摘要:

1Air analysisThis section of the update covers the analysis of aerosols, particulates and gases by analytical atomic spectrometry. Papers published in the last 12 months are summarized inTable 1. Noteworthy areas of research and development are highlighted below. There were a number of useful reviews: development of mass spectrometry for the real time interrogation of individual particles;1,2microprobe XRF for the characterization of atmospheric particles;3bulk analysis using TXRF4and AA/ICP techniques;5and a compendium of techniques for both surface and bulk analysis.6Summary of analyses of air and particulatesElementMatrixTechnique; atomization;presentation*Sample treatment/commentsRef.*Hy indicates hydride and S, L, G and Sl signify solid, liquid, gaseous or slurry sample introduction, respectively. Other abbreviations are listed elsewhere.AsAirborne particulate matterMS;ICP;SMixed acid digestion (HNO3–H2O2–HF) in high-pressure bombs utilized. CRMs used for method validation. Isobaric overlap noted if chlorinated acids used18AsWorkplace airAE;ICP;GBubbler sampler system used with concentrated HNO3in front two flasks and with an alkali end-trap. Alkali and alkaline-earth metals found to interfere at concentrations >0.1%41AsAirborne dustAE;ICP;SClosed vessel microwave assisted dissolution utilized19BrAerosol samplesPIXE;—;SBr impurity contained in Nucleopore™filters used as an in-sample internal standard42CGaseousAMS;—;SMethod for the preparation of carbonyl compounds for14C analysis described. The method involved sampling air onto DNPH coated silica gel cartridges and extracting with CH3CN with purification over activated silica gel to remove excess DNPH and non-target compounds43CGaseousAMS;—;—Approaches for the measurement of14C in µg carbon samples by optimizing sample preparation, instrument operation and data evaluation described44ClGaseousAE;GD;GUse of gas-jet glow discharge AES investigated as a means of destroying gaseous pollutants. CCl4used as a model contaminant. Extent of decomposition under optimized conditions was found to be >96%. Potential of using Cl (I) 452.6 nm to monitor decomposition on a real time basis discussed45CdAirborne dustAA;ETA, F;SSpeciation carried out using an operationally defined sequential extraction procedure. Method validation carried out using synthetic mixtures of Cd salts. Extraction protocol applied to dust samples collected using an electrostatic precipitator at a coal powered electricity generation station46CrAirborne particulate matterMS;ICP;SMixed acid digestion in high pressure bombs developed and optimized (HNO3–HClO4plus addition of HF in a second step). LOD <10 ng g−1when analysed using HR-ICP-MS. Results obtained using LA-ICP-MS compared well with data obtained using dissolution procedure (LOD 0.05 µg per filter)47HgGaseousAE;—;GPhoto fragmentation emission spectroscopic technique described for the gas phase detection of HgCl2, Hg(CH3)Cl and HgI248HgGaseousAF;F;GVapour in humid air trapped onto Au impregnated silica and desorbed from this trap, concentrated on a fixed Au impregnated sand trap prior to analysis. Method applied to the measurement of exhaled air. RSD 8.7–10.7% at 10–250 pg (LOD 0.6 pg)49HgGaseousMS;ICP;GCryogenic sampling compared to Au amalgamation sampling. Levels found in the Amazon basin ranged from 2 to 20 ng m−3. Mainly found in metallic form36HgUrban particulateAF;—;SParticulate trapped on a quartz fibre filter within a quartz trap followed by heating to release Hg and concentrated on an analytical Au trap. Measured total particulate Hg concentrations in the range 3–91 pg m−350IAmbient airMS;ICP;G129I measured using precipitation techniques with on-line analysis (decomposition of PdI2, I2swept into plasma).129Xe can interfere with the analysis. Application used non-proliferation monitoring programs (LOD <50 fg)22InUrban dustAF;ETA;SLaser excited AF system with platform atomization within graphite furnace gave best performance. Absolute LOD 1 fg (10 µl sample injection). RSD 4.1% at 10 ng ml−1(n= 10)51MnAirAA;ETA;SFilter samples digested in concentrated HNO3for 1–2 h with measurement precision typically better than 3% (LOD 0.06 µg per filter)52NiAirborne factory dustAA;—;SSoluble Ni determined after extraction using ammonium citrate (buffered at pH 4). Insoluble Ni determined following dissolution using HNO3–HClO4–H2SO4. Dust studied using XRD and SEM. Implications of findings regarding occupational exposure discussed33PbUltrafine aerosolsAE;F;S AF;LIPS;SDifferential mobility particle sizer used to segregate particle sizes. Air–acetylene