ASTM D4307-2017 Standard Practice for Preparation of Liquid Blends for Use as Analytical Standards《制备作为分析标准用液体混合物的标准实施规程》.pdf

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1、Designation: D4307 99 (Reapproved 2015)D4307 17Standard 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 revisi

2、on, 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. Scope Scope*1.1 This practice covers a laboratory procedure for the preparation of small volumes of multicompon

3、ent liquid blends for useas analytical standards.1.2 This practice is applicable to components that are normally liquids at ambient temperature and pressure, or solids that willform a solution when blended with liquids. Butanes can be included if precaution is used in blending them.1.3 This practice

4、 is limited to those components that fulfill the following conditions:1.3.1 They are completely soluble in the final blend.1.3.2 They are not reactive with other blend components or with blend containers.1.3.3 The combined vapor pressure of the blended components is such that there is no selective e

5、vaporation of any of thecomponents.1.3.3.1 The butane content of the blend is not to exceed 10 %. (WarningExtremely flammable liquefied gas under pressure.Vapor reduces oxygen available for breathing.) Components with a vapor pressure higher than butanes are not to be blended.1.4 The values stated i

6、n SI units are to be regarded as the standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regula

7、torylimitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organiza

8、tion Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D1364 Test Method for Water in Volatile Solvents (Karl Fischer Reagent Titration Method)3. Summary of Practice3.1 The individual blend components are precisely weighed and combined in an inert, tight sealing

9、tight-sealing glass vial orsimilar container. When volatility is a consideration, the components of lowest vapor pressure (least volatile) are added first andthe highest (most volatile) last. Mass (weight) percent composition of the final blend is calculated from the mass and purities ofthe pure com

10、ponents. Volume percent composition can be calculated using the density of each component.4. Significance and Use4.1 The laboratory preparation of liquid blends of known composition is required to provide analytical standards for thecalibration of chromatographic and other types of analytical instru

11、mentation.5. Apparatus5.1 Containers:1 This practice is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.04.0A on Preparation of Standard Hydrocarbon Blends.Current edition approved Oct. 1, 2015May 1,

12、 2017. Published December 2015May 2017. Originally approved in 1983. Last previous edition approved in 20102015 asD4307 99 (2010).(2015). DOI: 10.1520/D4307-99R15.10.1520/D4307-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org.

13、 For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit ma

14、y not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at th

15、e end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.1.1 Vial, glass, threaded neck, approximately 22 mL capacity, short style. Vials of other capacitycapacities may besubstituted,substituted as required. When blend

16、ing light sensitive light-sensitive components, use amber glass vials or wrap clearglass vials with black tape.5.1.2 Bottle Cap, molded plastic with TFE-fluorocarbon, polypropylene, or polyethylene conical liner.5.1.3 Bottle Cap, molded plastic with aluminum-foil liner. Aluminum-foil aluminum foil l

17、iner. Aluminum foil liners arepreferred to other metal liners because they seal better.5.1.4 Mininert Valve, screw cap, 20 mm or appropriate size to match vial size used. These caps are especially valuable forpreparing blends that contain volatile components.NOTE 1The use of Mininert valves is recom

18、mended when components 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 Components, high-purity, as required depending on the composition req

19、uirements of the proposed blend.6.1.1 To verify the purity of blend components, analyze each compound by the same technique for which the blend is intendedor by another suitable technique. Check for other impurities such as water, if necessary. Water cannot be determined with sufficientaccuracy by m

20、ost GC methods and must be measured by other procedures such as Test Method D1364, or equivalent, and the resultused to normalize the chromatographic value. If any of the impurities found are other components of the blend, determine theirconcentrations and make appropriate corrections.7. Procedure7.

21、1 Examine the vial and cap to verify that a leak-free closure is obtained. The rim at the top of the vial should be smooth andflat and the cap should fit snugly.7.1.1 Glass vials are inert to most compounds and are the usual choice. Plastic containers shall never be used since specificcompounds can

22、preferentially diffuse through them.7.1.2 Plastic caps with aluminum-foil aluminum foil liners provide a good seal unless blend components react with thealuminum. Polyethylene or polypropylene-lined caps usually provide a good closure but are not to be used for aromatichydrocarbons and similar compo

23、unds since these materials will, with time, diffuse through the liner.7.2 Weigh the vial and cap to the nearest 0.1 mg. Remove the cap and add the first component to the vial, being careful not toallow the component to contact the rim of the vial, which could produce losses. Liquids may be added by

24、either pipet or medicinedropper while solids are usually added with a small spatula. Place the cap on the vial and reweigh to the nearest 0.1 mg0.1 mg,recording the mass. Repeat this procedure with each additional component, always being careful not to allow the contents of thevial to contact the ca

25、p. After all components have been added and the final weighing completed, thoroughly shake the vial to mixthe solution.7.2.1 When volatile components are being combined, the lowest vapor pressure (least volatile) compound is added first and thehighest (most volatile) last.NOTE 2Exercise care when ad

