ASTM D7398 Boiling Range Distribution Testing of FAME Biodiesel by GC
ASTM D7398 covers the test technique for the determination of the boiling range distribution of Fatty Acid Methyl Esters (FAME) by gas chromatography; the boiling range has to be between 100 to 615 °C. This standard test method is applicable for blends of diesel and biodiesel (B1–B100). However, it is not applicable for the petroleum with low molecular weight such as, naphtha, reformates, crude oils, and gasoline.
TRUSTED BY
Precision-driven testing for dimensional accuracy and compliance
- Overview
- Scope, Applications, and Benefits
- Test Process
- Specifications
- Instrumentation
- Results and Deliverables
Overview
ASTM D7398 describes a standard test method for determining the boiling range distribution of fatty acid methyl esters (FAME), commonly known as biodiesel, by gas chromatographic simulated distillation. The boiling range characterizes the carbon number distribution of FAME and provides insight into fuel quality, feedstock origin, and compliance with biodiesel specifications.
This method supports biodiesel producers, blenders, and testing laboratories in verifying fuel quality and understanding composition for use as a transportation fuel or fuel blend component.
Scope, Applications, and Benefits
Scope
ASTM D7398 applies to FAME samples and fuel blends with boiling temperatures from 100°C to 615°C (atmospheric equivalent) and determines:
- Cumulative boiling range distribution of FAME components
- Initial boiling point (IBP) and final boiling point (FBP)
- Distribution of C8–C22 fatty acid methyl esters
- Compliance with EN 14214 or ASTM D6751 biodiesel specifications
Applications
- Biodiesel (B100) production quality control
- FAME feedstock composition verification (soy, palm, canola, tallow)
- Biodiesel blend stock characterization (B5, B20)
- Regulatory compliance testing for biofuel programs
- Research on alternative feedstock FAME properties
Benefits
- Provides complete boiling range data requiring less sample than physical distillation
- Enables feedstock origin inference from carbon number distribution
- Rapid analysis supporting high-throughput production testing
- Applicable to both pure FAME and diesel blend components
- Sensitive to heavy-end residues that may indicate contamination or incomplete transesterification
Test Process
Sample Preparation
The FAME sample is dissolved in carbon disulfide at a defined concentration for GC injection.
1GC Analysis
The solution is injected into a GC with a non-polar column and temperature program to separate FAMEs by boiling point.
2Calibration
A certified FAME or n-paraffin calibration mixture is analyzed to establish the boiling point vs. retention time calibration curve.
3SimDis Curve Generation
The elution profile is converted to cumulative weight percent vs. boiling temperature using the calibration data.
4Technical Specifications
| Parameter | Details |
|---|---|
| Standard | ASTM D7398 |
| Test Principle | Simulated distillation by gas chromatography |
| Applicable Materials | Fatty acid methyl esters (biodiesel, FAME blends) |
| Boiling Range Covered | 100°C to 615°C (atmospheric equivalent) |
| Detector | Flame ionization detector (FID) |
| Measured Output | Cumulative wt% vs. boiling temperature |
Instrumentation Used for Testing
- Gas chromatograph with programmable temperature oven (up to ~380°C)
- Non-polar capillary GC column for FAME separation
- FID with hydrogen and air supply
- FAME or n-paraffin calibration standards
- SimDis data processing software for curve generation
Results and Deliverables
- Simulated distillation (SimDis) curve for the FAME sample
- Initial boiling point (IBP) and final boiling point (FBP)
- Cumulative yield at defined boiling temperature cut points
- Heavy-end (high-boiling residue) content indication
- Test report for biodiesel specification compliance or feedstock characterization
Why Choose Infinita Lab for ASTM D7398?
At the core of this breadth is our network of 2,000+ accredited labs in the USA, offering access to over 10,000 test types. From advanced metrology (SEM, TEM, RBS, XPS) to mechanical, dielectric, environmental, and standardized ASTM/ISO testing, we give clients unmatched flexibility, specialization, and scale. You’re not limited by geography, facility, or methodology—Infinita connects you to the right testing, every time.
Looking for a trusted partner to achieve your research goals? Schedule a meeting with us, send us a request, or call us at (888) 878-3090 to learn more about our services and how we can support you. Request a Quote
Frequently Asked Questions
Soy FAME is predominantly C16–C18 fatty acid methyl esters with boiling points roughly between 330°C and 360°C; the narrow boiling range reflects the relatively uniform fatty acid composition of soybean oil.
Different vegetable and animal fat feedstocks have characteristic fatty acid carbon number distributions (e.g., palm oil has higher C16:0, canola has more C18:1, tallow has more saturated C16–C18); the SimDis curve profile reflects these compositional differences.
Yes — the presence of petroleum hydrocarbons in a FAME sample alters the overall boiling curve shape and may introduce fractions outside the expected FAME boiling range, providing an indication of blending or contamination.
A high FBP can indicate the presence of unconverted triglycerides, partial glycerides, or other heavy residues from incomplete transesterification — these can affect engine performance and fuel system deposits.
ASTM D7398 is referenced as a supplementary method for boiling range characterization in the context of FAME analysis; core D6751 specification compliance relies on other primary tests such as D93 (flash point), D445 (viscosity), and D4530 (carbon residue).
Request a Quote
Submit your material details and receive testing procedures, pricing, and turnaround time within 24 hours.
Quick Turnaround and Hasslefree process
Confidentiality Guarantee
Free, No-obligation Consultation
100% Customer Satisfaction
