Solid-Phase Microextraction Research Laboratory
Team SPiRAL
Our laboratory focuses on the development and optimization of Solid Phase Microextraction (SPME) techniques for applications in analytical chemistry and environmental science. We apply SPME to detect pesticide residues in dry fruits, fruits, and vegetables with high sensitivity and accuracy. Our research also includes biomedical applications, such as identifying antibiotic growth promoters and respiratory pathogens. A major goal is to improve SPME performance in complex sample types. We aim to develop reliable and practical methods that support food safety, environmental monitoring, and clinical diagnostics. Through this work, we contribute to the advancement of analytical tools for public health and safety.
Quantification of Environmentally Hazardous 4-Chlorophenol in Water
Chlorinated compounds in water pose significant environmental and health concerns, necessitating the development of efficient and rapid monitoring strategies to ensure environmental protection and regulatory compliance. Unlike conventional analytical approaches that often involve complex sample preparation and instrumentation, our group has developed a novel paper-based thin film solid-phase microextraction (TF-SPME) patch for the detection of 4-chlorophenol (4-CRP), a well-established and hazardous environmental pollutant. This innovative platform integrates a composite of divinylbenzene, polydimethylsiloxane, and multi-walled carbon nanotubes onto a paper substrate using a thin film applicator, enabling uniform coating and enhanced extraction capability. In our testing, TF-SPME patches were directly exposed to aqueous solutions containing varying concentrations of 4-CRP and subsequently analyzed using gas chromatography–mass spectrometry (GC-MS). Our data revealed strong extraction performance with a detection limit of approximately 10 ng/mL, highlighting the practical utility of this technique for monitoring chlorinated contaminants within acceptable regulatory limits. To evaluate the quantitative capacity of the method, we generated a calibration curve across a concentration range of 100–10,000 ng/mL, resulting in a precise curve-fitting equation for estimating unknown 4-CRP levels. These findings underscore the potential of our paper-based TF-SPME system as a simple, scalable, and cost-effective solution for the real-time surveillance of hazardous pollutants in water. Ongoing research in our laboratory aims to expand the applicability of this platform to other chlorinated compounds and further optimize its integration into environmental monitoring workflows.
Fabrication of disposable microextraction analytical tool for in vitro detection of Staphylococcus bacterial pathogen using volatile metabolites emission
A disposable paper-based thin film solid-phase microextraction (TF-SPME) patch was developed for the detection of Staphylococcus aureus bacterial pathogen. The study was based on the extraction of volatile organic compounds from the bacterial culture medium by a nanoparticle blended polymer-coated microextraction patch and then analyzed by gas chromatography-mass spectrometry to identify the volatile metabolic signature associated with the bacterial pathogen during the growth phase of the bacterial species in the culture medium. The TF-SPME patches were fabricated using a divinylbenzene/multiwall carbon nanotube/polydimethylsiloxane coating mixture employing a film applicator for uniform coating on a regular cellular paper substrate. The coated sheet was dried and trimmed into multiple small-dimension sampling patches before exposure to the Staphylococcus bacterial solution. To check the eco-friendliness of the proposed technique in terms of green analytical chemistry, the ‘Blue Applicability Grade Index’ (BAGI) was determined to be around 62.5, suggesting the feasibility of considering the proposed analytical method as a green sample preparation approach for clinical application. Therefore, this technique utilizing the TF-SPME patches may be utilized as an alternative and rapid method for the identification of Staphylococcus bacterial pathogens as an alternative to the traditional prolonged culture-based study. Furthermore, the microextraction patch is disposable and easy to fabricate, suggesting the feasibility of utilizing it as a pathological sampling kit for the characterization of Staphylococcus bacterial pathogen.
Design of a cost-effective fiberglass-coated thin-film microextraction device for the detection of bendiocarb, carbofuran and atrazine agrochemicals from water
Agrochemicals are widely used during the farming process to protect crops from pests and improve agricultural productivity. These pesticides accumulate in regular water sources, posing potential hazards to the environment and human health. To simplify the detection of three common agrochemicals (bendiocarb, carbofuran insecticides, and atrazine herbicide), fiberglass-based thin-film solid-phase microextraction (TFSPME) devices were developed. To optimize the sample preparation technique, various parameters, including extraction time, temperature, desorption time, solvent profile,
ionic strength, and stirring rate, were investigated with the 2000ng/mL standard mixture of three agrochemicals. The results showed that TF-SPME patches were able to extract pesticides with a LOD of 0.1 ng/mL. To further simply the technique, a concentration dependent calibration curve (100-900 ng/mL) was constructed for individual pesticides and the fitting equations were derived, facilitating the fast quantification of these agrochemicals. The developed technique aligned with the green analytical principles due to low solvent use, minimal waste generation, and energy efficiency. The AGREE score emphasized its strong connection with green chemistry, while complex GAPI and BAGI validated its environmental compatibility and user safety. This microextraction TF-SPME device may be applicable for the rapid quantification of agrochemicals from water resources to safeguard human lives.
Development of a disposable paper-based thin film solid-phase microextraction sampling kit to quantify ketone body
Diabetes ketoacidosis (DKA) is a life-threatening complication and requires immediate medical attention in the case of diabetes subjects, especially in the case of type 1 diabetes mellitus. In the condition of DKA, the body produces an excess amount of ketone bodies after unregulated fat degradation, causing blood to become acidic and hampering the regular metabolic activities of the body. The current diagnostic technique for DKA condition is based on monitoring ketone bodies, especially β-hydroxybutyric acid, from human urine and blood samples. The detection of serum ketone bodies in pathology is sometimes limited due to false positive results and the lack of standardization for precise quantification of analytes. In this study, a paper-based patch operating on the thin film solid-phase microextraction (TF-SPME) principle was developed and it was coupled with gas chromatography-mass spectrometry for simple quantification of b-hydroxybutyric acid (BHB) ketone body from a phosphate-buffered saline matrix. To fabricate the paper-based TF-SPME patches, a regular A4 sheet paper sheet was utilized as the substrate and uniform coating by multiwalled carbon nanotubes (MWCNT), polydimethylsiloxane (PDMS) and divinyl benzene (DVB) compounds was performed with an automatic film applicator. The 70 mm paper-based coated sheet was trimmed into 4 cm × 1 cm dimension pieces to obtain multiple patches from a single sheet. Extraction of the BHB ketone body into the closed vials was performed by exploiting the individual DVB/PDMS and DVB/CNT/PDMS paper patches followed by desorption with acetonitrile before quantification by gas chromatography-mass spectrometry analysis. Our study showed that the BHB extraction efficiency of DVB/PDMS-coated patches was higher than that of DVB/CNT/PDMS. The outcome showed a good linearity (R2 = 0.99) within the 500–20 000 ng mL−1 concentration range of BHB by paper-based DVB/PDMS patches. This study demonstrated the feasibility of utilizing simple, cost-effective paper-based disposable TF-SPME patches as a sampling kit for future screening of diabetes ketoacidosis without the need for prolonged traditional sample preparation in pathology.