A cost effective, sensitive, and environmentally friendly sample preparation method for determination of polycyclic...

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Sample Preparation Techniques

Background:

• Polycyclic Aromatic Hydrocarbons (PAHs) are persistent organic pollutants requiring sensitive detection methods.
• Conventional extraction methods like Soxhlet and Microwave Assisted Extraction (MAE) can be time-consuming and costly.
• There is a need for efficient, cost-effective, and sensitive sample preparation techniques for PAH analysis in solid matrices.

Purpose of the Study:

• To investigate a simple, cost-effective, and sensitive sample preparation technique for determining PAHs in solid samples.
• To evaluate the performance of ultrasonic extraction combined with Stir Bar Sorptive Extraction (SBSE) and thermal desorption-gas chromatography-mass spectrometry.
• To optimize ultrasonic extraction parameters including solvent composition, extraction time, and sample load.

Main Methods:

• Sample preparation involved ultrasonic extraction followed by Stir Bar Sorptive Extraction (SBSE).
• Analysis was performed using thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS).
• Ultrasonic extraction parameters (solvent, time, sample load) were optimized using urban dust (SRM 1649a) and 12 US EPA priority PAHs.

Main Results:

• A combination of non-polar and polar solvents (acetone/hexane mixtures 2:3 and 1:1 v/v) significantly improved PAH extraction efficiency, with recoveries ranging from 63.3% to 122%.
• Shorter sonication times (20 min) were generally more effective than longer times (60 min).
• The optimized ultrasonic extraction (20 min, acetone/hexane 2:3 v/v) demonstrated comparable efficiency to MAE, and the SBSE method achieved low limits of detection (1.7–32 ng L⁻¹) and quantitation (5.8–110 ng L⁻¹).

Conclusions:

• The developed ultrasonic extraction and SBSE method is a simple, cost-effective, and sensitive technique for PAH determination in solid samples.
• This method eliminates the need for a separate clean-up step, increasing laboratory analytical capacity.
• The technique offers significant cost performance advantages over conventional extraction methods like Soxhlet and MAE.