Levels of residues and dietary risk assessment of the fungicides myclobutanil, penconazole, tebuconazole, and triadimenol in squash

Abstract

Triazole fungicides may potentially harm human health. The 'quick, easy, cheap, effective, rugged, and safe' approach has become popular for extraction and cleanup during pesticide residue analysis. We aimed to (a) validate a method for the simultaneous determination of myclobutanil, penconazole, tebuconazole, and triadimenol in squash using LC-MS/MS and (b) determine the pre-harvest intervals (PHIs) and assess the related risk of consuming squash cultivated under open-field conditions in Saudi Arabia. Using acetonitrile as the extraction solvent and fourfold dilution in deionized water led to weak signal suppression (<À6.1%). The limits of quantitation ranged from 10 to 40 μg/kg. Mean recovery and relative standard deviation ranged from 81.7 to 96.3% and from 3.6 to 11.4%. The half-lives ranged from 2.22 to 3.83 days, and the dissipation followed first-order kinetics. The terminal residues of myclobutanil, penconazole, tebuconazole, and triadimenol were <0.771, <0.307, <0.459, and <0.954 mg/kg, respectively, 7 days after two or three applications of recommended dosages. The PHIs of 7. 1-11.4, 8.7-13.1, 3.8-5.3, and 11.3-14.3 days are suggested after the application of the recommended dose and double the recommended dose. A consumer risk assessment based on estimated dietary intake indicated that the consumption of squash treated with the recommended doses does not pose a significant health risk. K E Y W O R D S dissipation kinetics, LC-MS/MS, risk assessment, squash, triazole fungicides 1 | INTRODUCTION Squash (Cucurbita sp.)-a rich source of nutrients such as carbohydrates, vitamins, and minerals (Roura et al., 2004)-is a major crop in Saudi Arabia, where the plants are cultivated under open-field and greenhouse conditions (FAOSTAT, 2018). Squash and other cucurbit plants are susceptible to powdery mildew disease, which is mainly caused by the fungus Podosphaera xanthii. In severe cases, powdery mildew can cause premature death of the leaves and reduce squash production over the long term (Velkov & Masheva, 2002).At present, powdery mildew infections of squash leaves are routinely treated with the triazole fungicides myclobutanil, penconazole, tebuconazole, and triadimenol (Figure 1). Triazoles are inhibitors of demethylation that disrupt the biosynthesis of fungal cell

Simultaneous Determination of Seven Pesticides and Metabolite Residues in Litchi and Longan through High-Performance Liquid Chromatography-Tandem Mass Spectrometry with Modified QuEChERS

“…At present, the main detection and analytical methods for the aforementioned pesticides are gas chromatography-electron capture detection (GC-ECD), gas chromatography-mass spectrometry (GC-MS), high-performance liquid chromatography (HPLC), and HPLC-mass spectrometry (HPLC-MS/MS) [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ]. The main matrix includes vegetables such as broccoli and zucchini, fruits such as pears and apples, and traditional Chinese medicine [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ]. Few studies have reported on multiresidue analysis of pesticides and their metabolites in litchi and longan.…”

“…Few studies have reported on multiresidue analysis of pesticides and their metabolites in litchi and longan. Common sample purification methods include solid phase extraction (SPE), liquid–liquid distribution extraction, and QuEChERS [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ]. SPE is a tedious and time-consuming method involving the use of a large amount of organic solvents and nitrogen blowing, which is relatively cumbersome.…”

Dissipation Dynamic And Processing Factor Of Myclobutanil In Tomato

“…It is reported that myclobutanil persists in the environment and accumulates along the food chain, which may threaten human health and environmental pollution (Sun et al 2014). In recent years, there are many reports about the residues of myclobutanil in agricultural products and environmental samples, including the pretreatment method (Deng et al 2010), the dissipation dynamic(Hwang &Kim 2013, Wang et al 2012), the level of myclobutanil residues in the actual samples (Abdallah et al 2021, Lou et al 2008) which has caused public concern.…”

Fungicide dissipation kinetics and dietary exposure risk assessment in squash fruit and leaf

“…However, in the European Union (EU) they are set for squash fruit only(EU Pesticides Database, 2021).The MRL valuesfor squash fruit in the EU and the ROK are 0.5 and 1.5 mg/kg for dimethomorph, 0.3 mg/kg and undetermined for mandipropamid, 0.3 and 0.1 mg/kg for myclobutanil, and 0.01 and 0.2 mg/kg for metalaxyl, respectively.In the case of squash fruit, previous studies reported on dissipation pattern and exposure risk assessment ofchlorfenapyr(Abdel Ghani and Abdallah, 2016),sulfoxa or(O. Abdallah et al, 2021), tebuconazole, penconazole, myclobutnil, and triadimenol(O. I. Abdallah et al, 2021).However, there are no publications on dissipation pattern or human exposure risk assessment of any pesticide in squash leaf.…”

“…Abdallah et al, 2021), tebuconazole, penconazole, myclobutnil, and triadimenol(O. I. Abdallah et al, 2021).However, there are no publications on dissipation pattern or human exposure risk assessment of any pesticide in squash leaf.…”