Decline patterns and risk assessment of 10 multi-class pesticides in young sprout amaranth (Amaranthus mangostanus) under greenhouse growing conditions

Abstract

The present study was designed to investigate the residual decline pattern and the risk assessment of 10 different class pesticides, namely azoxystrobin, boscalid, diazinon, diethofencarb, difenoconazole, etofenprox, flubendiamide, paclobutrazol, and pyraclostrobin in young vegetative amaranth (Amaranthus mangostanus) sprayed once or twice under greenhouse growing conditions. Field-incurred samples, collected at 3, 7, or 10 days after application of both treatments, were extracted and purified with the quick, easy, cheap, effective, rugged, and safe "QuEChERS" citrate-buffered method and analyzed with liquid chromatography-electrospray ionization tandem mass spectrometry (LC-MS/MS) in positive ion mode. The linearity was satisfactory with determination coefficients (R ) falling between 0.9817 and 0.9999 and limits of detection (LOD) and quantification (LOQ) values of 0.0007 and 0.002 mg/kg, respectively. The mean recovery rate at four spiking levels (equivalent to 5, 10, 50, and 100 × LOQ) ranged from 78.1 to 131.6% with a relative standard deviation (RSD) of< 11%. Substantial differences in the initial deposit between the tested analytes were observed and clearly indicated that the structure, as well as the initial concentration of applied products, greatly affected the residue deposit. From the obtained residual data, the provisional marginal maximum residue limits (MRLs) and the pre-harvest intervals (PHI) were proposed. Risk assessment was evaluated by comparing the theoretical maximum daily intake (TMDI) with the acceptable daily intake (ADI). Herein, the TMDI was lower than the ADI (TMDI/ADI ratio ≤ 80% set by the Korean Ministry of Food and Drug Safety) except for difenoconazole (80.92%, marginally higher), indicating that the vegetative amaranth is not hazardous and can be consumed safely by Korean consumers.

Residues and Safety Assessment of Cyantraniliprole and Indoxacarb in Wild Garlic (Allium vineale)

“…Indoxacarb’s higher initial residues were attributed to the high amount of active ingredient in the commercial formulation. These findings agree with the results of previous studies that reported that the initial residues of pesticides in crops depend on various factors (formulation, active ingredient, type of crop, dilution factor, and physicochemical properties of pesticides) [ 3 , 17 , 21 ]. In the case of indoxacarb, the log P value was higher than that of cyantraniliprole, which is considered to easily penetrate the crop, leading to higher residues [ 22 ].…”

“…If crops do not provide sufficient financial payback, pesticide companies are unwilling to undertake expensive research to register pesticides for them; there will therefore be fewer options for the protection of such crops against pests [ 2 ]. In such cases, growers who cultivate minor crops apply non-registered pesticides to control pests [ 3 ]. The presence of non-registered pesticide residues in crops is of significant concern to consumers due to their health risks [ 4 ].…”

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

“…These findings agree with previous studies in the context that the initial residues of pesticides in crops depend on several factors such as the active ingredient (AI), formulation, dilution factor, and type of crop 13 . The AI used in this study was spiromesifen SC 20% and chromafenozide EC 5%, it may be assumed that the higher initial residues of spiromesifen are due to the high concentration of AI present in the formulation products 4 . Pesticide formulation has major effects on its penetration through the leaf surface and dissipation.…”

“…Pesticide formulation has major effects on its penetration through the leaf surface and dissipation. Generally, SC formulations retained better than wettable powder (WP) form 4 . The insecticide formulations used in the current study were spiromesifen SC and chromafenozide EC, which are considered to have good adhesion and easy penetration into the crops contributing to high initial residues 14 .…”

“…In general, minor crops do not provide an adequate economic return for pesticide manufacturers to justify the cost of registration 3 . As a result, farmers who grow minor crops, use the existing or unregistered pesticides for pest control 4 . Further, unregistered pesticide residues in crops are of great concern due to their potential health risk 5 .…”