DETERMINATION OF PYRACLOSTROBIN RESIDUES IN LEMON FRUIT AND LEMON ESSENTIAL OIL

MARÍA EUGENIA NAVARRO; KAMIYA, NORMA; AGUILAR LORETTO, SOLANA; ROJAS, ALEJANDRO; ALVA, MARIANA; LACINA, MARINA; FOGLIATA, GABRIELA

Foz do Iguazu

Workshop; 7º Latin American Pesticide Residue Workshop; 2019

UFSM

DETERMINATION OF PYRACLOSTROBIN RESIDUES IN LEMON FRUIT AND LEMON ESSENTIAL OIL Mariana Alva1, María E. Navarro1, Solana Aguilar Loretto, Marina Lacina1, Norma Kamiya1, Alejandro Rojas2, Gabriela M. Fogliata21Laboratorio de Residuos de Plaguicidas (LRP), Sección Química, Estación Experimental Obispo Colombres (EEAOC), Av. W. Cross 3150, Las Talitas, CP 4101, Tucumán, Argentina E-mail: plaguicidas@eeaoc.org.ar2Sección Fitopatología, Estación Experimental Obispo Colombres (EEAOC), Av. W. Cross 3150, Las Talitas, CP 4101, Tucumán, Argentina Tucuman province (Argentina) is the worldwide leader in production of lemon and its byproducts like juice and lemon essential oil (LEO). The last one is used as scent in beverages, food, perfumes and medicine. Residues of pesticides applied on lemon trees can be found in this oil in concentrated contents as compared to the fruit, on account of the extraction and concentration procedures that are conventionally followed. Pyraclostrobin is one of the most frequently pesticide used for fungal diseases.This work aimed to show the correlation about pyraclostrobin residues found in lemon fresh fruit and LEO extracted of the same fruits.A volume of 1 l/ha of a commercial product with 25% concentration of active ingredient was applied on Lisbon lemon adults trees, in once (november, december and january) or twice (november- december, november-january, december-january) at different moments during the infection period.The harvest was done in two moments, april and june, and with this samples the extraction of the essential lemon oil was done in the laboratory with a laboratory scale extractor machine.The fresh fruit was processed by QuEChERS AOAC 2007.01 [1] and liquid-solid dispersion with Mg2SO4, NaCl and acetonitrile was used for extracting 5 g of LEO, followed by clean up with PSA and C18, method based on Anastassiades et al. [2] and Agilent modified QuEChERS EN Application Note [3]. In order to quantify and confirm pyraclostrobin by liquid chromatography, a Shimadzu Nexera liquid chromatograph with an ABSciex triple quadrupole 5500 detector was used.The results obtained are shown in Table Nº 1. Table Nº 1:Number of applicationsHarvest monthPyraclostrobin range (mg/kg)Fresh fruitLEO1April0.01 - 0.031.0 - 3.0June0.01 - 0.021.0 - 3.02April0.04 - 0.062.0 - 5.0June0.02 - 0.032.0 - 4.0In general, greater concentrations of residue were observed also in fresh fruit and LEO when 2 applications were made. The concentration of Pyraclostrobin in LEO was around 100 fold greater compared with fresh fruit. [1] Pesticide Residues in Foods by Acetonitrile Extraction and Partitioning with Magnesium Sulfate, AOAC Official Method 2007.01[2] Anastassiades, M., Lehotay, S.J., Stajnbaher, D., Schenck, F.J. Fast and easy multiresidue method employing acetonitrile extraction/partitioning and "dispersive solid-phase extraction" for the determination of pesticide residues in produce. 2003. J AOAC Int., 86(2):412-31.[3] Zhao, L., Stevens, J. Determination of Pesticides in Lemon Oil via Modified Agilent Bond Elut QuEChERS Method, Application Note, Agilent Technologies.