Study On Detection Methods Of Imidacloprid And Acetamiprid In Instant Tea And Macroporous Degradation

There used to be a excess problem of imidacloprid and acetamiprid in instant tea when instant tea export. In this paper, different types of macroporous resins were used to adsorb imidacloprid and acetamiprid added into instant tea solution, and then selected macroreticular resin which adsorbed more imidacloprid and acetamiprid and less tea polyphenols and caffeine of instant tea, for the purpose of finding macroporous resin's degradation technology of imidacloprid and acetamiprid in instant tea.In this paper, pre-treatment methods of imidacloprid's and acetamiprid's detection in instant tea were studied. Detection of imidacloprid and acetamiprid in instant tea was in accordance with the "GB/T 23379-2009 fruits, vegetables and tea in the determination of imidacloprid residues in High Performance Liquid Chromatography", by adding 2mg/kg of imidacloprid and acetamiprid standard products into instant tea for recoverys tests, but the results of imidacloprid's and acetamiprid's recoveries were only 1.1-1.7% and 5.1-6.6%, bias was largely because of the flawed sample's pre-treatment methods, then tried to extract the imidacloprid and acetamiprid in the instant tea with water firstly, followed by extracting with organic solvents acetonitrile, and then decontaminated before treatment. This method was adding 2mg/kg of imidacloprid and acetamiprid standard products into instant tea for the recoverys, and the results were respectively91.4-94.3% and 92.9-94.4%, also the standard deviation was less than 10%, which consistents with pesticide residue's analysis, The method's limits of quantification was 0.01mg/kg, accoring with detection of imidacloprid and acetamiprid in instant tea.In this paper, methods of adsorbing imidacloprid and acetamiprid in instant tea by macroporous resin were studied. Seven macroporous resins were used to adsorb staticly imidacloprid in instant tea, through that to study the the absorptions of imidacloprid and tea polyphenols and caffeine in instant tea, then used the DPS software to analyse the data of macroporous resins'adsorption, the results showed DA-201CII had a good staticly adsorption, followed by this macroporous resin's dynamic adsorption, designed three factors of instant tea's solution that was flow rate, concentration and pH value, throurgh this three factors of single-factor tests to obtain better conditions for the adsorption: the flow rate was 3mL/min, the concentration was 120g/L, pH value was 5.0; Seven macroporous resins were used to adsorb staticly acetamiprid in instant tea, through that to study the the absorptions of acetamiprid and tea polyphenols and caffeine in instant tea, ,through the data analysis of resins's adsorption, it found that two kinds of instant tea samples adsorbed by LS-803 and XAD-16 arise a large interference when detecting, that leaded unable to quantify, in other samples, XDA-8 resin's adsorption represented a good effect, but the resin was the lowest static resolution rate that was only 54.60%,and it had a larger adsorption of tea polyphenols and caffeine in instant tea, so there was no choice of resin to carry out dynamic adsorption of acetamiprid in instant tea,and the experimention needed to study in the future.