26、ding additional components since the resulting agitation can lead to excessive loss of headspace and acts to amplifythe preferential removal of more volatile components from the blend. This condition is further amplified by the fact that each time the vial cap is removed,the equilibrium of the heads

27、pace will be altered. Since liquid films form spontaneously on the vial caps from super-saturated headspaces and fromequilibrium processes of evaporation and condensation (especially if the vial is cooled), all of the blend components should be added to the blend in asshort a time as is reasonable.7

28、.2.2 For blending very volatile components, it is advisable to reduce the volatility when the vial is uncapped by cooling thevial to about 4 C between weighings. When this technique is utilized, the volatile component is added, and the vial is closed andweighed. The vial and contents then are chille

29、d thoroughly before the vial is opened to allow addition of the next component. Thenext component is added quickly, the vial closed, and the vial and contents brought to ambient temperature before the mass isobtained. Exercise care to ensure that moisture condensed on the exterior of the vial is rem

30、oved before weighing. After weighing,the vial and contents are re-chilled before the vial is opened to permit addition of the next component.7.3 To prepare a blend containing components at low concentration, for example, mg/kg, where the weighed quantities wouldbe too small for sufficient accuracy,

31、it is necessary to make an initial blend of those components at higher concentrations.Successive dilutions are then made until the final desired concentration is reached. For example, if a blend is desired that contains56 mgkg (mass-ppm) n-heptane in cyclohexane, weigh together 2 mL of n-heptane and

32、 20 mL of cyclohexane. Make certain thatbetween all weighings the unmixed liquid does not contact the container cap, which could cause preferential losses. After bothcomponents have been added, thoroughly mix this blend by shaking. Make three successive dilutions, with careful weighings, of1one part

33、 (2 mL) of blend with 10ten parts (20 mL) of cyclohexane. Shake thoroughly between each dilution. Each blend shouldhave a finished volume of 22 mL so that quantities are large enough to weigh accurately. The mass-ppm of n-heptane in the finalblend is calculated from the recorded weights.D4307 1728.

34、Preblending Calculations8.1 In order to make blends of components at specific levels, it is necessary to calculate beforehand the mass of each componentrequired to achieve these levels. Calculate these masses as follows:WN 5 AT100 (1)where:WN = mass of component N to be added, g,A = desired mass per

35、centage in the final blend, andT = desired mass of the total final blend, g.9. Calculations9.1 Calculate the mass percent concentration of each component as follows:N,mass%5 WN 3100(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

36、 (see 6.1.1), corrections shall be made to the mass of that compound,as well as to other components included in the blend. For example, if the mass of component N added to the blend is 3.0 g butprevious analysis indicated it to be 95 % component N, 3 % component O, and 2 % component P, then the actu

37、al mass ofcomponent 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 of components O andP, respectively.9.1.1.1 When a standard being prepared contains one or more components being used as an internal standard, Eq 2 shall notinclude the mass of the internal

38、standard component(s) in the denominator summation when calculating the mass percent of theother components in the blend. The mass of the internal standard component(s) is only included in the denominator summationin Eq 2 when calculating the mass percent of the internal standard component(s) in the

39、 blend.9.1.1.2 Example CalculationsThe following mixture was prepared (for simplicity, purities were not taken into account for thisexample).Component Mass (g)Methyl tert-Butyl Ether 15.02Ethanol 10.05Methanol 5.021-Propanol 3.03Gasoline 66.881,2-Dimethoxyethane 5.25Calculations:Sample: 15.02 g + 10

40、.05 g + 5.02 g + 3.03 g + 66.88 g = 100.00 gMTBE Concentration: 15.02 g/100.00 g = 15.02 % by massEthanol Concentration: 10.05 g/100.00 g = 10.05 % by massMethanol Concentration: 5.02 g/100.00 g = 5.02 % by mass1-Propanol Concentration: 3.03 g/100.00 g = 3.03 % by massInternal standard calculation:1

41、,2-Dimethoxyethane Concentration: 5.25 g/105.25 g = 4.99 % by mass9.2 Calculate the volume percent concentration of each component as follows:N,volume%5 WN/DN! 3100(WN/DN!1WO/DO!1WP/DP! .#(3)where:WN, WO, WP = mass of components N,O,P, etc, g, andDN, DO, DP = density of components N,O,P, etc., all d

42、etermined at the same temperature.9.2.1 The final volume of the solution is not necessarily the same as the sum of the volumes of the components due to possibleexpansion or contraction on mixing.9.2.1.1 When a standard being prepared contains one or more components being used as an internal standard

43、, Eq 3 shall notinclude the mass/density ratio of the internal standard component(s) in the denominator summation when calculating the volumepercent of the other components in the blend. The mass/density ratio of the internal standard component(s) is only included in thedenominator summation of Eq 3

44、 when calculating the volume percent of the internal standard component(s) in the blend.10. Keywords10.1 analytical standards; liquid blendsD4307 173SUMMARY OF CHANGESSubcommittee D02.04 has identified the location of selected changes to this standard since the last issue(D4307 99 (2015) that may im

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