. The concentration profiles of REE were similar but not identical to those of other lithogenic, conservative reference elements such as Sc, Y, Al, Zr and Ti. While it has been suggested that individual REE concentrations or the sum of REE can be used as a reference parameter to calculate crustal EF in environmental samples the data presented here indicates that anthropogenic emissions of REE cannot simply be ignored.  相似文献   

3.
Mosses are used as biomonitors on a regular basis to study trends in the atmospheric deposition of trace elements in Norway. In this paper the analytical scheme used so far, based on a combination of instrumental neutron activation analysis and atomic absorption spectrometry (INAA/AAS) is compared with inductively coupled plasma emission spectrometry (ICP-ES) and inductively coupled plasma mass spectrometry (ICP-MS). ICP-ES provided satisfactory data for nearly 20 elements, but detection limits were inadequate for some elements of importance. For ICP-MS quantitative data were obtained for 33 elements including the heavy metals of key interest in air pollution studies. In most cases where comparison was possible the ICP-MS data compared favourably with data obtained by the reference scheme or by ICP-ES. On the basis of this study ICP-MS is considered to be an equivalent alternative to INAA/AAS in multielement studies using mosses as biomonitors. In addition ICP-MS offers some promise for the study of elements such as Be, Ga, Mo, Te, Tl, and Bi, for which very little information exists regarding their behaviour as air pollutants.  相似文献   

4.
Platinum, gold and calcium concentrations of 20 samples of airborne dust collected at two sampling sites between 1995 and 1997 in the city of Copenhagen, which suffers from heavy traffic, were determined by instrumental neutron activation analysis (INAA). INAA of platinum using the 199Au daughter of 199Pt was performed. Two interferences on the INAA of platinum were removed by calculations. The spectral interference on 199Au from the 47Sc daughter of 47Ca was removed by separating the 157-161 keV doublet peak into its components by calculating the counts due to 47Sc from the counts of the parent 47Ca. The contribution of 197Au to 199Au by two neutron absorption was corrected for using the ratio 198Au/199Au in a pure Au standard. From the INAA results, high platinum concentrations are present in air in the range 0.25-2.74 ng m-3 and gold concentrations in the range 0.10-1.96 ng m-3.  相似文献   

5.
Former battery factories have created environmental and health problems for years and the exposure to lead in surface soils has been underestimated. Nonetheless, the identification of lead contamination and its spatial distribution is crucial. The determination of heavy metals in soils can be performed using inductively coupled plasma mass spectrometry (ICP-MS). However, alternative techniques such as X-ray fluorescence (XRF) have been used lately in environmental studies since measurements can be taken in the field in a prompt manner, despite its lower accuracy. In this study, a former battery factory site in Monterrey, Mexico, has been studied in order to detect lead contamination. Soil samples were assessed for contamination by using an analytical hybrid method that comprises both analytical techniques, namely, ICP-MS and XRF. Samples were taken in 215 locations and, after a simple homogenization process, they were analyzed by using a portable XRF device. Within those 215 sampling points, 25 samples were analyzed concurrently by using ICP-MS according to international sampling guidelines. Results obtained were adjusted in order to define an analytical hybrid method, which encompasses the advantages of each technique. An improved characterization was achieved by using the proposed analytical hybrid method since maps of lead distribution and calculated areas of concern showed better predictability. The combination of spectroscopic techniques is of great applicability for environmental agencies and decision makers.  相似文献   

6.
地表水监测误差分析与对策   总被引:1,自引:0,他引:1  
分析和探讨了地表水环境监测过程中存在的误差。在13家监测站同步采样、同步分析的基础上,筛选出地表水监测实验室间比对结果偏差较大的石油类、挥发酚、氨氮、五日生化需氧量、化学需氧量、高锰酸盐指数和总磷等7个监测指标。从方法误差、仪器误差、试剂误差、操作误差、环境误差、过失误差和质控选择不当造成的误差等各方面探讨误差成因。根据实样测定结果,提出合理选择并统一分析方法、增加平行测定次数、加强质控措施和修改允许相对偏差等切实可行的对策和措施,为地表水监测和水环境管理提供技术依据。  相似文献   