flame and LIP used as atomization sources. AES system used with a CCD detector or a laser excited AFS system (LOD 55–130 ng m−3for particles in the range 44–300 nm)53PbAirborne particulate matterXRF;—;SAnalysis using a thin film approach carried out. Italian city of Lecce monitored54PbAirborne particulate matterMS;ICP;SIsotopic measurements performed for source apportionment studies. Unequivocal evidence that ore derived Pb from local mining sources had become the dominant source in dust fallout samples26PbDust particlesXRF;—;SPortable system evaluated for use in paint stripping and removal abatement programs. (LOD ranged from 0.01 to 0.1% (in the solid) for elements withZ>50 using 15 s measurement interval)55PbAirborne particulate matterXRF;—;S AA;F;SFilter samples analysed following dissolution with a mixture of HNO3–H2O2. Good agreement obtained between methods56PbAirborne particulate matterXRF;—;SIn-field evaluation of portable instrument data from TSP and PM10samples compared with that from ICP-AES following dissolution. Results showed feasibility of portable systems to provide accurate air data20PdAirborne particulate matterAA;ETA;SElectrodeposition on graphite tube prior to insertion of tube into furnace described57PtAirborne particulate matterAA;ETA;SSee Pd,ref. 5757SAirborne particulate matterXPS;—;S XAS;—;SComparison made between the two techniques for interrogating particle surfaces. Concluded that XAS was more suitable for the chemical state analysis of S within aerosol samples40SAirborne particulate matterAE;—;GAir sampled onto glass fibre filters and subsequently extracted with CH2Cl2. Following clean-up on deactivated silica gel columns, S containing PAHs analysed using a GC-AES system58SbAirborne particulateAF;Ar–H2;SImproved hydride generation procedure developed (stibine generated at 70 °C; cooled phase separator and drying tube used; auxiliary stream of H2introduced to support flame). Calibration linear to 2.7 mg l−1, RSD 1.4% at 8 µg l−1and 0.6% at 100 µg l−1. NIST SRM 1648 used as QC material. Bilbao air found to contain 13.2 ± 0.3 ng m−3(LOD 0.3 µg l−1)59SeGaseousMS;ICP;GCryogenic sampling compared to Au amalgamation sampling. Levels found in the Amazon basin ranged from 10–100 pg m−3. Cryogenic sampling demonstrated that Se present in biogenic forms such as Me2Se, Me2Se2and Me2SeO36SiAirborne particulate matterMS;ICP;S XRF;—;SLA performed on samples collected onto PTFE filters. NIST 1648 urban particulate matter used to prepare calibration filters. Good agreement with data from XRF25VAirborne particulate matterMS; ICP;SMixed acid digestion (HNO3–H2O2–HF) in high-pressure bombs utilized. CRMs used for method validation. Isobaric overlap noted if chlorinated acids used18VariousAtmospheric particlesXRF;—;SAerosols collected on PTFE filters within virtual impactors in a study of air mass movements in Western Scandinavia60VariousProcess gasesAA;ETA;GModified system used to determine metal traces in gaseous HCl, Cl2and trichloroborane. Calibration carried out using standard addition of both gaseous samples and standard solutions61VariousStack gasAE;ICP;SCorrection of spectral interference arising from CN emissions in an on-line air-Ar ICP-AES system. Correction protocol involved the measurement of CN emission at 359.255 nm (introduction of known amounts of CO2into the plasma prior to analysis in order to derive a correction factor)8VariousLandfill and fermentation gasesMS;ICP;GIon trap EI-MS-MS and ICP-MS coupled to the same GC to provide qualitative molecular (qualitative) and elemental data (quantitative) on volatile Bi, Sb and Sn compounds35VariousAirborne particulate matterAA;ETA;SParticulate matter collected on phenylpolypropylene filter dissolved in IBMK to form a colloidal solution. 10 µl aliquots injected into furnace. RSD in the range 2–8% (LODs 0.05, 1, 1, 2 and 5 ng m−3for Cd, Cr, Cu, Pb and Ni)62VariousAerosol samplesAA;—;SSize fractionated particulate matter collected onto filters in a cascade impactor. Three stage operationally defined sequential extraction procedure carried out to study the fractionation of elements as a function of particle size63VariousParticulate and vapour phase samples—;—;—Patent application for a sampling system to collect mixed phased samples from gases that cannot be hydrolysed. Twin filter system with first filter at ambient temperature to collect particulate phase and second filter at temperature below ambient to remove vapour phase38VariousAtmospheric dust samplesXRF;—;SThin film calibration standards and samples prepared by dispersing