Air-assisted liquid-liquid microextraction by solidifying the floating organic droplets for the rapid determination of seven fungicide residues in juice samples.
A novel air assisted liquid-liquid microextraction using the solidification of a floating organic droplet method (AALLME-SFO) was developed for the rapid and simple determination of seven fungicide residues in juice samples, using the gas chromatography with electron capture detector (GC-ECD). This method combines the advantages of AALLME and dispersive liquid-liquid microextraction based on the solidification of floating organic droplets (DLLME-SFO) for the first time. In this method, a low-density solvent with a melting point near room temperature was used as the extraction solvent, and the emulsion was rapidly formed by pulling in and pushing out the mixture of aqueous sample solution and extraction solvent for ten times repeatedly using a 10-mL glass syringe. After centrifugation, the extractant droplet could be easily collected from the top of the aqueous samples by solidifying it at a temperature lower than the melting point. Under the optimized conditions, good linearities with the correlation coefficients (γ) higher than 0.9959 were obtained and the limits of detection (LOD) varied between 0.02 and 0.25 μgL(-1). The proposed method was applied to determine the target fungicides in juice samples and acceptable recoveries ranged from 72.6% to 114.0% with the relative standard deviations (RSDs) of 2.3-13.0% were achieved. Compared with the conventional DLLME method, the newly proposed method will neither require a highly toxic chlorinated solvent for extraction nor an organic dispersive solvent in the application process; hence, it is more environmentally friendly.
Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, People's Republic of China; College of Science, China Agricultural University, Beijing 100193, People's Republic of China.
Xiangwei
X
You
College of Science, China Agricultural University, Beijing 100193, People's Republic of China.
Zhuokan
Z
Xing
College of Science, China Agricultural University, Beijing 100193, People's Republic of China. Electronic address: liufengmao@cau.edu.cn.
Fengmao
F
Liu
College of Science, China Agricultural University, Beijing 100193, People's Republic of China.
Xu
X
Zhang
Air-assisted liquid–liquid microextraction; Floating organic droplet; Fungicide residues; Juice