ASTM D4307-1999(2004) Standard Practice for Preparation of Liquid Blends for Use as Analytical Standards《作为分析标准的液体掺混物制备的标准操作规程》.pdf

1、Designation: D 4307 99 (Reapproved 2004)An American National StandardStandard Practice forPreparation of Liquid Blends for Use as AnalyticalStandards1This standard is issued under the fixed designation D 4307; the number immediately following the designation indicates the year oforiginal adoption or

2、, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers a laboratory procedure for thepreparation of small volume

3、s of multicomponent liquid blendsfor 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

4、 This practice is limited to those 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 n

5、o selective evaporation of any of thecomponents.1.3.3.1 The butane content of the blend is not to exceed10 %. (Warning: Extremely 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 v

6、alues stated in SI units are to be 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-bi

7、lity of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1364 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

8、vial or similarcontainer. When volatility 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 percen

9、t composition can be calcu-lated using 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

10、.1 Containers:5.1.1 Vial, glass, threaded neck, approximately 22-mL ca-pacity, 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-fluor

11、ocarbon,polypropylene, or polyethylene 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 especial

12、ly valuable forpreparing blends that 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 sty

13、le.6. Reagents and Materials6.1 Blend 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 and Lubricants and is the direct responsibility of Subcommittee D02.04 onHydro

14、carbon Analysis.Current edition approved May 1, 2004. Published May 2004. Originallyapproved in 1983. Last previous edition approved in 1999 as D 4307 99.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMS

15、tandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.1.1 To verify the purity of blend components, analyzeeach compound by the same technique f

16、or 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 D 1364,or equivalent, and the result used to norm

17、alize 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 the top of the vial should besmooth and

18、 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 provide a goodseal unless blend components re

19、act 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 the nearest 0.1 mg. Removethe cap and add

20、 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 vial and reweigh to the nearest 0.1mg

21、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 solution.7.2.1 When volatile components are

22、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 the preferential removal of more volatil

23、e 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 equilibrium processes of evaporation and

24、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 coolingthe vial to about 4C between weighing

25、s. 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 vialclosed and the vial and contents brou

26、ght 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 thenext component.7.3 To prepare a blend

27、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 until thefinal desired concentration is rea

28、ched. 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 couldcause preferential losses. After both

29、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. Shakethoroughly between each dilution. Each blend should have afinished volume of 22 mL so that quantities are large

30、 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 eachcomponent required to achieve these levels.

31、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-ponent as follows:N, mass % 5WN3 100(WN1 Wo

32、1 WP!(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 component N added to theblend is 3.0 g

33、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 Calculate the volume percent concentration

34、 of eachcomponent as follows:N, volume % 5WN/DN! 3 100(WN/DN! 1 WO/DO! 1 WP/DP! .(3)where:WN,WO,WP= mass of components N, O, P, etc, g, andD 4307 99 (2004)2DN,DO,DP= density of components N, O, P, etc., alldetermined at the same temperature.9.2.1 The final volume of the solution is not necessarily t

35、hesame 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 item mentionedin this standard. U

36、sers 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 committee and must be reviewed eve

37、ry 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 meeting of theresponsible techn

38、ical 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 Drive, 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).D 4307 99 (2004)3