Application Of NMR Method In Analysis Of Cyflumetofen And Metaflumizone

In this paper,a ¹⁹F-NMR quantitative detection method with simple pre treatment and fast and accurate detection was established to reduce the burden of th e tedious pretreatment steps in the quantitative analysis of pesticides.The experimen t used BRUKER AVANCE HD 600 superconducting Fourier transform NMR spectr ometer,5mm BBO probe,observation frequency 564.71MHz,spectral width（SWH）was 170454.55Hz,center frequency（O1P）-56471.40Hz,90 degree pulse width 15.11μs With sampling temperature（T）of 25°C,delay time（D1）of 10s,and sampling ti mes（NS）of 64 times,different p H values,different Ti O₂concentrations and differe nt H₂O₂ concentrations were investigated for cyflumetofen and metaflumizone.The d ynamic degradation of flubendix in water and its degradation history.Using ¹⁹F-NMR method,using water and analytically pure acetone as solvent,t rifluoromethoxyaniline was used as internal standard,deuterated acetone was placed i n a small cannula for lock field,and the sample was recorded under 64 scan times.Fluorescence spectrum.The effects of different p H values,different Ti O₂ concentrat ions and different H₂O₂ concentrations on the hydrolysis of cyflumetofen under light were investigated experimentally.The results show that in the presence of light,cy flumetofen is stable under acidic conditions,and its degradation is accelerated with t he increase of p H.It is easier to hydrolyze under neutral to alkaline conditions,esp ecially alkaline conditions.The lower end is easily hydrolyzed,and the addition of hydrogen peroxide and titanium dioxide promotes the degradation of butyrate,and th e degradation rate increases with the increase of the dosage.Under most conditions,the remaining cyflumetofen could not be accurately quantified at 35-49d,indicating that cyflumetofen is more susceptible to degradation.Using ¹⁹F-NMR method,water and reagent pure acetone as solvent,trifluorometh oxyaniline as internal standard,deuterated acetone into small sleeve for lock field,r ecord sample under 64 scan times Fluorescence spectrum.The effects of different p H values,different Ti O₂ concentrations and different H₂O₂ concentrations on the hyd rolysis of metaflumizone in the light were studied experimentally.The results showe d that in the presence of light,metaflumizone was easily hydrolyzed under acidic to alkaline conditions,and it was relatively stable under neutral conditions,but the ha lf-life was also shorter.Hydrogen peroxide and titanium dioxide were added.Both o f them promoted the degradation of metaflumizone,and with the increase of dosage,the degradation rate was significantly accelerated,and the half-life ranged from less than 1d to 1.28d.At 10 days,the residual concentration did not meet the limit of quantitation and could not be quantified.It can be seen that metaflumizone is a hi ghly degradable pesticide.The experiment uses ¹⁹F-ASSURE for T₁ measurement,and the pulse program selects t1irpg.In this experiment,the inversion recovery-flip gated decoupling experi ment method is used to measure T₁.Compared with the inversion gate method,the inversion recovery-flip gate is performed.The coupling experiment method lengthens the delay time and the interval between pulses,which can suppress the NOE effect to a certain extent and make the quantitative experiment more accurate.The experi ment used two-dimensional mode for one-dimensional detection,and the experiment was carried out with 0.05s,0.10 s,0.5 s,1 s,3 s,6 s,10 s,16 s,24 s,50 s as the delay time.T₁ fit curve of cyflumetofen and metaflumizone.According to the a nalysis,the T₁ of the fluorine nucleus of butaflurane is 1.445s,and the relaxation ti me of the two fluorine nucleus of metaflumizone is 1.444s and 1.094s,respectively,corresponding to trifluoromethyl and trifluoromethoxy where two fluorine atoms on it.The structure of cyflumetofen and metaflumizone was identified by infrared s pectroscopy,ultraviolet spectroscopy,high resolution mass spectrometry and nuclear magnetic resonance spectroscopy.Hydrogen spectroscopy（¹H-NMR）,carbon spectr oscopy(¹³C-NMR),undistorted polarization transfer enhancement（DEPT）and ¹H-¹H homonuclear displacement correlation spectrum（COSY）in 2D,¹H-¹³C Heteronu clear single quantum correlation spectroscopy（HSQC）,¹H-¹³C heteronuclear multi-b ond correlation spectroscopy（HMBC）and ultraviolet absorption spectroscopy（UV）,infrared absorption spectroscopy（IR）,and high resolution mass spectrometry（HR-MS）were analyzed.The vibrational forms of the functional groups corresponding t o the infrared characteristic absorption peaks were assigned to the ¹H and ¹³C NM R signals,and the positions of the related groups in the figure and the order of t heir connections were identified to confirm the structure of the compound.The co nfirmation of information and structure of spectroscopy is very important for the q uality control of pesticide production process,and provides a reference for the syn thesis of the same type of substances.It will also develop,apply and analyze the determination and application of butyrate and its analogues.A reference is provid ed for identifying other by-products in the synthesis process.The degradation products of butaflurane and cyanofluorfen were isolated and purified,and the degradation product2-（4-（tert-butyl）phenyl）-3-hydroxy-3-（2-（trifluoro methyl）phenyl）acrylonitrile of butyl fluoride ester and the degradation product 4-（2-oxo-2-（3-（trifluoromethyl）phenyl）ethyl）benzonitrile of cyanofluorfen were obtained.T heir structures were identified by mass spectrometry and nuclear magnetic resonanc e.The possible degradation pathways were analyzed.