7.
Estimation of essential and toxic element intakes is crucial to evaluate the risks of deficiency or toxicity. The purpose of this study was to investigate and also to compare the dietary intakes of zinc (Zn) and copper (Cu) by adults living in Shiraz, Iran, determined by two procedures: duplicate portion sampling of 21 hospital meals combined with either instrumental analysis (voltammetric measurement) or the use of food composition tables (FCTs). The level of exposure to lead (Pb) and cadmium (Cd) was evaluated as well. The daily Zn intakes of both methods were not significantly different and were higher than the RDA values except the value measured by the instrumental analysis which was lower than the RDA established for a male adult. Daily intake of Cu determined by instrumental analysis was significantly lower and closer to RDA for adults compared with the value estimated by FCTs. The dietary intakes of Pb and Cd were 313 and 61 % of the respective provisional tolerable weekly intakes (PTWIs), respectively. The accuracy of two methods used for estimation of Zn intake was similar. In the case of Cu, the use of FCTs, in which the influence of environmental conditions and dietary habits of meal preparation is not taken into account, overestimated dietary intake. The risk of zinc deficiency was found in adult males. Moreover, the estimated intake of Pb, but not Cd, could be a cause of concern for Shiraz population. Thus, conducting regular periodic studies to assess the dietary intake of mentioned elements are recommended.  相似文献   

8.
Advances in instrumentation are making Raman spectroscopy the tool of choice for an increasing number of chemical applications. For example, many recalcitrant industrial process monitoring problems have been solved in recent years with in-line Raman spectrometers. Raman is attractive for these applications for many reasons, including remote non-invasive sampling, minimal sample preparation and tolerance of water. To a lesser extent, Raman spectroscopy is beginning to play a significant role in environmental analysis for the same reasons. At present, the environmental applications typically apply only to the most contaminated situations due to the still relatively high limits of detection. However, some emerging sampling technologies hold out the promise that Raman may soon be more widely applicable to the analytical chemistry of potable water. Herein we discuss these recent advances, summarize some examples of environmental applications to aqueous systems and suggest avenues of future developments that we expect to be most useful for potable water analysis. Also, a simplified, but detailed, theory of normal Raman scattering is presented. While resonance-enhanced Raman spectroscopy, surface-enhanced Raman spectroscopy and non-linear Raman techniques are briefly discussed, their theories and instrumental configurations are not addressed. Also, this article deals primarily with the modern dispersive Raman experiment (as opposed to the Fourier transform Raman experiment), because it seems most suited for potable water analysis. The goal of this article is to give the environmental scientist with no specialized knowledge of the topic just enough theory and background to evaluate the utility of this rapidly developing analytical tool.  相似文献   

9.
煤气化过程中气态污染物采样分析的研究进展   总被引:1,自引:0,他引:1  
通过考察气态污染物采样方法的基本原理,对比分析国内外常压采样系统和加压采样系统的设计特征,选择煤气化过程中5种常见气态污染物为分析对象,列举常用的化学分析法和仪器分析法,为加压气化装置采样系统的设计提供参考材料和建议,归纳了一些有助于提高气态污染物检测数据可靠性的措施,希望能为煤气化过程中(特别是加压煤气化过程中)气态污染物采样系统的设计提供思路和借鉴。  相似文献   

