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

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.