Organic-inorganic sol-gel hybrid and magnetic sporopollenin-based composites as solid phase-based extraction of selected aldehydes and drugs analysis

Abstract

The effectiveness of microextraction method is strongly dependent on the selection of suitable sorbent material for the target analyte/s. Production of an efficient and easily handled sorbent material is challenging. The use of sorbent based on a single material often exhibits limited physicochemical properties. Thus, combining the advantages of different materials especially from renewable or less toxic sources is preferred to obtain an eco-friendly composite with enhanced performance. In this study, three organic-inorganic composites were successfully synthesized as new extraction materials for selected organic compounds from different aqueous samples. The first sorbent, methyltrimethoxysilane-(3-mercaptopropyl)trimethoxysilane (MTMOS-MPTMOS) was successfully used as coating material in hollow fiber-solid phase microextraction (HF-SPME) and applied to the extraction of hexanal and heptanal in urine samples. MTMOS-MPTMOS HF-SPME method showed good limits of detection (LOD) (3 S/N) (0.010 µg mL-1 for hexanal and 0.015 µg mL-1 for heptanal), excellent accuracies (recovery = 91.21 - 97.51%) and good precisions (RSD < 5.6%). The ease of sorbent preparation and simplicity in use made the MTMOS-MPTMOS HF-SPME as a potential tool for detecting volatile organic compounds in real samples. The second sorbent, magnetic sporopollenin-3-cyanopropyltriethoxysilane (MS-CNPrTEOS) was synthesized and successfully evaluated as a new sorbent candidate for use in dispersive micro-magnetic solid phase extraction (D-µ-MSPE) for the determination of selected non-steroidal anti-inflammatory drugs (NSAIDs) and tricyclic antidepressants (TCAs) in water samples. Magnetic sporopollenin composite functionalized calix[4]arene derivative (Calix-MS) was prepared as the third new sorbent and successfully employed for D-µ-MSPE of selected NSAIDs in water samples. The developed methods using both MS-CNPrTEOS and Calix-MS provided low LODs (3s) at ppb levels (< 0.50 µg L-1), good linearities (R2 = 0.9951) and accuracies (> 86%). Findings revealed that the bio-based sporopollenin composites exhibited good extraction capability, good stability (reusable) and sufficient magnetic property to greatly simplify the extraction process. Based on the analytical eco-scale, the greenness of MTMOS-MPTMOS HF-SPME method is excellent while D-µ-MSPE using MS-CNPrTEOS and Calix-MS as sorbents are classified as acceptable green analytical methods. The three developed methods showed high potential as green alternative methods for determination of organic compounds in aqueous samples.