Hollow Fiber Based Liquid Phase Microextraction Method for the Determination of Three Triazine Herbicides from Locally Brewed Ethiopian Beverages

In this study, hollow-fiber based liquid-phase microextraction method was developed of for selective extraction and/or preconcentration of triazine herbicides (atratone, desmetryn and atrazine) from locally brewed Ethiopian beverages prior to their separation and quantitative determination by high performance liquid chromatography with diode array detector. Parameters influencing extraction efficiency of the method including types of the extraction solvent, volume and pH of the sample solution, shaking speed, extraction time and salt concentration were investigated and optimum conditions were established. Under the optimal conditions limits of detections and quantifications were ranged from 0.02 – 0.04 and 0.05 – 0.12 µg/L, respectively. Calibration curves were linear over the range of 0.1 – 2 µg/L with coefficient of determinations of 0.990 or better. Intra- and inter-day precision studies, which were expressed as relative standard deviations were below 8 %. Satisfactory relative recoveries were also obtained for the target analytes, except for atrazine in Nech Tela and Filter Tela, which exhibited relatively lower recoveries. The results of the study indicated that the proposed method is an efficient alternative for selective extraction and/or preconcentration of residues of the target pesticides form Ethiopian locally brewed beverages as well as other similar sample matrices.