Optimized three‐phase hollow fiber liquid‐phase automated microextraction and its application in ultra‐trace analysis of three pyrethroids in water and fruit samples using high‐performance liquid chromatography‐diode array detection

In the present manuscript, an automated three‐phase hollow fiber liquid‐phase microextraction followed by high‐performance liquid chromatography‐diode array detection is applied for the extraction and determination of three pyrethroids, deltamethrin, fenpropathrin, and permethrin in water and fruit samples. N‐dodecane was selected as a supported liquid membrane (SLM) and its polarity was adjusted by trioctylphosphine oxide one‐variable‐at‐a‐time method was used in order to achieve optimal hollow fiber liquid‐phase microextraction parameters such as type of organic acceptor phase, the composition of SLM, ionic strength of sample solution, extraction time, length of hollow fibers and stirring speed. Under the optimal conditions, the calibration curves for the three pyrethroids were plotted, and figures of merit of the proposed method were calculated. The linear dynamic ranges were in the range of 0.9–200, 0.75–200, and 1.5–200 μg/L for deltamethrin, fenpropathrin, and permethrin, with the coefficient of determination better than 0.998. The limits of detection were in the range of 0.3, 0.25, and 0.5 and the limits of quantification were in the range of 0.9, 0.75, and 1.5 μg/L for deltamethrin, fenpropathrin, and permethrin, respectively. The precision of the method was evaluated in terms of relative standard deviation at two different concentration levels 10 and 50 μg/L. The results of real sample analysis in cucumber exhibited high sensitivity, excellent sample clean‐up, favorable repeatability, and suitable accuracy.