10.
Water-soluble inorganic ions in aerosol samples have been studied. The sample collection took place during summer in 2003 at a European background site which is operating within the framework of the European Monitoring and Evaluation Program. Gent type PM10 stacked filter unit (SFU) samplers were operated in parallel on a day and night basis to collect particles in separate coarse (2.0-10 microm) and fine (<2.0 microm) size fractions. Particulate masses were measured gravimetrically; the filters from one of the SFU samplers were analyzed by particle-induced X-ray emission spectrometry (PIXE) and instrumental neutron activation analysis (INAA). Filters from the other SFU sampler were analyzed by ion chromatography (IC) for major inorganic anions (MSA-, NO2(-), NO3(-), Cl-, Br-, SO4(2-), oxalate) and cations (Na+, K+, NH4(+), Mg2+, Ca2+). The water-soluble inorganic ions measured were responsible for 44% and 16% of the total fine and coarse particulate mass, respectively. In the fine size fraction, the main ionic components were SO4(2-) and NH4(+) accounting for about 90% of fine ionic mass. In the coarse fraction the main ionic components were Ca2+ and NO3(-), followed by SO4(2-). Significant day and night difference in the mass concentrations was observed only for fine NO3(-). The molar ratios of fine NH4(+) to SO4(2-) indicated their complete neutralization to (NH4)2SO4. According to the cation-to-anion ratios the coarse particles were alkaline, while the fine particles were slightly acidic or neutral. By comparing the corresponding concentrations obtained from PIXE/INAA and IC, we determined the water-extractable part of the individual species. We also investigated the effect of long-range transported air masses on the local air concentrations, and we found that the air quality of this background monitoring station was affected by regional pollution sources.  相似文献   

11.
A method is presented for the determination of isocyanic acid (ICA), HNCO, in air samples as a di-n-butylamine (DBA) derivative. The method is based on sampling in midget impinger flasks containing 10 ml of 0.01 mol l-1 DBA in toluene. Quantification was made using liquid chromatography (LC) and electrospray mass spectrometry (MS) monitoring positive ions. The instrumental detection limit for the LC-MS was 10 fmol of ICA-DBA. ICA was generated by thermal decomposition of urea. A standard solution containing the DBA derivatives of ICA was prepared by collecting the emitted ICA in an impinger flask containing DBA. ICA in the reference solution was characterised by LC and time-of-flight (TOF) MS and quantified by LC chemiluminescent nitrogen detection (LC-CLND). The instrumental detection limit for the LC-CLND was 1 ng of nitrogen. ICA was emitted during thermal degradation of PFU resins and polyurethane (PUR) lacquers, from car metal sheets. ICA was the most dominant isocyanate and in PUR coating up to 8% of the total weight was emitted as ICA and for PFU resins up to 14% was emitted as ICA. When air samples were collected in an iron foundry during casting in sand moulds with furan resins, concentrations of ICA in the range 50-700 micrograms m-3 were found in the working atmosphere.  相似文献   

12.
A method for determination of technical grade isocyanates used in the production of polyurethane (PUR) is presented. The isocyanates in technical grade products were characterised as di-n-butylamine (DBA) derivatives using LC-MS and LC-chemiluminescent nitrogen detection (CLND) and the total isocyanate content was compared to a titration assay. For collection of isocyanates in air, an impinger-filter sampling technique with DBA as derivatisation reagent was used. Characterised DBA and nonadeuterium labelled DBA derivatives of isocyanates in technical products were used as calibration standards and internal standards, respectively, in the analysis of air samples. Three workplaces were studied where PUR products were produced either by spraying or by moulding. In both technical products and in air samples, a number of monomeric, oligomeric and prepolymeric isocyanates of e.g. methylenebisphenyl diisocyanate (MDI) and hexamethylene diisocyanate (HDI) were characterised. Several of these have not previously been described in workplace atmospheres. In the technical isocyanate products, between 69 and 102% of the NCO content determined by titration was accounted for by LC-CLND. Quantifications of a wide range of isocyanates in air samples were performed with correlation coefficients in the range 0.988-0.999 (n= 8) and the instrumental detection limits were 0.7-25 pg. At the two workplaces where MDI- and HDI isocyanurate-based products were sprayed, the isocyanate composition in the air reflected the composition in the technical product. At the workplace where a MDI-based product was used in a moulding process, only the monomeric isocyanates were found in the air. The advantage of using characterised technical grade isocyanates as analytical standards was clearly demonstrated and the possibility of using index compounds when monitoring isocyanate exposure is discussed.  相似文献   

