Bubbles in Solvent Microextraction: The Influence of Intentionally Introduced Bubbles on Extraction Efficiency

• Published in: Analytical chemistry (Washington) Vol. 83; no. 17; pp. 6713 - 6716
• Main Authors: Williams, D. Bradley G, George, Mosotho J, Meyer, Riaan, Marjanovic, Ljiljana
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.09.2011
• Subjects: Air; Analytical chemistry; Bubbles; Chemistry; Exact sciences and technology; Fruit - chemistry; Gas Chromatography-Mass Spectrometry - methods; Pesticides; Pesticides - analysis; Pesticides - isolation & purification; Phase transitions; Solution chemistry; Solvent extraction processes; Solvents - chemistry; Triazines - analysis; Triazines - isolation & purification; Water; Use; Pesticides; Matrix effect; Air; Concentration; Method; Solvent extraction; Droplet; Fruit juice; Certified reference material; Herbicide; Thin film; Chemical enrichment; Solid phase microextraction; Improvement; Sample preparation; Efficiency; Detection limit; Technique; Surface area; Solvent
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac201323z

Significant improvements to microdrop extractions of triazine pesticides are realized by the intentional incorporation of an air bubble into the solvent microdroplet used in this microextraction technique. The increase is attributed partly to greater droplet surface area resulting from the air bubble being incorporated into the solvent droplet as opposed to it sitting thereon and partly to thin film phenomena. The method is useful at nanogram/liter levels (LOD 0.002–0.012 μg/L, LOQ 0.007–0.039 μg/L), is precise (7–12% at 10 μg/L concentration level), and is validated against certified reference materials containing 0.5 and 5.0 μg/L analyte. It tolerates water and fruit juice as matrixes without serious matrix effects. This new development brings a simple, inexpensive, and efficient preconcentration technique to bear which rivals solid phase microextraction methods.