Document Type : Research Paper

Authors

• Vahideh Mahdavi ¹
• Aziz Sheikhigarjan ²
• Mohammad Taghi Tohidi ³
• Leila Faraverdeh ⁴
• Mohammad Nateq Golestan ⁵
• Abdoolnabi Bagheri ⁶

¹ Pesticide Research Department, Iranian Research Institute of Plant Protection (IRIPP),, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran.

² Department of Agricultural Entomology, Iranian Research Institute of Plant Protection, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran.

³ Department of Plant Protection, Agriculture and Natural Resources Research and Education Center in Kermanshah Province, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran

⁴ Department of Pesticides Research, Iranian Research Institute of Plant Protection, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran

⁵ Plant Protection Research Department, Khorasan Razavi Agricultural and Natural Resources Research Center, Agricultural Research, Education and Extension Organization (AREEO), Mashhad, Iran.

⁶ Department of Plant Protection, Agriculture and Natural Resources Research and Education Center in Hormozgan Province, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran

Abstract

Keywords

• Pesticide Residue
• Pre-harvest Interval
• Tomato
• Tomato Fruit Worm

Extended Abstract

Introduction

 Objective

       Over the past few years, food safety has gained significant prominence. The presence of pesticide residues stemming from applying synthetic plant protection agents in fruit cultivation has become a significant apprehension for consumers, particularly children, due to their detrimental impacts. The ingestion of fruits in their natural state, or their processed derivatives containing pesticide residues that exceed the permissible limits, can pose a substantial risk to human health. Because pesticide treatment leads to its accumulation in fresh tomatoes, it is challenging to successfully bring the vegetables to the market within the restricted and safe timeframe that adheres to the residue-level regulations. Therefore, tomatoes, which are usually consumed fresh, have faced increased scrutiny in the past few years due to their potential dietary risks and have emerged as a considerable issue in terms of both food safety and compliance with trade standards.

With a per capita consumption of more than 30 kilograms per year, tomatoes constitute a major share of the household food basket, so the health of this product has a significant impact on the health of the household food basket. Currently, the tomato fruit worm or cotton bollworm Helicoverpa armigera, with a wide host range, is one of the key pests of tomatoes, which has reduced the marketability of this product, and chemical control of this pest is one of the common methods of managing this pest.

Materials and Methods

     In this study, Certified Reference materials (CRMs), acetonitrile, and Poly Secondary Amin (PSA) were purchased from Sigma-Aldrich, Scharlau (Barcelona, Spain), and Agilent company (USA), respectively.  The evaluation of the pre-harvest interval (PHI) was carried out at the optimal doses of each of the studied pesticides. Alverd^@ 240 SC insecticide at a dose of 1000 ml/ha and Proclaim Fit^@ UV 500 WG insecticide at a dose of 100 g/ha showed the best efficiency. Therefore, the residue of these pesticides in tomato crops and the evaluation of the proposed pre-harvest interval were carried out at these doses. A quick, easy, cheap, effective, rugged, and safe (QuEChERS)-based sample preparation method coupled with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) in dynamic multiple reaction monitoring (dMRM) mode was developed to determine the residues of the 3 pesticides in treated tomato samples. SB-C18, Zorbax Eclipse column for separation of pesticides and acetonitrile with formic acid in water as mobile phase was used, respectively.

Results and discussion

    The process was validated, and the linear dynamic range (LDR) of the matrix-matched calibration curves was 0.005–0.5 mg/kg, with determination coefficients (R²) greater than 0.99. The limits of detection (LOD) and quantification (LOQ) of the method were in the range of 0.001–0.004 mg/kg and 0.005–0.01 mg/kg, respectively. Furthermore, accuracy and precision were studied at two concentration levels. The recoveries were 71–110%, and relative standard deviations (RSD%) for the three replicates were lower than 17.8% for all analytes. The developed method was applied to tomato-treated samples collected from Kermanshah province, and three pesticide residues were found at concentration levels lower than maximum residue limits (MRLs). Based on the results of the insecticide residues of metaflumizone, lufenuron, and emamectin benzoate in tomatoes treated with these pesticides, the 3-day pre-harvest interval of Alvord (metaflumizone) and the 7-day pre-harvest interval of Proclaim Fit (lufenuron and emamectin benzoate) were investigated and verified.

Conclusions

    The residue results, compared to the national MRL of these pesticides, showed that the 3-day PHI of metaflumizone and the 7-day PHI of lufenuron and emamectin benzoate in tomatoes were acceptable. Based on the results, the following recommendations are offered:

• Use of registered pesticides
• Use of pesticides at an appropriate time
• Use of pesticides in appropriate doses and concentrations, with recommended spraying intervals
• Use of appropriate spraying methods (appropriate to the type of pesticide, target pest, host, and production space)
• Avoid using unauthorized, counterfeit, unknown, suspicious, and poorly qualified pesticides
• Compliance with the expiration date of pesticides and paying attention to the warnings on pesticide labels
• More practical supervision for the import, production, and packaging of agricultural pesticides
• To avoid frequent use of pesticides with a high probability of developing resistant populations of pests (in this regard, to pay attention to the grouping of fungicides and insecticides with the resistance risks in FRAC and IRAC tables, respectively.)