Microscopic view of cooking oil with PAH molecules being scanned by a beam of light.

Is Your Cooking Oil Safe? New Study Reveals Hidden Dangers of Polycyclic Aromatic Hydrocarbons (PAHs)

Lena Voss in Health & Wellness August 2025 • 4 min read.

"Discover how a fast and sensitive extraction method can help detect harmful PAHs in your edible oils, ensuring safer cooking practices."

Edible oils are a staple in every kitchen, used daily for everything from sautéing vegetables to baking delicious treats. However, a recent study has shed light on a potential hidden danger: the presence of polycyclic aromatic hydrocarbons (PAHs). These compounds, formed during incomplete combustion or pyrolysis of organic matter, can find their way into our food supply, posing risks to our health.

PAHs are a large family of nonpolar and lipophilic organic contaminants. Some PAHs are classified by the International Agency for Research on Cancer (IARC) in group 2A and 2B because of their mutagenicity and carcinogenicity. Because of their fat-loving nature, PAHs tend to accumulate in fat-rich materials such as edible oils. This contamination can occur through environmental pollution, technological processes like smoke-drying, or even the use of non-food-grade mineral oils.

Given the potential health risks, monitoring PAH levels in edible oils is crucial. Traditional methods for detecting these compounds can be time-consuming and require large volumes of solvents. However, a new study introduces a fast, sensitive, and efficient method for isolating and determining PAHs in edible oils, potentially revolutionizing how we approach food safety.

The Innovative MAE-DLLME Technique

Microscopic view of cooking oil with PAH molecules being scanned by a beam of light.

The study, led by Abdorreza Mohammadi and colleagues, details the development and application of a microwave-assisted extraction and dispersive liquid-liquid microextraction (MAE-DLLME) technique, followed by gas chromatography-mass spectrometry (GC-MS). This method allows for the rapid isolation and determination of PAHs in edible oils. The researchers optimized key parameters, including the type and volume of extraction and disperser solvents, microwave time, salt concentration, and pH, using response surface methodology (RSM) based on a central composite design (CCD).

Here’s a closer look at how the MAE-DLLME technique works:

Microwave-Assisted Extraction (MAE): PAHs are extracted from the oil sample using a mixture of acetonitrile/acetone and methanolic KOH in two steps. This process helps to efficiently separate the PAHs from the complex oil matrix.
Dispersive Liquid-Liquid Microextraction (DLLME): A mixture of ethanol (disperser solvent), tetrachloroethylene (extraction solvent), and biphenyl (internal standard) is rapidly injected into the sample solution. This creates a cloudy solution, facilitating the extraction of PAHs.
GC-MS Analysis: After phase separation via centrifugation, the sedimented phase is analyzed using gas chromatography-mass spectrometry (GC-MS). This allows for the precise identification and quantification of the PAHs present in the sample.

The method demonstrated excellent linearity, with calibration curves obtained in the range of 2–500 ng/mL and correlation coefficients (R2) ranging from 0.9346 to 0.9978. Enrichment factors were between 81 and 124 for PAHs, and repeatability, measured as relative standard deviations (RSDs), ranged from 5.2% to 9.1% for all PAH compounds at a concentration of 10 ng/mL. The limits of detection (LODs) and limits of quantitation (LOQs) were also impressively low, ranging from 0.2–2.7 ng/mL and 0.6–9.1 ng/mL, respectively.

Ensuring Safer Cooking Oils

The findings of this study highlight the importance of employing sensitive and efficient methods for detecting PAHs in edible oils. The MAE-DLLME technique coupled with GC-MS offers a powerful tool for ensuring the safety and quality of our cooking oils. By understanding the potential risks and utilizing advanced analytical methods, we can take proactive steps to protect our health and promote safer cooking practices.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1080/10406638.2018.1481110, Alternate LINK

Title: Determination Of Polycyclic Aromatic Hydrocarbons In Edible Oil Using Fast And Sensitive Microwave-Assisted Extraction And Dispersive Liquid–Liquid Microextraction Followed By Gas Chromatography-Mass Spectrometry

Subject: Materials Chemistry

Journal: Polycyclic Aromatic Compounds

Publisher: Informa UK Limited

Authors: Abdorreza Mohammadi, Simin Malek-Mohammadi Jahani, Marzieh Kamankesh, Sahar Jazaeri, Mohammadjavad Eivani, Saeideh Esmaeili, Sajad Abdi

Published: 2018-10-29

Everything You Need To Know

What exactly are Polycyclic Aromatic Hydrocarbons (PAHs), and why are they a concern in edible oils?

Polycyclic Aromatic Hydrocarbons, or PAHs, are a large group of organic contaminants known to be nonpolar and lipophilic, meaning they accumulate in fatty substances like edible oils. Certain PAHs are classified by the International Agency for Research on Cancer (IARC) as potentially mutagenic and carcinogenic, posing health risks when ingested. They can enter edible oils through environmental contamination or industrial processes.

Can you explain how the innovative MAE-DLLME technique works for detecting PAHs in cooking oils?

The MAE-DLLME technique combines Microwave-Assisted Extraction (MAE) and Dispersive Liquid-Liquid Microextraction (DLLME) with Gas Chromatography-Mass Spectrometry (GC-MS). MAE uses acetonitrile/acetone and methanolic KOH to extract PAHs. DLLME then uses ethanol, tetrachloroethylene, and biphenyl to further isolate PAHs. Finally, GC-MS identifies and quantifies the PAHs.

What are the advantages of using the MAE-DLLME method compared to traditional techniques for detecting PAHs?

The MAE-DLLME method offers significant improvements over traditional methods. It is faster, more sensitive, and requires smaller volumes of solvents. The method achieves excellent linearity with calibration curves ranging from 2–500 ng/mL and high correlation coefficients. It also demonstrates high enrichment factors and low limits of detection and quantitation, making it a powerful tool for ensuring food safety.

How was the MAE-DLLME technique optimized for efficient PAH detection, and what role did Response Surface Methodology (RSM) play?

Response Surface Methodology (RSM) based on a central composite design (CCD) was used to optimize parameters within the MAE-DLLME technique. These parameters include the type and volume of extraction and disperser solvents, microwave time, salt concentration, and pH. Optimizing these parameters ensures the method's efficiency and sensitivity in detecting PAHs.

Why is it so important to detect and monitor Polycyclic Aromatic Hydrocarbons (PAHs) in our cooking oils?

The detection of PAHs in edible oils is crucial because these compounds can pose significant health risks. By using sensitive methods like MAE-DLLME coupled with GC-MS, we can identify and quantify PAHs to ensure that edible oils meet safety standards. This helps protect consumers from potential exposure to carcinogenic and mutagenic substances, promoting safer cooking practices and better public health.