Bursting bubble flow microextraction combined with gas chromatography for determination of organochlorine pesticides in aqueous samples

Abstract

Bubble-bursting flow microextraction (BBFME) is a simple and powerful microextraction method that conforms to the principles of green analytical chemistry (GAC). This method, combined with GC, is used for extraction, pre-concentration, and determination of some organochlorine pesticides (OCPs) in aqueous samples. In this method, the target analytes are transferred to the surface of the sample solution by the flow of gas bubbles. After the bubbles burst, the analytes disperse into the upper space and are finally collected and extracted. One of the unique properties of gas bubbles is the creation of a two-phase liquid–gas system, whereby the extraction process occurs at the liquid–gas interface where analytes interact with gas molecules in the bubble. In this study, a new method based on the availability of gas bubbles was proposed and investigated. The conditions affecting BBFME performance, including extraction time, the effect of ionic strength, and sample pH were investigated. Under optimal conditions, the dynamic linear range was 0.74–100.0 μg L-1, and the limit of detection and limit of quantification were 0.24–0.33 and 0.74–0.98 μg L-1, respectively. The range of enrichment factor and recovery under optimal conditions was between 228 and 273 and between 82.1 % and 98.2 %, respectively. Finally, using the BBFME method, the toxins simazine, γ-BHC, alachlor, aldrin and dieldrin were successfully extracted from various aqueous samples with satisfactory relative recoveries ranging from 95.3 to 105.1 %.