Analytical approach, dissipation pattern and risk assessment of pesticide residue in green leafy vegetables: A comprehensive review

Abstract

The category of 'leafy vegetables' comprises a wide range of plants, including cabbage, lettuce, leeks, spinach, Swiss chard and kale, and it forms a significant component of the human diet. Typically, leafy vegetables are low in calories and fat, are great sources of vitamins, protein, dietary fibre and minerals (including iron, calcium, and nitrates), and are rich in phytochemicals. To counter the impact of pests on vegetables, a broad variety of pesticides are used. Because of their large surface areas, leafy vegetables are expected to have high residual pesticide levels. As such, a sound analytical approach is needed to detect and quantify residue levels that are equal to or lower than the maximum residue limits, thus rendering the products safe for consumption. Overall, leafy vegetables consumed raw (after a tap water wash only), boiled or steamed contribute 2% of total vegetable consumption globally, and they might have a comparatively greater influence on health than cereal ingestion. Consequently, in this review paper, we highlight the importance of leafy vegetables, the pesticides that are commonly used on them and various analytical techniques, including sample preparation, extraction, clean-up and final detection. The effects on dissipation patterns, pre-harvest residue limits and safety/risks imposed by various pesticides are also reviewed and discussed. In conclusion, environmentally friendly extraction methods coupled with high-throughput techniques with greater reproducibility and lower uncertainty are needed for quantifying residues in leafy vegetables at very low concentrations. Commercial and household food preparation, such as washing, peeling, blanching and cooking are effective in removing most of the pesticide residues that are loosely attached on vegetables.

Pesticide Residues and Risk Assessment from Monitoring Programs in the Largest Production Area of Leafy Vegetables in South Korea: A 15-Year Study

“…These are used to wrap grilled or boiled meat [13]. Pesticides are highly likely to remain in leafy vegetables because leafy vegetables have broad surface areas [14].…”

“…Globally, leafy vegetables (raw, boiled, or steamed) consumed account for 2% of total vegetables. Further, these are thought to have a relatively greater health impact than cereal ingestion [14]. Therefore, the management of residual pesticides in the case of leafy vegetables is more important than other types of vegetables.…”

Multi-residue analysis of 203 pesticides in strawberries by liquid chromatography tandem mass spectrometry in combination with the QuEChERS method

“…Various instrumental techniques, including gas chromatography (GC) with flame ionization or electron capture detection, liquid chromatography (LC) with UV, evaporative light scattering, or fluorescence detection, and GC-MS or MS/MS, have been used to sensitively detect multi-residues (Farha et al, 2018;Guo et al, 2018;Lee et al, 2016). Above all, LC coupled with tandem mass spectrometry (LC-MS/MS) and electrospray ionization (ESI) operating in multiple reaction monitoring (MRM) mode has proven to be the most powerful analytical technique for the quantification of pesticides and has been widely used for their multi-residue analysis owing to its high sensitivity and selectivity (Lee et al, 2016).…”

The multifaceted plant-beneficial rhizobacteria toward agricultural sustainability

“…The application of beneficial rhizobacteria as bioinoculants in controlling pests and pathogenic microorganisms that affect plants has been confirmed to be the best alternative to the use of agrochemicals because it is cheap, environmentally friendly and acts as a sustainable agricultural management approach in protecting plants. This makes plant growth-promoting rhizobacteria an acceptable biological tool for controlling plant diseases and ensuring good agricultural practices (Farha et al 2018). There are a lot of biocontrol agents that are present in the market, but it is crucial to understand their interaction with plants, pathogens, and the environment before their use because the purpose of the application may not be achieved if the plant is already under attack from diseases (Liang et al 2015).…”