13.
通过考察气态污染物采样方法的基本原理,对比分析国内外常压采样系统和加压采样系统的设计特征,选择煤气化过程中5种常见气态污染物为分析对象,列举常用的化学分析法和仪器分析法,为加压气化装置采样系统的设计提供参考材料和建议,归纳了一些有助于提高气态污染物检测数据可靠性的措施,希望能为煤气化过程中(特别是加压煤气化过程中)气态污染物采样系统的设计提供思路和借鉴。  相似文献   

14.
Pollution studies of air and water samples have been greatly enhanced by the use of chromatographic techniques. The selection of the proper detectors coupled with the various column types and substrates have broadened the capabilities of environmental analyses. Proper care in sampling protocols and sample treatment has steadily improved the sensitivity of these measurements. The recommended methods for air, wastewater, drinking water and solid waste samples all utilize some type of chromatographic analysis for the determination of organic contaminants. Three complimentary techniques: i.e., headspace sampling (dynamic and static methods), microextractions (liquid-liquid and/or liquid-solid) and solid-phase extractions have expanded the capabilities of such studies to permit the analytical chemist to perform fast in-the-field monitoring, concentrate low levels of analytes and determine solubilities of toxic substances. A discussion of other environmental areas which should be studied, along with the changes and/or modifications in analytical technology which should be investigated, will be presented.Plenary speaker.  相似文献   

15.
The growing interest in the environmental occurrence of veterinary and human pharmaceuticals is essentially due to their possible health implications to humans and ecosystem. This study assesses the occurrence of human pharmaceuticals in a Malaysian tropical aquatic environment taking a chemometric approach using cluster analysis, discriminant analysis and principal component analysis. Water samples were collected from seven sampling stations along the heavily populated Langat River basin on the west coast of peninsular Malaysia and its main tributaries. Water samples were extracted using solid-phase extraction and analyzed using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) for 18 pharmaceuticals and one metabolite, which cover a range of six therapeutic classes widely consumed in Malaysia. Cluster analysis was applied to group both pharmaceutical pollutants and sampling stations. Cluster analysis successfully clustered sampling stations and pollutants into three major clusters. Discriminant analysis was applied to identify those pollutants which had a significant impact in the definition of clusters. Finally, principal component analysis using a three-component model determined the constitution and data variance explained by each of the three main principal components.  相似文献   

16.
This paper reports the results of a pesticide monitoring survey on wine grapes from the 2008–2010 vintage from vineyards grown according to integrated pest management strategies. A multi-residue gas chromatography-mass spectrometry method in electron ionization and chemical ionization mode has been used for the determination of 30 pesticides in wine samples. The analytical method showed good recoveries and allowed a good separation of the selected pesticides. Repeatability and intermediate precision showed good results with CV?<?20 %. The instrumental method limits of determination (LOD) and of quantification (LOQ) were below the maximum residue levels set in wine. The analysis of the wines showed that pesticide residues were below the instrumental LOQ, and most of them were undetectable (<LOD). Only the 38 % of the pesticide applied has been detected in at least one cultivar. Metalaxil, myclobutanil, and penconazole were the pesticides most frequently found, while carignano and vermentino were the cultivars with the higher number of residues.  相似文献   

17.
Depleted uranium (DU) weapons testing programmes have been conducted at two locations within the UK. An investigation was therefore carried out to assess the extent of any environmental contamination arising from these test programmes using both alpha spectrometry and mass spectrometry techniques. Uranium isotopic signatures indicative of DU contamination were observed in soil, plant and earthworm samples collected in the immediate vicinity of test firing points and targets, but contamination was found to be localised to these areas. This paper demonstrates the superiority of the (235)U : (238)U ratio over the (234)U : (238)U ratio for identifying and quantifying DU contamination in environmental samples, and also describes the respective circumstances under which alpha spectrometry or mass spectrometry may be the more appropriate analytical tool.  相似文献   

