Residue Safety Evaluation Of Spirotetramat And Its Metabolites In Four Fruits

In this study,the residual detection method of spirotetramat and its four metabolites on hawthorn(Crataegus pinnatifida Bunge.),apricot(Armeniaca vulgaris Lam.),persimmon(Diospyros kaki Thunb.)and pomegranate(Punica granatum L.)were established.After a year of standardized field digestion residue test and standardized field final field residue test,the digestion rule difference of spirotetramat in four fruits was explored,and the difference of the final residue amount of the same fruit in different regions was compared.Long-term and short-term dietary exposures in the general consumer population were assessed to assess the residual safety of spirotetramat in hawthorn,apricot,persimmon,and pomegranate.The results are as follows:(1)QuEChERS combined with high-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)was established to determine the residue of spirotetramat and its four metabolites.Qu ECh ERS method was adopted,and after the sample was extracted with 1% acetic acid-acetonitrile vortex and salted out with sodium chloride,it was purified with graphitized carbon black(GCB)and primary secondary amine(PSA),separated by a chromatographic column,and 0.1% formic acid aqueous solution-acetonitrile mobile phase gradient elution.Under multiple response monitoring mode,it was determined by HPLC-MS/MS,and quantified by the external standard method of matrix matching standard solution.The spirotetramat and its metabolites in hawthorn,apricot,persimmon,and pomegranate showed good linear relationship in the range of 0.005-0.500 mg/L,the correlation coefficients(r)were more than0.98,and the minimum detection concentration was 0.01 mg/kg.When the addition level was 0.01,0.10,1.00 mg/kg,the average recoveries of spirotetramat and its metabolites in Crataegus pinnatifida Bunge were 83%-106%、71%~112%、93%~104% and 74%~100%,and the relative standard deviations(RSDs)were 0.6%-11.0%、0.41%~5.2%、0.8%~4.7% and 0.92%~5.3%.The method is simple and rapid,sensitive and reproducible.It meets the requirements of NY/T 788—2018 Test guidelines for pesticide residues in crops,and is suitable for the determination of spirotetramat and its metabolite residues in hawthorn,apricot,persimmon,and pomegranate.(2)To investigate the differences in the pattern of spirotetramat and its metabolites in hawthorn,apricot and persimmon,the results showed that the half-life of spirotetramat on the three fruits was 12 d,20 d and 30 d,and the digestion dynamics decreased over time.The core data reflect that spirotetramat had the fastest rate of elimination on hawthorn(kernel fruit)and the slowest rate of elimination on persimmon(berry),the digestion rate is hawthorn < apricot < persimmon.Factors such as environmental factors and fruit substrates led to the differences in the digestion rules of spirotetramat in the three fruits to varying degrees.(3)To study the differences in the final residues of spirotetramat in hawthorn,apricot,persimmon and pomegranate in different regions and to compare the residues in different regions of each fruit separately,the results showed that there were differences in the final residues within the same fruit in different regions.(4)Long-term and short-term dietary exposure assessment of spirotetramat in the general consumer population.The results are as follows: the long-term dietary risk probability of spirotetramat in the four fruits is 27.82%,which will not cause health risk to general consumers.The short-term dietary assessment of spirotetramat in apricots,persimmons and pomegranates showed that the final short-term dietary risk probabilities were 0.0252%,1.9467% and 0.1464%,all of which were far less than 100%.affect the health of consumers.