Development and greenness evaluation of solid-phase extraction and salting-out liquid-liquid extraction method for determination of herbicides in water, soil and rice

Solid-phase extraction (SPE) and salting-out-assisted liquid-liquid extraction (SALLE) method was optimized and validated for the extraction and quantification of anilofos, bispyribac sodium, butachlor, pendimethalin, pretilachlor and penoxsulam from environmental water, soil and rice samples using HPLC and LC-MS/MS. The limit of detection and limit of quantification ranged from 0.0026 to 0.03 and 0.008 to 0.09 mu g mL(-1) in different matrices using HPLC and LC-MS/MS. Under the optimal conditions, mean percent recoveries ranged from 81.6 +/- 4.1 to 98.6 +/- 3.5, 84.1 +/- 3.5 to 99.4 +/- 3.2 and 81.3 +/- 4.2 to 94.6 +/- 3.5 in water, soil and rice, respectively, using SPE while 84.9 +/- 2.9 to 102.3 +/- 2.3, 90.0 +/- 4.1 to 103.2 +/- 4.1 and 86.3 +/- 2.7 to 94.6 +/- 3.5 using SALLE. Acceptable recoveries (> 80%) and precision (< 10%) for studied herbicides in water, soil and rice samples were obtained using SPE and SALLE. Further, the greenness was evaluated using AGREE metrics and Analytical Eco-Scale. SPE and SALLE were found to be greener methods and were efficient for the determination of herbicides from water, soil and rice. However, SALLE is advantageous over SPE in terms of cost-effectiveness, simplicity and easy handling. SALLE was used for extraction and quantification of herbicide from environmental water, soil and rice samples. Herbicide concentrations in soil and water samples at 0 day varied from 0.083 +/- 1.65 to 1.381 +/- 1.41 mu g g(-1). The concentration of studied herbicides in soil, rice and water at harvest was below the permissible limit (< 0.01 mu g g(-1)).