powdered standards onto hydrophilized PTFE filters and drying under an IR lamp. Standards prepared by impregnating activated C powders with standard elemental solutions64VariousCigarette smokeAE; ICP;S AA;ETA;SSmoke condensate collected by electrostatic precipitation. Condensate extracted from collection tubes with methanol. Evaporation and subsequent dissolution carried out in a microwave oven65VariousAirborne particulate matterMS;ICP;S XRF;—;SNIST CRM 1648 Urban Particulate Matter used to prepare calibration filters for laser ablation studies. Prepared filters characterized by LA-ICP-MS, XRF and ICP-MS following dissolution66VariousAirborne particulate matterAE;ICP;SDust discharges from coal burning electricity generating plant analysed for Be, Cd, Co, Cr, Cu, Ni and Pb67VariousAirborne particulate matterEPMA;—;SElectron probe X‐ray microanalysis used for the assessment of homogeneity IAEA candidate reference materials (coarse and fine fraction urban dusts)68VariousAtmospheric aerosolsXRF;—;SSynchrotron excitation used for elemental analysis. Variability in measurement results attributed to the change in the intensity of excited synchronous radiation. Impurity levels in the filter media determined the LODs69VariousAtmospheric aerosolsPIXE;—;SParticulates from atmosphere around a steel smelter collected on a time resolved streaker sampler. Counting period of 5 min used (LODs ranging from 2 ng m−3for Cu to 0.1 µg m−3for K)70VariousAir particlesXRF;—;STime resolved samples collected on a streaker sampler. Performance of capillary optics EDXRF system compared to PIXE for the analysis of urban aerosols71VariousAir particlesXRF;—;SReceptor model source apportionment study undertaken as part of a pollution control strategy using fine, coarse and TSP samples72VariousAtmospheric aerosolsXRF;—;SSynchrotron radiation source used in the analysis of Siberian aerosols73VariousAir particlesXRF;—;SInterlaboratory trial compared synchrotron radiation source data obtained using XRF with that obtained using INAA, AA and AES techniques74VariousAir particlesXRF;—;SSynchrotron source technique used to study the impact of anthropogenic aerosols75VariousCar exhaust emissionsXRF;—;SEmission rates determined over different driving cycles. Elemental determinations suggest that 10–30% of samples are composed of metals, S and Si compounds76VariousUrban aerosolsPIXE;—;S INAA;—;S XRF;—;SAnalytical quality assessment of data carried out through exchanging filter samples and by the analysis of a set of multiple filters collected in parallel at one site27VariousAirAE;—;GF (685.604 nm), Cl (837.594 nm), S (921.29 nm) and C (833.515 nm) determined by time resolved LIPS using SF6and a number of fluorocarbons as surrogate analytes (LODs 20, 90, 1500 and 36 mg l−1respectively)12VariousVolatile metal and metalloidsMS;ICP;GAir samples collected on a cryotrap (silanized wool, −175 °C). Analytes flash desorbed onto an analytical column (10% of Supelco SP2100 on Chromosorb W HP (60–80 mesh) immersed in liquid N2. Analytical column gently heated and the analytes flushed into the plasma using a stream of He. O2makeup used to minimize C-containing species and Xe used as an internal standard (LODs <1 pg for alkylated species)34VariousUrban aerosolsPIXE;—;SDetermination of elements collected on Whatman 41 filters. Effects of filter thickness and penetration of particles into the filter on beam attenuation and X‐ray emission intensity studied77VariousUrban aerosolsMS;—;SReview of methods currently used to make MS techniques into a tool for particle size determination presented1VariousUrban aerosolsMS;—;SReview of TOF methods for real time analysis of individual particles2VariousStack gasAE;ICP;GEffect of water vapour and alkali metal salts upon online air plasma system studied. Best LODS obtained for 50% Ar–50% air mixed plasma9VariousUrban aerosols—;—;—Review of techniques for the topochemical analysis of airborne particles6VariousPower plant emissionsMS;ICP;SMicrowave assisted dissolution procedure developed (HNO3–HCl–HF) for the digestion of filter samples. NIST CRM 1633a and 1648 used in method development. Results for real samples compared with data obtained using INAA, GFAAS and HGAAS78VariousAtmospheric dustAE;ICP;SWater and acid soluble (0.1 mHCl) components measured16VariousAir particlesAE;ICP;S MS;ICP;SParticulate matter collected on glass fibre filter from a beta gauge monitoring system subjected to a microwave assisted dissolution procedure (HNO3–HClO4–HF)17VariousAir particlesXRF;—;S PIXE;—;SFast, sensitive, non-destructive analysis carried out