ASTM D4307-1999(2015) Standard Practice for Preparation of Liquid Blends for Use as Analytical Standards《制备用作分析标准的液体混合物的标准实施规程》.pdf

1、Designation: D4307 99 (Reapproved 2015)Standard Practice forPreparation of Liquid Blends for Use as AnalyticalStandards1This standard is issued under the fixed designation D4307; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the

2、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 covers a laboratory procedure for thepreparation of small volumes of multicomponent liquid blend

3、sfor use as analytical standards.1.2 This practice is applicable to components that arenormally liquids at ambient temperature and pressure, or solidsthat will form a solution when blended with liquids. Butanescan be included if precaution is used in blending them.1.3 This practice is limited to tho

4、se components that fulfillthe following conditions:1.3.1 They are completely soluble in the final blend.1.3.2 They are not reactive with other blend components orwith blend containers.1.3.3 The combined vapor pressure of the blended compo-nents is such that there is no selective evaporation of any o

5、f thecomponents.1.3.3.1 The butane content of the blend is not to exceed10 %. (WarningExtremely flammable liquefied gas underpressure. Vapor reduces oxygen available for breathing.) Com-ponents with a vapor pressure higher than butanes are not to beblended.1.4 The values stated in SI units are to be

6、 regarded as thestandard.1.5 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 applica-bility of regulatory limitations pri

7、or to use.2. Referenced Documents2.1 ASTM Standards:2D1364 Test Method for Water in Volatile Solvents (KarlFischer Reagent Titration Method)3. Summary of Practice3.1 The individual blend components are precisely weighedand combined in an inert, tight sealing glass vial or similarcontainer. When vola

8、tility is a consideration, the componentsof lowest vapor pressure (least volatile) are added first and thehighest (most volatile) last. Mass (weight) percent compositionof the final blend is calculated from the mass and purities of thepure components. Volume percent composition can be calcu-lated us

9、ing the density of each component.4. Significance and Use4.1 The laboratory preparation of liquid blends of knowncomposition is required to provide analytical standards for thecalibration of chromatographic and other types of analyticalinstrumentation.5. Apparatus5.1 Containers:5.1.1 Vial, glass, th

10、readed neck, approximately 22 mLcapacity, short style. Vials of other capacity may be substituted,as required. When blending light sensitive components, useamber glass vials or wrap clear glass vials with black tape.5.1.2 Bottle Cap, molded plastic with TFE-fluorocarbon,polypropylene, or polyethylen

11、e conical liner.5.1.3 Bottle Cap, molded plastic with aluminum-foil liner.Aluminum-foil liners are preferred to other metal liners be-cause they seal better.5.1.4 Mininert Valve, screw cap, 20 mm or appropriate sizeto match vial size used. These caps are especially valuable forpreparing blends that

12、contain volatile components.NOTE 1The use of Mininert valves is recommended when compo-nents lighter than hexane are contained in the liquid blends.5.2 Balance, capable of weighing to 0.1 mg.5.3 Pipet, dropping, medicine dropper.5.4 Spatula, semi-micro, scoop style.6. Reagents and Materials6.1 Blend

13、 Components, high-purity, as required dependingon the composition requirements of the proposed blend.1This practice is under the jurisdiction of ASTM Committee D02 on PetroleumProducts, Liquid Fuels, and Lubricantsand is the direct responsibility of Subcom-mittee D02.04.0A on Preparation of Standard

14、 Hydrocarbon Blends.Current edition approved Oct. 1, 2015. Published December 2015. Originallyapproved in 1983. Last previous edition approved in 2010 as D4307 99 (2010).DOI: 10.1520/D4307-99R15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at

15、serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States16.1.1 To verify the purity of blend components, anal

16、yzeeach compound by the same technique for which the blend isintended or by another suitable technique. Check for otherimpurities such as water, if necessary. Water cannot be deter-mined with sufficient accuracy by most GC methods and mustbe measured by other procedures such as Test Method D1364,or

17、equivalent, and the result used to normalize the chromato-graphic value. If any of the impurities found are othercomponents of the blend, determine their concentrations andmake appropriate corrections.7. Procedure7.1 Examine the vial and cap to verify that a leak-freeclosure is obtained. The rim at

18、the top of the vial should besmooth and flat and the cap should fit snugly.7.1.1 Glass vials are inert to most compounds and are theusual choice. Plastic containers shall never be used sincespecific compounds can preferentially diffuse through them.7.1.2 Plastic caps with aluminum-foil liners provid

19、e a goodseal unless blend components react with the aluminum. Poly-ethylene or polypropylene-lined caps usually provide a goodclosure but are not to be used for aromatic hydrocarbons andsimilar compounds since these materials will, with time,diffuse through the liner.7.2 Weigh the vial and cap to th

