## 1 Introduction  
Water is a renewable resource constantly threatened by numerous sources of pollution. Water quality is influenced by various factors, such as precipitation, climate patterns, soil composition, vegetation cover, geological characteristics, flow dynamics, groundwater sources, and anthropogenic activities. In addition, agriculture also has a considerable impact on water quality, due mainly to fertilizers, pesticides, sediments, and inorganic pollutants [1]. Water pollution arises primarily from agricultural and urban runoff that leaches pesticides into the soil, or from the direct discharge of contaminated wastewater [2, 3]. The main source of this pollution is agricultural leaching, which results in the transfer of these substances from the soil into groundwater or surface water due to rain and irrigation [4]. Over the past decades, the improvement in agricultural yields due to the increasing use of pesticides has raised concerns about their potential risks to human health and the environment [5, 6]. Several studies have investigated the effects of pesticide contact on human health, as well as their potential risks in terms of water pollution, bioaccumulation, air emissions, and soil organisms [7]. The analysis of pesticide residues in water usually involves several stages, mainly including the following: the collection and preparation of samples, extraction, clean-up, separation, and qualitative and quantitative determination. The emergence of green analytical chemistry has led to the development of new extraction methods that have lower human and environmental impacts [8; 9; 10]. Besides liquid-liquid extraction, which is the conventional procedure used for the isolation of trace pesticides from aqueous samples [11], several other techniques have also been used, including solid-phase extraction, dispersive solid-phase extraction [12], matrix solid-phase extraction [13; 14], supported liquid extraction [15], and dispersive liquid-liquid microextraction [16]. Additionally, QuEChERS (quick, easy, cheap, effective, rugged, and safe) is a widely used analytical approach that simplifies the analysis of multiple pesticide residues in fruit, vegetables, cereals, and processed food [17]. The concept of solid-phase microextraction (SPME) was first introduced by [PERSON] et al. in 1990 [18]. This green technique offers several advantages, such as simplicity, low cost, drastic solvent reduction, and improved accuracy, so it was successfully used in various analytical applications. The original design of the device involved a syringe equipped with a fiber coated with a suitable sorbent phase, and several improvements have been made to this technique [19; 20; 21; 22; 23; 24]. In addition, SPME provides two different extraction methods: the direct immersion mode (DI-SPME), where the fiber is fully submersed in the aqueous phase, and the headspace mode (HS-SPME), by placing the fiber in the space above the sample [24]. The most common commercially available polymeric coatings are polydimethylsiloxane (PDMS), polyethylene glycol (PEG), and polyacrylate (PA), while various other materials were developed and used for specific applications [25; 26; 27]. Due to its remarkable properties, PDMS proved to be a versatile and efficient coating for the microextraction of a wide range of trace analytes by SPME [28; 29]. In addition to its availability and low cost, PDMS is thermally and chemically stable; additionally, it can be blended with various polymers and materials to prepare specific sorbents [30; 31]. In 2016, [PERSON] et al. developed a method for the detection of 25 semi-volatile pesticides in groundwater based on SPME coupled with GC/MS. Four different types of fibers were evaluated in the study, including PDMS (100 \(\upmu\)m), PA (85 \(\upmu\)m), CAR/PDMS (75 \(\upmu\)m), and PDMS/DVB (65 \(\upmu\)m), which exhibited the highest extraction efficiency for the investigated pesticides [32].