Salting-out-assisted liquid–liquid extraction for the preconcentration and quantitative determination of eight herbicide residues simultaneously in different water samples with high-performance liquid chromatography

ABSTRACT

Salting˗out-assisted liquid–liquid extraction coupled with high-performance liquid chromatography was developed for selective extraction and preconcentration of five s-triazine herbicides and three major metabolites of atrazine simultaneously. Under the optimum conditions, detection and quantification limits (ng mL⁻¹) were found in the range 0.02–0.19 and 0.06–0.65, respectively. Linearity ranges (ng mL⁻¹) of 1–60 (ametrin), 2–160 (desethylatrazine, desisopropyl atrazine, secbumetone and terbutryn) and 4–240 (hydroxyatrazine and aziprotryn) were obtained. The relative standard deviations for the intra- and inter-day precisions were in the ranges 0.3–8.5% and 5.4–9.8%, respectively. Relative recoveries of three spiked water samples were in the ranges of 72.5–114.6, 74.6–109.2 and 62.5–109.6% for the river, lake and underground water samples, respectively.

KEYWORDS:

• Atrazine
• phase separation
• salting-out-assisted liquid–liquid extraction
• s-triazine
• trace enrichment

Acknowledgement

Material support from the International Science Program (ISP) through the pesticide project (ETH: 04) is greatly acknowledged.

Funding

The authors are very much grateful for the support from the Chemistry Department of Addis Ababa University and the Chemistry Department of Haramaya University.