# Exploring the Potential of Microextraction in the Survey of Food Fruits and Vegetable Safety
## 1 Introduction
### Food Safety--Major Contaminants of Fresh Fruits and Vegetables and Their Toxicity  
#### 1.1.1 Pesticides  
Pesticides are applied to protect plants from harmful organisms and pests, including insects (insecticides), weeds (herbicides), rodents, or fungi (fungicides), and to help control diseases [4]. However, their use can lead to long-term hazards for the environment and biodiversity due to their inherent toxicity [13; 14]. Therefore, in recent years, great efforts have been made to develop pesticides that degrade faster, do not accumulate, and have less toxicity to humans and wildlife [4]. Pesticides can be very diverse and constitute a broad family of compounds, such as organochlorines, carbamates, and synthetic pyrethroids. Organochlorines, also known as chlorinated hydrocarbons, are organic pesticides that contain at least five chlorine atoms. Examples of these include dichloro-diphenyl-trichloroethane (DDTm), aldrin, hexachlorocyclohexane (HCH), heptachlor, chlordane, and endosulfan [15] (Figure 1). Organochlorines are effective insecticides due to their ability to harm a wide range of insects. They are structurally related to steroid hormones and act on the respective hormone receptors. For example, DDT and chlordane can cause convulsions and paralysis by disrupting the nervous system of the target pest, ultimately leading to death [13; 16]. These pesticides are volatile and resistant to environmental degradation [17], belonging to the class of persistent organic pollutants with high persistence in the environment [13; 16]. Therefore, these pesticides can accumulate in the food chain and tissues, resulting in chronic exposure to animals and humans [16]. Organophosphorus pesticides contain thiophosphoryl functional groups and are commonly found in the soil, atmosphere, groundwater, and agricultural products. They have moderate effectiveness and low persistence [18]. This group of pesticides is biodegradable and rapidly degrades by hydrolysis when exposed to light, air, and soil, minimizing environmental pollution [17; 19]. However, they pose significant concerns for the environment, health, and food safety, and are detected in small amounts in food and drinking water [17]. Humans can absorb organophosphates through inhalation, ingestion, and dermal penetration [20]. This group of pesticides tends to phosphorylate the acetylcholinesterasekinase enzyme (AChE) [20], thus, acting as AChE inhibitors with implications in the transport of nerve impulses [13]. Chlorpyrifos, diazinon, and dichlorvos are examples of organophosphates, along with parathion and malathion (Figure 1), which are commonly associated with stomach and contact poison, including fumigant infection that results in nerve poisons [13; 15]. Carbamates and organophosphates share similar structures and working principles. Both pesticide groups disrupt nerve impulse transmission at the synaptic level through AChE inhibition, effectively killing target pests. Carbamates (Figure 1) are derived from carbamic acid and naturally degrade within weeks or months, minimizing environmental pollution [17]. They are commonly used as herbicides and fungicides, with examples including carbaryl, aldicarb, carbofuran, ethienocarb, fenobucarb, methomyl, and aminocarb [13; 15]. However, these pesticides may adversely affect renal, hepatic, neurological, reproductive, immune, and metabolic functions in both humans and animals. Additionally, carbamate pesticides are classified as endocrine-disrupting chemicals, as they can interfere with the synthesis, secretion, transport, metabolism, and elimination of a wide range of hormones [21]. Synthetic pyrethroids are a combination of organic pesticides that are manufactured by duplicating natural pyrethrins. They act on the voltage-gated sodium channels in cell membranes, disrupting the sodium ion flux, which leads to the paralysis of the organism [17]. This group of pesticides is mostly used against insects and includes deltamethin, esfenvalerate, fenvalerate, cypermethrin, or permethrin [13; 16].