Application of the concept of design space in method development for the determination of contaminants in soil

Abstract

The analysis of polycyclic aromatic hydrocarbons and polychlorinated biphenyls is an important topic in environmental analysis, and several analysis procedures have already been proposed. Following the approach of analytical quality by design (AQbD) contributes to the development of simultaneous identification and quantification of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), alkylated PAHs and aliphatic compounds in soil by the gas chromatography-mass spectrometry (GC-MS) analytical technique, using the mechanical extraction method for sample preparation, which results in the modified method with superior analytical parameters. In the study, the set-up of design space (DS) for method development was introduced, including the selection of an appropriate gas chromatography (GC) column. Subsequently, design of experiment enabled finding the optimal GC conditions for the new method that allowed achieving adequate resolution and recovery. Method development involved changes in sample preparation, making it simpler and faster. Decreasing the number of different extraction steps enabled reducing staff numbers and consumable costs. As a result, methods of analysis of PAHs, PCBs and aliphatic and aromatic compounds in a single run were developed, offering reliable accuracy, precision, linearity and recovery rates that fully comply with Swedish regulations. This new method and its introduction to laboratory practice was validated, and the greenness of the method was evaluated.

Keywords

• environmental chemistry
• method validation
• gas chromatography
• experimental design
• analytical quality by design
• design space