In industries like oil and gas, petrochemicals, and environmental compliance, understanding where hydrocarbons are coming from—and in what quantity—isn’t optional. It's essential. This is where hydrocarbon source testing comes in.
In this post, we’ll break down the full process of hydrocarbon source testing—from the moment a sample is taken, to the final lab analysis that informs crucial decisions. Whether you're managing compliance, reducing emissions, or troubleshooting leaks, understanding the technical journey matters.
Looking for a clear, step-by-step guide to hydrocarbon source testing? You’re in the right place.
Snapshot Summary: What You’ll Learn
Hydrocarbon source testing is the process of identifying and quantifying volatile and semi-volatile organic compounds (VOCs and SVOCs) released from equipment, emissions points, or contaminated soil and water.
Here’s what you’ll take away from this guide:
What types of hydrocarbons are typically tested (and why)
Sampling methods for different environments
Analytical techniques used in modern labs
How to ensure accurate, defensible data
Common pitfalls and how to avoid them
Want to dive deeper into how it’s actually done? Keep reading!
Understanding the Scope: What Are We Testing For?
Hydrocarbons come in many forms, including:
Methane and ethane (light alkanes)
Benzene, toluene, ethylbenzene, xylene (commonly called BTEX)
Polycyclic aromatic hydrocarbons (PAHs) like naphthalene
Volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs)
Each category requires specific handling and analysis techniques, depending on the source (e.g. air stack, wastewater, soil gas) and end goal (e.g. compliance, forensic tracing, process optimisation).
Sampling Techniques: Where Accuracy Begins
1. Air Sampling
For emissions stacks, ambient air, or workplace environments:
Canister Sampling: Stainless steel canisters draw in air and hold it under vacuum until analysis.
Sorbent Tubes: Passive or active collection on materials like Tenax or activated charcoal.
Bag Sampling: Short-term collection using Tedlar bags—cheap but less stable for longer periods.
2. Soil and Groundwater Sampling
Soil Vapour Probes: Access subsurface vapours without excavation.
Purge-and-Trap Systems: Used for water samples to isolate volatile hydrocarbons.
Solid Phase Microextraction (SPME): A solvent-free option that absorbs hydrocarbons directly onto a coated fibre.
3. Process & Equipment Testing
Leak Detection and Repair (LDAR): Uses infrared cameras or flame ionisation detectors (FID) to trace fugitive emissions.
Direct Interface Sampling: Inline or batch-based collection of gas or liquid samples directly from production equipment.
Pro Tip: Always use pre-cleaned, certified containers and follow chain-of-custody procedures to protect data integrity.
Analysis Techniques: From Raw Sample to Usable Data
Once samples are collected, they're sent to a laboratory for precise chemical analysis using techniques such as:
Gas Chromatography–Mass Spectrometry (GC-MS)
The gold standard for separating and identifying individual hydrocarbons. Ideal for BTEX and VOCs.
Flame Ionisation Detection (FID)
Common in field screening and stack testing. Less specific than GC-MS but useful for total hydrocarbon quantification.
Fourier Transform Infrared Spectroscopy (FTIR)
Used for real-time air monitoring and certain process applications. It identifies functional groups in complex compounds.
Gravimetric or Colorimetric Methods
Simple but effective in field conditions—especially for oil and grease in water.
Did You Know? Results from hydrocarbon source testing are often used in legal proceedings or compliance reports—accuracy and defensibility are non-negotiable.
Quick Guide: When Source Testing Gets Complicated
The Situation:
An industrial facility noticed higher-than-usual hydrocarbon readings near a storage area. While regulatory thresholds weren’t exceeded yet, the team needed to pinpoint the source fast—without shutting down operations.
Common Challenges:
Which source is actually leaking?
Are elevated readings due to weather, equipment, or contamination?
How do you prove findings to regulators or stakeholders?
How to Solve It:
1. Use Portable Screening Tools First: Deploy handheld FID or PID detectors to narrow down suspect areas before deeper testing.
2. Apply a Tiered Sampling Strategy: Start broad with ambient air sampling. Move to targeted soil gas or process line testing based on initial results.
3. Engage an Accredited Lab Early: Don’t wait until after sampling to involve the lab. Pre-approval of containers, detection limits, and holding times avoids costly retests.
4. Document Everything Clearly: Maintain clear chain-of-custody, calibration logs, and technician notes. These often matter more than the data itself when justifying decisions.
Why It Works:
This step-by-step method allows teams to move quickly, focus efforts efficiently, and produce data regulators can trust—without wasting time or money chasing false leads.
Need help planning or reviewing your source testing process? Reach out for a second set of eyes—we’ve helped dozens of teams tighten their approach.
Frequently Asked Questions (FAQs)
Q1: How often should hydrocarbon source testing be done?
A: Frequency depends on your industry and local regulations. For example, annual or quarterly testing is common for EPA-regulated air stacks, while one-time soil gas sampling may be used during a property transaction or remediation.
Q2: What’s the difference between VOC and SVOC testing?
VOCs: Light compounds like benzene or toluene.
SVOCs: Heavier, less volatile compounds like PAHs.
Different sampling and analysis methods are used—VOCs are captured via air canisters or sorbent tubes, while SVOCs may require solvent extraction or SPME.
Q3: Is it possible to do hydrocarbon source testing in-house?
A: Field screening tools like PIDs or FIDs can be used in-house. However, full laboratory analysis requires accredited labs with calibrated equipment, controlled environments, and skilled chemists.
Q4: What can go wrong during sampling?
Common mistakes include:
Using incorrect containers
Contaminating samples
Missing holding times
Incomplete documentation
These issues can lead to inaccurate results, regulatory pushback, or wasted costs.
Conclusion
Hydrocarbon source testing is more than just a regulatory checkbox—it’s the foundation of responsible operations, environmental protection, and risk mitigation.
From choosing the right sampling method to interpreting GC-MS results, every step must be executed with precision and purpose. Cutting corners can lead to expensive mistakes, while a well-planned testing process can reveal insights that prevent leaks, fines, and reputational damage.
Whether you’re new to the topic or looking to upgrade your current approach, understanding the full testing journey—from sampling to analysis—is key to smarter decisions and safer operations.
