ASTM E1832-2008(2012) Standard Practice for Describing and Specifying a Direct Current Plasma Atomic Emission Spectrometer《说明和规定直流等离子光谱发射计特性的标准操作规程》.pdf
《ASTM E1832-2008(2012) Standard Practice for Describing and Specifying a Direct Current Plasma Atomic Emission Spectrometer《说明和规定直流等离子光谱发射计特性的标准操作规程》.pdf》由会员分享,可在线阅读,更多相关《ASTM E1832-2008(2012) Standard Practice for Describing and Specifying a Direct Current Plasma Atomic Emission Spectrometer《说明和规定直流等离子光谱发射计特性的标准操作规程》.pdf(6页珍藏版)》请在麦多课文档分享上搜索。
1、Designation: E1832 08 (Reapproved 2012)Standard Practice forDescribing and Specifying a Direct Current Plasma AtomicEmission Spectrometer1This standard is issued under the fixed designation E1832; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、 of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice describes the components of a directcurrent plasma (DCP) atomic emission spect
3、rometer. Thispractice does not attempt to specify component tolerances orperformance criteria. This practice does, however, attempt toidentify critical factors affecting bias, precision, and sensitivity.A prospective user should consult with the vendor beforeplacing an order to design a testing prot
4、ocol for demonstratingthat the instrument meets all anticipated needs.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the
5、 applica-bility of regulatory limitations prior to use. Specific hazardsstatements are give in Section 9.2. Referenced Documents2.1 ASTM Standards:2E135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Related MaterialsE158 Practice for Fundamental Calculations to ConvertIntensities
6、 into Concentrations in Optical Emission Spec-trochemical Analysis (Withdrawn 2004)3E172 Practice for Describing and Specifying the ExcitationSource in Emission SpectrochemicalAnalysis (Withdrawn2001)3E406 Practice for Using Controlled Atmospheres in Spec-trochemical AnalysisE416 Practice for Planni
7、ng and Safe Operation of a Spec-trochemical Laboratory (Withdrawn 2005)3E520 Practice for Describing Photomultiplier Detectors inEmission and Absorption SpectrometryE528 Practice for Grounding Basic Optical Emission Spec-trochemical Equipment (Withdrawn 1998)3E1097 Guide for Determination of Various
8、 Elements byDirect Current Plasma Atomic Emission Spectrometry3. Terminology3.1 For terminology relating to emission spectrometry, referto Terminology E135.4. Significance and Use4.1 This practice describes the essential components of theDCP spectrometer. This description allows the user or potentia
9、luser to gain a basic understanding of this system. It alsoprovides a means of comparing and evaluating this system withsimilar systems, as well as understanding the capabilities andlimitations of each instrument.5. Overview5.1 A DCP spectrometer is an instrument for determiningconcentration of elem
10、ents in solution. It typically is comprisedof several assemblies including a direct current (dc) electricalsource, a sample introduction system, components to form andcontain the plasma, an entrance slit, elements to disperseradiation emitted from the plasma, one or more exit slits, oneor more photo
11、multipliers for converting the emitted radiationinto electrical current, one or more electrical capacitors forstoring this current as electrical charge, electrical circuitry formeasuring the voltage on each storage device, and a dedicatedcomputer with printer. The liquid sample is introduced into as
12、pray chamber at a right angle to a stream of argon gas. Thesample is broken up into a fine aerosol by this argon stream andcarried into the plasma produced by a dc-arc discharge betweena tungsten electrode and two or more graphite electrodes.When the sample passes through the plasma, it is vaporized
13、and atomized, and many elements are ionized. Free atoms andions are excited from their ground states. When electrons ofexcited atoms and ions fall to a lower-energy state, photons ofspecific wavelengths unique to each emitting species areemitted. This radiation, focussed by a lens onto the entrance
14、slitof the spectrometer and directed to an echelle grating and1This practice is under the jurisdiction of ASTM Committee E01 on AnalyticalChemistry for Metals, Ores, and Related Materials and is the direct responsibility ofSubcommittee E01.20 on Fundamental Practices.Current edition approved Dec. 1,
15、 2012. Published December 2012. Originallyapproved in 1996. Last previous edition approved in 2003 as E1832 03, which waswithdrawn October 2004 and reinstated in May 2008. DOI: 10.1520/E1832-08R12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service a
16、t serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohoc
17、ken, PA 19428-2959. United States1quartz prism, is dispersed into higher orders of diffraction.Control on the diffraction order is accomplished by thelow-dispersion echelle grating. Radiation of specific wave-length or wavelengths passes through exit slits and impinges ona photomultiplier or photomu
18、ltipliers. The current outputscharge high-quality capacitors, and the voltages thus generatedare measured and directed to the computer. Using calibrationsolutions, a calibration curve is generated for each element ofinterest. The computer compares the signals arising from themany elements in the sam
19、ple to the appropriate calibrationcurve and then calculates the concentration of each element.Over seventy elements may be determined. Detection limits ina simple aqueous solution are less than 1 mg/L for most ofthese elements. Mineral acids or organic liquids also may beused as solvents, and detect
20、ion limits are usually within anorder of magnitude of those obtained with water. Detectionlimits may be improved by using preconcentration procedures.Solid samples are dissolved before analysis.6. Description of Equipment6.1 Echelle SpectrometerComponents of the equipmentshown in Fig. 1 and describe
21、d in this section are typical of acommercially available spectrometer.Although a specific spec-trometer is described herein, other spectrometers having equalor better performance may be satisfactory. The spectrometer isa Czerny-Turner mount and consists of a condensing lens infront of an entrance sl
22、it, a collimating mirror, combineddispersing elements (grating and prism), focus mirror, exit slits,photomultipliers, control panel, and wavelength selectormechanism.6.1.1 Condensing Lens, placed between the DCP source andthe entrance slit. It should have a focal length capable offocusing an image o
23、f the source on the entrance slit and withsufficient diameter to fill the aperture of the spectrometer withradiant energy.6.1.2 Entrance Slit, although available with fixed width andheight, a slit variable in both width and height provides greaterflexibility. Typical values are 0.025 mm to 0.500 mm
24、in widthand 0.100 mm to 0.500 mm in height. Adjustable slit widthsand heights are useful in obtaining optimal spectral band widthand radiant energy entering the spectrometer for the require-ments of the analytical method.6.1.3 Collimating Mirror, renders all rays parallel afterentering the spectrome
- 1.请仔细阅读文档,确保文档完整性,对于不预览、不比对内容而直接下载带来的问题本站不予受理。
- 2.下载的文档,不会出现我们的网址水印。
- 3、该文档所得收入(下载+内容+预览)归上传者、原创作者;如果您是本文档原作者,请点此认领!既往收益都归您。
下载文档到电脑,查找使用更方便
5000 积分 0人已下载
下载 | 加入VIP,交流精品资源 |
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- ASTME183220082012STANDARDPRACTICEFORDESCRIBINGANDSPECIFYINGADIRECTCURRENTPLASMAATOMICEMISSIONSPECTROMETER

链接地址:http://www.mydoc123.com/p-529592.html