ASTM D7875-20

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it may 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 version
of the standard as published by ASTM is to be considered the official document.
Designation: D7875 − 14 D7875 − 20
Standard Test Method for
Determination of Butanol and Acetone Content of Butanol
for Blending with Gasoline by Gas Chromatography
This standard is issued under the fixed designation D7875; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Scope*
1.1 This test method covers the determination of the butanol content of butanol for blending with gasoline by gas chromatography.
1.2 Butanol is determined from 95 % to 99.9 % by mass, acetone is determined from 0.02 % to 1.5 % by mass, ethanol is
determined from 0.02 % to 1.5 % by mass, and methanol is determined from 0.02 % to 1.5 % by mass. Equations used to convert
these individual components from mass percent to volume percent are provided. This test method has not been evaluated for use
with the butanol isomer 2-methyl-2-propanol.
1.3 This test method identifies and quantifies acetone, ethanol, and methanol, but does not purport to identify all individual
components that may be present in butanol for gasoline blending.
1.4 Water cannot be determined by this test method and shall be measured by a procedure such as Test Method D1364 and the
result used to correct the chromatographic values.
1.5 This test method is inappropriate for impurities that boil at temperatures higher than 225 °C or for impurities that cause poor
or no response in a flame ionization detector, such as water.
1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.8 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.04.0L on Gas Chromatography Methods.
Current edition approved July 1, 2014Dec. 1, 2020. Published September 2014January 2021. Originally approved in 2014. Last previous edition approved in 2014 as
D7875 – 14. DOI: 10.1520/D7875-14.10.1520/D7875-20.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7875 − 20
D1298 Test Method for Density, Relative Density, or API Gravity of Crude Petroleum and Liquid Petroleum Products by
Hydrometer Method
D1364 Test Method for Water in Volatile Solvents (Karl Fischer Reagent Titration Method)
D4052 Test Method for Density, Relative Density, and API Gravity of Liquids by Digital Density Meter
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4307 Practice for Preparation of Liquid Blends for Use as Analytical Standards
D4626 Practice for Calculation of Gas Chromatographic Response Factors
D4806 Specification for Denatured Fuel Ethanol for Blending with Gasolines for Use as Automotive Spark-Ignition Engine Fuel
D6299 Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measure-
ment System Performance
D6300 Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products, Liquid Fuels, and
Lubricants
D7862 Specification for Butanol for Blending with Gasoline for Use as Automotive Spark-Ignition Engine Fuel
E355 Practice for Gas Chromatography Terms and Relationships
E594 Practice for Testing Flame Ionization Detectors Used in Gas or Supercritical Fluid Chromatography
E1064 Test Method for Water in Organic Liquids by Coulometric Karl Fischer Titration
3. Terminology
3.1 Definitions—This test method makes reference to many common gas chromatographic procedures, terms, and relationships.
Detailed definitions can be found in Practices E355 and E594.
3.1.1 butanol, n—for the purposes of this method, butanol or butyl alcohol refers to one of three structural isomers of
butanol—1-butanol, 2-butanol, and 2-methyl-1-propanol. This test method has not been evaluated for use with the butanol isomer
2-methyl-2-propanol. to: 1-butanol or n-butanol (CH3CH2CH2CH2OH), 2-butanol or sec-butanol (CH3CH(OH)CH2CH3), and
2-methyl-1-propanol or iso-butanol (CH3CH(CH3)CH2OH), three isomeric alcohols with the molecular formula C4H9OH, either
individually or as mixtures.
4. Summary of Test Method
4.1 A representative aliquot of the butanol sample is introduced into a gas chromatograph equipped with a polydimethylsiloxane
bonded phase capillary column. Helium carrier gas transports the vaporized aliquot through the column where the components are
separated by the chromatographic process. Components are sensed by a flame ionization detector as they elute from the column.
The detector signal is processed by an electronic data acquisition system. The butanol, acetone, ethanol, and methanol components
are identified by comparing their retention times to the ones identified by analyzing standards under identical conditions. The
concentrations of all components are determined in mass percent area by normalization of the peak areas.
5. Significance and Use
5.1 Butanol is being approved for blending with gasoline in accordance with Specification D7862. This test method provides a
method of determining the percentage of butanol (purity) of the butanol for blending with gasoline.
6. Apparatus
6.1 Gas Chromatograph, capable of operating at the conditions listed in Table 1. A heated flash vaporizing injector designed to
provide a linear sample split injection (for example, 200:1) is required for proper sample introduction. Carrier gas controls shall
be of adequate precision to provide reproducible column flows and split ratios in order to maintain analytical integrity. Pressure
control devices and gauges shall be designed to attain the linear velocity required in the column used. A hydrogen flame ionization
detector with associated gas controls and electronics, designed for optimum response with open tubular columns, is required.
6.2 Sample Introduction—Manual or automatic liquid syringe sample injection to the splitting injector is employed. Devices
capable of 1.0 μL injections are suitable. It should be noted that inadequate splitter design, poor injection technique, and
overloading the column can result in poor resolution. Avoid overloading, particularly of the butanol peak(s), and eliminate this
condition during analysis.
6.3 Column—This test method utilizes a fused silica open tubular column with non-polar polydimethylsiloxane bonded
(cross-linked) phase internal coating. Any column with equivalent or better chromatographic efficiency and selectivity to that
described in 6.3.1 can be used.
