Application Of Resonance Light Scattering In The Determination Of Pesticides Residues And Food Additives

Resonance Light Scattering(RLS)is one kind of sensitive and simple analysis technology developing in recent years.This law to pellet size extremely keen, therefore the sensitivity is extremely high,may reach the nanogram level,is the general analysis method difficulty with compares.And RLS can detect solution of non-color change or non-fluorescence change response,thus expanded the biological probe scope,also only need the ordinary fluorescence spectrophotometer,adds it to operate easy,therefore develops in recent years extremely rapidly.There have been more reports of this technology using in big molecule of living things such as protein and nucleic acid.In quantitative analysis aspect of polysaccharide,inorganic ion, organic matter,certain medicines and so on,also has made a better progress,but,this kind of technology applied to the agricultural chemicals and the food additive residual examination is unusually reported.Resonance Light Scattering,Dual Wavelength Resonance Light Scattering Ratiometry,the Chemometrics technology applied to certain pesticides and the food additives quantitative determination are researched in this article.It has been applied to the determination of the real samples with satisfactory results.1.A new method of determination of fenvalerate is investigated by RLS, detecting the spectral characteristics of RLS for chromotrope 2R- fenvalerate-β-CD system and optimizing the response condition.In the Britton-Robinson buffer solution of pH2.87,the interaction of ehromotrope 2R with fenvalerate results in enhanced RLS signals at 423 nm,and the interaction was sensitized by theβ-CD.The RLS intensity is proportional to the concentration of fenvalerate.The linear range is 0.02～0.50μg/mL,the limit of detection is 0.016μg/mL.The method is simple,rapid and sensitive.It has been applied to the determination of fenvalerate in the real samples.2.A new method of determination of rudimental prometryne is built.The interaction between bromocresol green and prometryne acidulated with HCl results in enhancing RLS signals at 562 nm,and the interaction was serisitized by the Triton X-100.The RLS intensity is proportional to the concentration of prometryne.The linear range is 0.01～0.35μg/mL,the limit of detection is 7.8 ng/mL.The method is simple,rapid and sensitive.It has been applied to the determination of prometryne in the real samples successfully.3.Had established a Dual Wavelength Resonance Light Scattering Ratiometry technology for the food additive Amaranth and the Methyl violet mutual affects and the analysis examination,including the suitable conditions,influencing factors,and the application of this method,and were compared to single-wavelength resonance light scattering method.The interaction between Methyl violet and Amaranth in the pH1.24 results in enhancing RLS signals at 528nm,and the interaction was sensitized by the Triton X-100.The RLS intensity is proportional to the concentration of prometryne.The linear range is 0.05～0.50μg/mL,the limit of detection is 0.0204μg/mL.The resonance light scattering ratiometry I₄₁₇/I₃₄₃of 417nm and 343nm was instead of single-wavelength resonance light scattering method to detect Amaranth.The linear range is 0.01～0.60μg/mL,the limit of detection is 0.001μg/mL. From this study,Resonance Light Scattering Dual Wavelength Ratiometry is more suitable to detect Amaranth for its better stability,broader linear range of detection and lower detection limits than single wavelength resonance light scattering method.4.A dual-wavelength resonance lighting scattering ratiometry was constructed to detect CPB.In the pH1.5 controlled medium,CPB could interact with Bromothymol blue,displaying significantly enhanced RLS signals.By measuring the RLS signals characterized at 523nm and the RLS intensity ratio(I₂₄₈/I₄₂₄),respectively,CPB over a wide dynamic range of content could be detected.Using single-wavelength resonance light scattering method could detect CPB over the range of 0.05～0.60μg/mL with the limit of 0.0416μg/mL,while using dual-wavelength resonance lighting scattering ratiometry could detect CPB over the range of 0.03～1.0μg/mL with the limit of 0.003μg/mL.And in comparison with RLS method,this dual-wavelength resonance lighting scattering ratiometry is less affected by environmental conditions such as pH,ionic strength.Thus the latter is obviously superior to the former one. 5.A spectrophotometric method for simultaneous determination of six herbicides has been investigated and developed.The absorption spectra of six herbicides(trietazine,atrazine,simetryne,diuron,fenuron and propanil)are overlapped seriously in a B-R buffer solution(pH 5.0),and quantitative estimations can not be carried out successfully without a pre-separation.In the research introduced the principal components regression(PCR)and partial least squares(PLS) and other Chemometrics methods,optimized the adjustment model,and successfully applied to resolve the overlapped seriously absorption spectra of six herbicides mixtures.