Vortex-assisted dispersive micro-solid-phase extraction using silica-supported FeO-modified khat (atha edulis) biochar nanocomposite followed by GC-MS for the determination of organochlorine pesticides in juice samples.

In this paper, dispersive micro-solid phase extraction technique was developed for the purpose of extracting and preconcentrating organochlorine pesticide residues in juice samples before their separation and quantitative analysis by gas chromatography-mass spectrometry. A sorbent composed of a silica-supported FeO-modified khat leftover biochar nanocomposite (SiO-FeO-KLBNC) was implemented in the process. To improve the dispersion of the sorbent in the solution, vortex mixer was employed.

Ternary solvent based homogeneous liquid-liquid microextraction for the preconcentration of organochlorine pesticides from water and apple juice samples.

In the present study, the optimal experimental conditions were determined by optimizing the effect of extraction solvent types and volume, salt types and concentration, centrifugation speed and time using one variable at a time. Under optimal experimental conditions, calibration curves were constructed separately using water and apple juice samples as representative matrices, and good linearities were achieved over a wide concentration range of 0.2-1600 ng L with a coefficient of determination () ≥ 0.

Effervescent powder-assisted floating organic solvent-based dispersive liquid-liquid microextraction for determination of organochlorine pesticides in water by GC-MS.

An effervescent powder-assisted floating organic solvent-based dispersive liquid-liquid microextraction was introduced for determination of 13 organochlorine pesticides in water samples. In this method, a less toxic low-density organic solvent was used as extraction solvent. The extraction solvent was dispersed in to the aqueous sample via CO bubbles, generated up on addition of water to a falcon tube containing the mixture of effervescent powder precursors as well as the extraction solvent.