as part of research programme into air quality in Northern Italy79VariousAirborne particles—;—;—Review on compositional heterogeneity of airborne particles. Number of differing surface techniques highlighted80VariousAir particlesMS;—;SAerosol TOF system used to provide aerodynamic sizing and compositional data on individual particles. Chemical composition obtained by performing laser desorption ionization of individual particles using a Nd∶YAG laser (266 nm)81VariousAerosolsXRF;—;S NAA;—;S AE;—;SInterlaboratory comparison carried out on aerosol samples collected on Whatman 41 filters28VariousAir particlesXRF;—;S PIXE;—;SInterlaboratory comparison carried out. Good agreement for most elements obtained. Differences noted for S in lightly loaded samples and with data generated using IC. Variability significantly decreased when identical samplers employed29VariousAir particlesXRF;—;S AA;F;SNon-destructive analysis carried out as part of research programme into air quality near Greek lignite power plants. Pb analysed using AAS. Levels significantly lower than current regulatory limits82VariousAir particlesXRF;—;SNon-destructive analysis carried out as part of research programme into air quality in Natal, Brazil83VariousAir particlesXRF;—;S PIXE;—;S INAA;—;SIntercomparison trials between the three techniques carried out. The need for reference filter samples highlighted in order to assess bias between the techniques30VariousAir articlesTXRF;—;SEvaluation of a microwave assisted vapour phase acid digestion procedure carried out84VariousUrban airXRF;—;SImpact of pollution sources assessed using a receptor model85VariousAir;—;—;—Atomic Spectrometry Update—Environmental analysis7VariousAtmospheric particulatesXPS;—;SSurface analysis of particulates collected on Cu foils (passive samplers) carried out. C and O identified as the major species with traces of Na, NO3−, Cl and SO42−detected. Work demonstrated the variability in chemical composition across particle surfaces39VariousSedimenting dustsAA;—;SSamples dried at 105 °C and mineralized by boiling with 10 mHNO3under reflux for 4 h86VariousAtmospheric aerosolsAA;—;SElemental analysis carried out after precipitation in a gas discharge tube atomizer. Both impact and electrostatic precipitation investigated. Electrostatic precipitation exhibited a higher sampling efficiency than the impaction strategy87VariousAtmospheric particlesXRF;—;SReview of microprobe techniques with tube and synchrotron excitation sources presented3VariousAirborne particulate matterMS;ICP;SLA (Nd∶YAG at 1064 nm) performed on samples collected onto PTFE filters. NIST 1648 Urban Particulate Matter used to prepare calibration filters. >20 elements determined24VariousFlue gasAE;—;GReal-time multi-metal continuous-emission monitor prototype developed. Tests conducted in conjunction with US EPA at an incinerator plant showed promise for the measurement of metals such as Be, Cd, Cr and Pb10VariousWood and cooking fumesXRF;—;SData used to help construct specific profiles for use in model for apportionment of fine particle sources in the Denver region of Colorado USA88VariousAirborne dustTXRF;—;SReview of methods for sample preparation, microwave-assisted vapour phase acid dissolution or slurry formation recommended4VariousAirborne particulate matterAE;MIP;S, LHe plasma sustained within graphite furnace containing coaxially placed graphite rod antenna. Sequential thermal desorption used for metal fractionation studies. Size fractionated air samples from Hong Kong analysed89VariousWorkplace airAE;ICP;LFive sample dissolution procedures tested within an inter-laboratory trial. Closed vessel microwave assisted procedures gave the best performance31VariousWorkplace airAE;ICP;G MS;ICP;GVolatile metal and metalloid species trapped on AgNO3impregnated quartz filters. Samples analysed after dissolution in 10% HNO3Alternatively, samples cryogenically trapped at –175 °C onto glass wool packed column followed by analysis by GC-ICP-MS37VariousAirborne particulate matterAE;ICP;S MS;ICP;GFilter samples digested and analysed. Magnetic sector-multicollector instrument used to determine Pb isotopic ratios. Direct filter sampling using LA proved to be a rapid means of obtaining data90VariousAirborne particulate matter—;—;—Sampling techniques to produce realistic filter samples for method evaluation studies discussed32VariousFlue gasesAE;ICP;GFlue gas analysed on-line. Desolvated USN used to produce calibration aerosols. To minimize errors, calibration should ideally be carried out with a gas of similar composition to the