Dissipation of spiromesifen and spiromesifen-enol on tomato fruit, tomato leaf, and soil under field and controlled environmental conditions

Abstract

Dissipation of spiromesifen and its metabolite, spiromesifen-enol, on tomato fruit, tomato leaf, and soil was studied in the open field and controlled environmental conditions. Sample preparation was carried out by QuEChERS method and analysis using LC-MS/MS. Method validation for analysis of the compounds was carried out as per "single laboratory method validation guidelines." Method validation studies gave satisfactory recoveries for spiromesifen and spiromesifen-enol (71.59-105.3%) with relative standard deviation (RSD) < 20%. LOD and LOQ of the method were 0.0015 μg mL and 0.005 mg kg, respectively. Spiromesifen residues on tomato fruits were 0.855 and 1.545 mg kg in open field and 0.976 and 1.670 mg kg under polyhouse condition, from treatments at the standard and double doses of 125 and 250 g a.i. ha, respectively. On tomato leaves, the residues were 5.64 and 8.226 mg kg in open field and 6.874 and 10.187 mg kg in the polyhouse. In soil, the residues were 0.532 and 1.032 mg kg and 0.486 and 0.925 mg kg under open field and polyhouse conditions, respectively. The half-life of degradation of spiromesifen on tomato fruit was 6-6.5 days in the open field and 8.1-9.3 days in the polyhouse. On tomato leaves, it was 7-7.6 and 17.6-18.4 days and in soil 5.6-7.4 and 8.4-9.5 days, respectively. Metabolite, spiromesifen-enol, was not detected in any of the sample throughout the study period. Photodegradation could be the major route for dissipation of spiromesifen in the tomato leaves, whereas in the fruits, it may be the combination of photodegradation and dilution due to fruit growth. The results of the study can be utilized for application of spiromesifen in plant protection of tomato crop under protected environmental conditions.

Residue Evaluation of Spiromesifen in Tomato fruits, Leaves, and Soil in Baghdad-Iraq using QuEChERS Extraction via FID-Gas Chromatography

“…The concentrations of these residues at the detected levels were determined to be below the established Maximum Residue Limit (MRL) at 1 mg/kg, as reported in the European Union MRL database (European Food Safety Authority 2012). Al-Mashhadany et al (2012) came to the same conclusions, so the above data are in line with them [30], who determined that spiromesifen residue in cucumber, which was 11.63 mg/kg following treatment, was reduced to MRL within 7 days (i.e. 0.19 mg/kg).…”

“…Sharma et al (2014) analysed spiromesifen residues has been performed on tomatoes by multistep, high organic solvent volume using gas chromatography (GC)-mass spectrometry (MS). Moreover, the behaviour on tomato leaves, tomato fruits, and eld soil of spiromesifen has been analysed using liquid chromatography (LC)-MS/MS in an open area and controlled environmental conditions studied (Siddamallaiah et al 2017). Pesticide residues may accumulate at higher levels than those permitted by European Union (EU) regulations or international maximum residue limits (MRLs), given the intensive use of pesticides in greenhouse crops.…”

Residual characteristics and safety assessment of the insecticides spiromesifen and chromafenozide in lettuce and perilla

“… 8 . It controls the growth of larva through the inhibition of the lipid metabolism enzyme (acetyl CoA-carboxylase) and causes a significant decrease in the lipids 9 . In addition, it does not show cross-resistance against mites and whiteflies, and thus has excellent insecticidal efficacy against insects 10 .…”

Terminal Residues and Risk Assessment of Spiromesifen and Spirodiclofen in Tomato Fruits

“…For spiromesifen, the current results were roughly comparable with half-lives of 0.93–1.38 days for tomato [ 30 ], 1.6, 1.8, 1.9, and 1.7 days for okra, bell pepper, chili, and brinjal, respectively [ 31 ], and 1.32–2.18 days for brinjal [ 32 ]. In contrast, a few reports have investigated the longer half-life of spiromesifen in different crops: 5.5–6.2 days, 2.52–2.88 days, and 5.0–8.5 days in apple, eggplant, and leaf tea, respectively [ 13 , 33 , 34 , 35 ], and 6–6.5 days in tomato [ 14 ]. For spirodiclofen, on the other hand, little data are available on crop dissipation kinetics.…”

“…Spiromesifen [2-oxo-3-(2,4,6-trimethylphenyl)-1-oxaspiro[4.4]non-3-en-4-yl-3,3-dimethylbutanoate] and spirodiclofen [3-(2,4-dichlorophenyl)-2-oxo-1-oxaspiro[4.5]dec-3-en-4-yl-2,2-dimethylbutyrate] ( Figure 1 a,b) are novel insecticides that fall into the category of spirocyclic phenyl-substituted tetronic acid derivatives and act as acetyl-coenzyme carboxylase (ACCase) inhibitors by disrupting lipid biosynthesis at all developmental stages of mites that infest tomatoes, chili, eggplant, cotton, and other crops [ 9 ]. Because spiromesifen and spirodiclofen are relatively new insecticides/acaricides, few data are available on residues and rates of dissipation in vegetables and fruits under field conditions: chili [ 10 ], okra [ 11 ], cabbage [ 12 ], eggplant [ 13 ], tomatoes [ 14 ], and citrus [ 15 , 16 ].…”