18.
During a monitoring campaign concentrations of volatile organic compounds (VOCs) were measured in indoor air of 79 dwellings where occupants had not complained about health problems or unpleasant odour. Parameters monitored were the individual concentration of 68 VOCs and the total concentration of all VOCs inside the room. VOCs adsorbed by Tenax TA were then analysed by means of thermal desorption, gas chromatography and mass spectrometry. The analytical procedure and quantification was done according to the recommendation of the ECA-IAQ Working Group 13 which gave a definition of the total volatile organic compound (TVOC) concentration. Using this recommendation TVOC-concentrations ranged between 33 and 1600 microg m(-3) with a median of 289 microg m(-3). Compounds found in every sample and with the highest concentrations were 2-propanol, alpha-pinene and toluene. Save for a few samples, all concentrations measured have been a factor 2 to 10 lower, compared to data from similar studies. Only a few terpenes and aldehydes were found exceeding published reference data or odour threshold concentrations. However, it has been found that sampling and analysing methods do have a considerable impact on the results, making direct comparisons of studies somewhat questionable. 47% of all samples revealed concentrations exceeding the threshold value of 300 microg TVOC m(-3) set by the German Federal Environmental Agency as a target for indoor air quality. Using the TVOC concentration as defined in the ECA-IAQ methodology is instrumental in assessing exposure to VOCs and identifying sources of VOCs. The background concentrations determined in this study can be used to discuss and interpret target values for individual and total volatile organic compounds in indoor air.  相似文献   

19.
An analytical method for ethylene glycol and propylene glycols has been developed for measuring airborne levels of these chemicals in non-occupational environments such as residences and office buildings. The analytes were collected on charcoal tubes, solvent extracted, and analyzed by gas chromatography-mass spectrometry using a positive chemical ionization technique. The method had a method detection limit of 0.07 microg m(-3) for ethylene glycol and 0.03 microg m(-3) for 1,2- and 1,3-propylene glycols, respectively, based on a 1.44 m3 sampling volume. Indoor air samples of several residential homes and other indoor environments have been analyzed. The median concentrations of ethylene glycol and 1,2-propylene glycol in nine residential indoor air samples were 53 microg m(-3) and 13 microg m(-3) respectively with maximum values of 223 microg m(-3) and 25 microg m(-3) detected for ethylene glycol and 1,2-propylene glycol respectively. The concentrations of these two chemicals in one office and two laboratories were at low microg m(-3) levels. The maximum concentration of 1,3-propylene glycol detected in indoor air was 0.1 microg m(-3).  相似文献   

20.
An air sampling method for the determination of isocyanates, aminoisocyanates and amines formed during the thermal degradation of polyurethane (PUR) is presented. The method is based on the collection of air samples using impinger flasks containing di-n-butylamine (DBA) in toluene with a glass fibre filter in series. Isocyanates are derivatized with DBA to urea derivatives, and amines are derivatized in a subsequent work-up procedure with ethyl chloroformate (ET) to carbamate esters. Amine, aminoisocyanate and isocyanate derivatives were characterized using liquid chromatography-time of flight mass spectrometry (LC-TOFMS) and liquid chromatography-chemiluminescent nitrogen detection (LC-CLND). Quantification was performed by LC-MS, monitoring molecular ions [MH]+ in the electrospray mode. The instrumental detection limits for amines, aminoisocyanates and isocyanates were in the ranges 30-40, 2-3 and 3-70 fmol, respectively. Thermal degradation products of PUR were observed in high concentrations during welding in district heating pipes and PUR-coated metal sheets. Eleven isocyanates, three amines and five aminoisocyanates were identified. The concentrations of isocyanates, aminoisocyanates and amines in samples collected in the smoke close to the welding spot were in the ranges 150-650, 4-290 and 1-70 ppb, respectively. In samples collected in the breathing zone, isocyanates and aminoisocyanates were observed in the ranges 9-120 and 4-19 ppb, respectively. The compounds were present in both gas and particle phases. Volatile compounds dominated in the gas phase, whereas less volatile compounds dominated in the particle phase. The method presented makes it possible to sample and determine amines and aminoisocyanates, in addition to isocyanates. The need to monitor these compounds is clearly illustrated by the high concentrations found during the thermal degradation of PUR.  相似文献   

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