flue gas being analysed91VariousArctic hazeMS;ICP;SParticulate matter collected onto graphite discs mounted behind nozzles of a cascade impactor. Discs analysed using an ETA sampling system15VariousAirborne particlesAA;—;— —;ICP;—Review of AA and ICP techniques for the analysis of airborne particles5VariousAir—;—;—Environmental analysis review. Section entitled Air analysis applications92VariousAirAE;ICP;S MS;ICP;SBook chapter review. Filtration sampling, sample dissolution and analysis discussed93VariousAirborne particulate matterAE;ICP;S MS;ICP;SPt group elements leached from filter media. Separation and preconcentration carried out using modified C18silica gel column (as ion associates of their chlorocomplexes). Analytes eluted using ethanol, evaporated and analysed. Recoveries 100 ± 3% at the 1–20 µg level94VariousAir particulatesEMPA;—;SC, O and N measured in individual particles using optimized windowless EMPA95VariousAir—;—;—Industrial hygiene chemistry review961.1Sample collection and pretreatmentContinuing on from last year's review,7publication of papers detailing the development ofcontinuous emission monitoring(CEM) instruments for on-line gas monitoring continue to grow. Research groups investigating CEM systems based uponon-line ICP-AEScontinue to address problems associated with introducing waste air into plasmas. Selzer describes his approach to correct for CN emission bands8whilst Gomeset al.studied the effects of water vapour loading on the plasma temperature and resultant detection limits obtainable.9Alternativelaser based techniquessuch as LIBS and LIPS have been proposed for applications such as trace metals in stack gases,10in ventilation hoods above electroplating baths11and the determination of C, S and halogens in air for potential use in chemical weapons verification programmes.12The development of these systems aided by advances in laser, fibre optic and solid state detector technologies will bring the goal of portable instrumentation for field use a step closer.Advocates ofimpaction and electrostatic precipitator type samplerscontinue to research this sampling option. Luedke13has studied the elemental composition of size fractionated aerosol collected at an Arctic research station. Graphite plates were used as targets behind the nozzles of a cascade impactor sampler. These plates were subsequently placed within an ETV-ICP-MS system for analysis. In a similar vein, and carrying on the work of the Sneddon group, Lee and co-workers14,15studied the sampling characteristics of an graphite impactor system coupled to ETAAS.1.2Instrumental analysis1.2.1Atomic absorption and atomic emission spectrometrySuch is the established nature of these techniques, operating in a conventional fashion, that few or no novel papers have appeared over the last year. The majority of papers reviewed were concerned with the use of these techniques for routine monitoring/survey work.16–191.2.2X‐ray fluorescenceAs highlighted in previous reviews, XRF techniques remain popular for the analysis of airborne particulate matter. The portability of smallenergy dispersive XRFinstruments continues to be exploited for field use. Kienbusch and co‐workers20used an EDXRF instrument for the analysis of Pb on air filter samples taken at paint removal operations. Comparisons with results obtained on filters dissolved and analysed by ICP-AES were encouraging and demonstrated the feasibility of this approach. However, it was disappointing to note the lack of papers detailing the use of online EDXRF systems for air analysis.1.2.3Mass spectrometryLike ICP-AES/AA techniques, the maturity ofICP-MSsystems has been exploited for the routine analysis of airborne particulate matter.17,21An interesting application published was the determination of129I in ambient air.22Condensate samples (from chilled surfaces) were initially stabilized in a 0.25 mNaOH solution. Samples were then precipitated onto a filter membrane as PdI2by the addition of PdCl2. The filter samples were placed within a miniature quartz furnace and heated to liberate I2, which was subsequently flushed into the plasma torch. Correction from129Xe was required but the detection limit calculated from standards was found to be 30 fg. Improvements are required for quantitative sample collection and to reduce the Xe interference. Nomizu and co‐workers in Japan23are developing an ICP-MS system for the elemental analysis of individual airborne particulates. Direct sampling of air into the plasma is used. Currently, they are using a newly developed high-speed pulse counting