Determination of 2-Octanone in Biological Samples Using Liquid–Liquid Microextractions Followed by Gas Chromatography–Flame Ionization Detection

Background: Analysis of chemicals in biological fluids is required in many areas of medical sciences. Rapid, highly efficient, and reliable dispersive and air assisted liquid–liquid microextraction methods followed by gas chromatography-flame ionization detection were developed for the extraction, preconcentration, and determination of 2-octanone in human plasma and urine samples.

Methods: Proteins of plasma samples are precipitated by adding methanol and urine sample is diluted with water prior to performing the microextraction procedure. Fine organic solvent droplets are formed by repeated suction and injection of the mixture of sample solution and extraction solvent into a test tube with a glass syringe. After extraction, phase separation is performed by centrifuging and the enriched analyte in the sedimented organic phase is determined by the separation system. The main factors influencing the extraction efficiency including extraction solvent type and volume, salt addition, pH, and extraction times are investigated.

Results: Under the optimized conditions, the proposed method showed good precision (relative standard deviation less than 7%). Limit of detection and lower limit of quantification for 2-octanone were obtained in the range of 0.1–0.5 µg mL−1. The linear ranges were 0.5-500 and 0.5-200 µg mL−1 in plasma and urine, respectively (r2 ≥ 0.9995). Enrichment factors were in the range of 13-37. Good recoveries (55–86%) were obtained for the spiked samples.

Conclusion: Preconcentration methods coupled with GC analysis were developed and could be used to monitor 2-octanone in biological samples.