Determination of the dissipative behaviour and final residue of sodium nitrophenol in jujube by liquid chromatography–tandem mass spectrometry

Abstract

Through field trials and residue analysis, the dissipation behaviour and final residue levels of sodium nitrophenol on jujube were clarified to provide a basis for its safe application and the development of maximum residue limits. The samples were extracted with acetonitrile, cleaned up by a hydrophilic-lipophilic balanced solid-phase extraction column, determined by ultra-high LC-tandem mass spectrometry and quantified by the external standard method. The mean recoveries of sodium 5-nitroguaiacolate, sodium o-nitrophenol and sodium p-nitrophenol were 88.9%-103.8%, with relative standard deviations less than 13.6% at 0.002-0.2 mg/kg spiked levels. Sodium nitrophenol in jujube was dissipated according to the first-order kinetic equation with half-lives of 12.7-17.4 days. At a harvesting interval of 7 days, the residues of sodium nitrophenol in jujube were lower than the limit of 0.03 mg/kg established by the European Food Safety Authority. Residues of jujube were acceptable at a harvest interval of 7 days when sodium nitrophenol was sprayed twice at 9.0 mg/kg with an interval of 7 days. Therefore, the safety interval for sodium nitrophenol application on jujube can be set as 7 days.