digital circuit board to measure flash signals from individual particles.Use of alternativesolid sample introductory systemssuch as the above mentioned ETV13,15and laser ablation24,25,859remain hindered by calibration difficulties and the knowledge that XRF techniques can at times do the job more efficiently. The ability of ICP-MS techniques to perform rapid isotopic measurements continues to be exploited for source apportionment studies as highlighted in an investigative study of dustfall in the vicinity of a Pb mining operation.261.3TrendsThree areas of development have been highlighted: namely, the use of round-robin trials to improve analytical quality, speciation of metals and metalloids and the examination of single atmospheric particles.1.3.1Interlaboratory trialsAir analysis, in this author's opinion, remains the poor relation, with respect to other fields of environmental analysis. The lack of suitable reference materials and the slow development of proficiency testing schemes employing realistic samples has lead to a number of workers questioning the quality of data obtained.27–32However, these researchers are making attempts to improve the situation. Cortes and Chilean co-workers exchanged filters between laboratories and compared data obtained using INAA, PIXE, XRF, IC and AAS.27In an attempt to minimize variability between samplers, a second batch of filter samples was taken at one location with identical samplers and was subsequently distributed. Canadian workers compared PIXE with XRF and similarly found better correlation when identical air samplers were employed.29Staff at IAEA noted good agreement between INAA, PIXE and EDXRF when used for the analysis of bulk samples and particulates captured on filters.30They concluded that reference materials would help increase data quality. Following on from this, the work of scientists at the Health and Safety Laboratory demonstrated that it is possible to produce large numbers of near identical filter samples using multi-port sampler technology.31,321.3.2SpeciationThe interest in thespeciation of airborne particulate mattercontinues to grow.Operationally defined speciationexperiments using sequential leaching protocols are now being applied to airborne particulate matter. Andersen and co-workers studied the degree of exposure to soluble (leached with ammonium citrate) and insoluble nickel (HNO3–HClO4–H2SO4digestion) in Ni refinery dust.33Researchers in Italy used a similar approach (4‐step procedure) for the speciation of Cd in samples obtained from a coal fired power station. Careful consideration is required as to the validity of carrying out such experiments and how the data fits in with the understanding of exposure and health effects.As reported last year a number of workers continue to exploit GC-ICP-MS34–36for theanalysis of volatile metal(loid) species,e.g., methylated Pb, Se and Sn species. In an interesting presentation, French workers investigated the work environment in the microelectronic industries where highly toxic metal(loid) species are used in vapour phase deposition operations.37They recognised that it was important to have simple, robust methods if routine regulatory sampling for such species will be required in the future. In conjunction with the use of hyphenated systems they examined the use of chemically impregnated filters (AgNO3) to trap volatile species. Samples are simply analysed by ICP techniques following digestion in dilute nitric acid. Along similar lines, a patent application for a sampling system to collect mixed phase samples was presented.38This sampler utilizes a twin filter system with the first filter, at ambient temperature, to collect the particulate phase and the second filter, at a temperature below ambient, to remove the vapour phase.1.3.3Single particle analysisThe analysis of single particles, looking at both bulk and surface properties, is attracting a great deal of attention. Current status of many of the techniques employed can be found in the review articles noted above. Hutton and Williams demonstrated the potential of imaging XPS to show localized variations across surfaces of individual particulates.39In a similar vein Japanese workers compared XPS and XAS techniques and concluded that XAS was more suitable for the chemical state analysis of S in aerosol samples.40This demanding area of analysis is providing aerosol scientists with a better understanding of particle source and formation and the consequences to human health arising from exposure.

ISSN:0267-9477    

出版商:RSC    

年代:1999

数据来源: RSC