20、e nearest 0.1 mg. Removethe cap and add the first component to the vial, being carefulnot to allow the component to contact the rim of the vial, whichcould produce losses. Liquids may be added by either pipet ormedicine dropper while solids are usually added with a smallspatula. Place the cap on the

21、 vial and reweigh to the nearest0.1 mg recording the mass. Repeat this procedure with eachadditional component always being careful not to allow thecontents of the vial to contact the cap. After all componentshave been added and the final weighing completed, thoroughlyshake the vial to mix the solut

22、ion.7.2.1 When volatile components are being combined, thelowest vapor pressure (least volatile) compound is added firstand the highest (most volatile) last.NOTE 2Exercise care when adding additional components since theresulting agitation can lead to excessive loss of headspace and acts toamplify t

23、he preferential removal of more volatile components from theblend. This condition is further amplified by the fact that each time the vialcap is removed, the equilibrium of the headspace will be altered. Sinceliquid films form spontaneously on the vial caps from super-saturatedheadspaces and from eq

24、uilibrium processes of evaporation and conden-sation (especially if the vial is cooled), all of the blend components shouldbe added to the blend in as short a time as is reasonable.7.2.2 For blending very volatile components, it is advisableto reduce the volatility when the vial is uncapped by cooli

25、ngthe vial to about 4 C between weighings. When this techniqueis utilized, the volatile component is added, and the vial isclosed and weighed. The vial and contents then are chilledthoroughly before the vial is opened to allow addition of thenext component. The next component is added quickly, the v

26、ialclosed and the vial and contents brought to ambient tempera-ture before the mass is obtained. Exercise care to ensure thatmoisture condensed on the exterior of the vial is removedbefore weighing. After weighing, the vial and contents arere-chilled before the vial is opened to permit addition of t

27、henext component.7.3 To prepare a blend containing components at lowconcentration, for example, mg/kg, where the weighed quan-tities would be too small for sufficient accuracy, it is necessaryto make an initial blend of those components at higherconcentrations. Successive dilutions are then made unt

28、il thefinal desired concentration is reached. For example, if a blendis desired that contains 56 mg kg (mass-ppm) n-heptane incyclohexane, weigh together 2 mL of n-heptane and 20 mL ofcyclohexane. Make certain that between all weighings theunmixed liquid does not contact the container cap, which cou

29、ldcause preferential losses. After both components have beenadded, thoroughly mix this blend by shaking. Make threesuccessive dilutions, with careful weighings, of 1 part (2 mL)of blend with 10 parts (20 mL) of cyclohexane. Shake thor-oughly between each dilution. Each blend should have afinished vo

30、lume of 22 mL so that quantities are large enough toweigh accurately. The mass-ppm of n-heptane in the final blendis calculated from the recorded weights.8. Preblending Calculations8.1 In order to make blends of components at specific levels,it is necessary to calculate beforehand the mass of eachco

31、mponent required to achieve these levels. Calculate thesemasses as follows:WN5AT100(1)where:WN= mass of component N to be added, g,A = desired mass percentage in the final blend, andT = desired mass of the total final blend, g.9. Calculations9.1 Calculate the mass percent concentration of each com-p

32、onent as follows:N, mass% 5WN3100(WN1Wo1WP!(2)where:WN,WO,WP= mass of components N, O, P, etc, g.9.1.1 When an added component is less than 100 % pure(see 6.1.1), corrections shall be made to the mass of thatcompound, as well as to other components included in theblend. For example, if the mass of c

33、omponent N added to theblend is 3.0 g but previous analysis indicated it to be 95 %component N, 3 % component O, and 2 % component P, thenthe actual mass of component N in the blend would be 2.85 g,and 0.09 g and 0.06 g would need to be added to the masses ofcomponents O and P, respectively.9.2 Calc

34、ulate the volume percent concentration of eachcomponent as follows:N, volume% 5WN/DN! 3100(WN/DN!1WO/DO!1WP/DP! .#(3)D4307 99 (2015)2where:WN,WO,WP= mass of components N, O, P, etc, g, andDN,DO,DP= density of components N, O, P, etc., alldetermined at the same temperature.9.2.1 The final volume of t

35、he solution is not necessarily thesame as the sum of the volumes of the components due topossible expansion or contraction on mixing.10. Keywords10.1 analytical standards; liquid blendsASTM International takes no position respecting the validity of any patent rights asserted in connection with any i

36、tem mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical co

37、mmittee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a

38、 meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Dri

39、ve, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 99 (2015)3