The florpirauxifen-benzyl is a herbicide classified as toxicological III, which belongs to the arylpicolinate group in the synthetic auxin class. This compound was recently released in Brazil for the usage in rice, corn and soy cultures. Considering this recent release, it´s important that the extraction and quantification methods of this compound are well consolidated, contributing to the mitigation of possible damage. This work aimed to optimize the solid-liquid extraction with low temperature purification (ESL-PBT) for the determination of florpirauxifen-benzyl in soil samples through a high efficiency liquid chromatography with a diode arrangements detector (HPLC-DAD). The extraction method is based on using 4.0 g of soil and 4.0 mL of water. Then 8 mL of the extraction phase is added. The obtained system is homogenized in vortex for 1 min and kept at -20 ºC until the complete freezing of the soil and water mixture. After this step, 5 mL of the organic phase containing the florpirauxifen-benzyl were completely evaporated under an air flow and immediately resuspended in 400 µL of acetonitrile. The ESL-PBT optimization was performed through a complete 23 factorial design, the studied variables were: extraction phase (8 mL of acetonitrile and 1.5 mL of ethyl acetate + 6.5 mL of acetonitrile); freezing time (60 and 120 min) and ionic strength (0 and 0.2 g of NaCl). The used chromatographic conditions were: 243 nm wavelength, mobile phase composed of 100% acetonitrile, 30 ºC column temperature, 20.0 µL injection volume, 0.4 mL min-1 mobile phase flow, EC-C18 120 Poroshell column (4.6 x 50 mm, 2.7 µm, Agilent Technologies). The compound signal occurred at the 1.5 minutes retention time. The obtained results demonstrated that the increase in the freezing time reduced the standard deviation. The NaCl addition increased the ionic strength of the system, however, it made it more difficult the formation of a single phase, reducing the extraction percentage of the compound. The polarity reduction of the extraction phase by the addition of ethyl acetate to the acetonitrile provided an extraction percentage superior to 100% and a <10% standard deviation, with a lower baseline elevation, showing a better chromatographic response. This behavior can be explained by the high solubility of the compound in the ethyl acetate solvente (120 g L-1). For this work, the optimal extraction conditions were 8 mL of acetonitrile, without the addition of salt and freezing time of 120 min. This metodology will be submitted to the validation step using the main merit figures: linearity range, detection and quantification limits, selectivity, accuracy and precision.