D7875 − 20
TABLE 1 Typical Operating Conditions
Column Temperature Program
Column length 150 m
Initial temperature 75 °C
Initial hold time 7 min
Program rate 15 °C/min
Final temperature 250 °C
Final hold time 15 min
Injector
Temperature 300 °C
Split ratio 200:1
Sample size 0.1
Detector
Type Flame ionization
Temperature 300 °C
Fuel gas Hydrogen ('30 mL/min)
Oxidizing gas Air ('300 mL/min)
Make-up gas Nitrogen ('30 mL/min)
Carrier Gas
Type Helium
Average linear velocity 18 cms to 20 cm/s
6.3.1 Open tubular column with a non-polar polydimethylsiloxane bonded (cross-linked) phase internal coating; a 150 m long by
0.25 mm internal diameter column with a 1.0 μm film thickness has been found to be suitable.
6.4 Electronic Data Acquisition System—Any data acquisition and integration device used for quantification of these analyses
must meet or exceed these minimum requirements:
6.4.1 Capacity for at least 80 peaks/analysis,
6.4.2 Normalized percent calculation based on peak area and using response factors,
6.4.3 Identification of individual components based on retention time,
6.4.4 Noise and spike rejection capability,
6.4.5 Sampling rate for narrow (<1 s) peaks,
6.4.6 Positive and negative sloping baseline correction,
6.4.7 Peak detection sensitivity compensation for narrow and broad peaks, and
6.4.8 Non-resolved peaks separated by perpendicular drop or tangential skimming as needed.
7. Reagents and Materials
7.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society where such
specifications are available.
7.2 Carrier Gas, helium, with a minimum purity of 99.95 % by mol. Oxygen removal systems and gas purifiers should be used
to attain such purity or method performance. (Warning—Helium, compressed gas under high pressure.)
7.3 Detector Gases, hydrogen, air, and nitrogen. The minimum purity of the gases used should be 99.95 % by mol for the hydrogen
and nitrogen. The air should be hydrocarbon-free grade. Gas purifiers are recommended for the detector gases to attain required
Reagent Chemicals, American Chemical Society Specifications,ACS Reagent Chemicals, Specifications and Procedures for Reagents and Standard-Grade Reference
Materials, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed by the American Chemical Society, see Analar Standards for
Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC),
Rockville, MD.
D7875 − 20
purity or method performance. (Warning—Hydrogen, extremely flammable gas under high pressure.) (Warning—Air and
nitrogen, compressed gases under high pressure.)
7.4 Standards for Calibration and Identification—Standards of all components to be analyzed are required for establishing
identification by retention time as well as calibration for quantitative measurements. These materials shall be of known purity and
free of the other components to be analyzed.
7.4.1 2-Methyl-1-propanol or isobutanol (Warning—Flammable and may be harmful or fatal, if ingested or inhaled.)
7.4.2 1-Butanol or normal butanol (Warning—Flammable and may be harmful or fatal, if ingested or inhaled.)
7.4.3 2-Butanol or secondary butanol (Warning—Flammable and may be harmful or fatal, if ingested or inhaled.)
7.4.4 Acetone (Warning—Flammable and may be harmful or fatal, if ingested or inhaled.)
7.4.5 3-Methyl-1-butanol (Warning—Flammable and may be harmful or fatal, if ingested or inhaled.)
7.4.6 2-Propanol (Warning—Flammable and may be harmful or fatal, if ingested or inhaled.)
7.4.7 2-Butanone (Warning—Flammable and may be harmful or fatal, if ingested or inhaled.)
7.4.8 Ethanol (Warning—Flammable and may be harmful or fatal, if ingested or inhaled.)
7.4.9 Methanol (Warning—Flammable and may be harmful or fatal, if ingested or inhaled.)
NOTE 1—Two grades of ethanol are available. Only absolute ethanol 99.5 minimum percent meets the requirements of this test method.
8. Sampling
8.1 Butanol may be sampled into an open container since a vapor pressure of less than 21 kPa is expected. Refer to Practice D4057
for instruction on manual sampling from bulk storage into open containers. Stopper the container immediately after drawing the
sample.
8.2 Transfer an aliquot of the sample into a septum vial and seal. Obtain the test sample for analysis directly from the sealed
septum vial, for either manual or automatic syringe injection.
9. Preparation of Apparatus
9.1 Install and condition column in accordance with manufacturer’s or supplier’s instructions. After conditioning, attach column
outlet to flame ionization detector inlet and check for leaks throughout the system. When leaks are found, tighten or replace fittings
before proceeding.
9.2 Adjust the carrier gas flow rate so that the average linear gas velocity, at the initial temperature of the run, is between
1818 cm ⁄s and 2020 cm cm/s, ⁄s, as determined by the following equation:
L
μ¯ 5 (1)
t
m
where:
μ¯ = average linear gas velocity (cm/s),
L = column length (cm), and
t = retention time of methane.
m
Flow rate adjustment is made by raising or lowering the carrier gas pressure (head pressure) to the injector.
9.3 Adjust the operating conditions of the gas chromatograph (Table 1) and allow the system to equilibrate.
9.4 Linearity—The linearity of
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