Abstract
OBJECTIVE: Development of highly sensitive analytical methods for the determination of carbamate pesticides.
CONCLUSIONS:
- Interaction between S (carbamate pesticides, promecarb (PC) and bendiocarb BC)) and CD (cyclodextrin) or HPCD (hydroxypropyl-CD) was observed by spectrofluorimetry. They form complexes with 1:1 stoichiometry.
- KAPC / KABC as KA alkyl >> KAaryl (KA = association constant).
- fSCD/ fS >>1 higher analytical sensitivity in the presence of CDs (fSCD/ fS = fluorescence quantum yield ratio).
- The use of CDs as fluorescence modifiers provides a good alternative to replace organic solvents as %IFs indicate.
- LOD determined by CDs fluorescence enhancement are similar to literature values by other methods.
*PC: 0.085 mg mL-1 chemiluminiscence determination by FIA using photochemical reactions (Analyst, 2002, 127, 1526-1530) equivalent to 0.094 mg mL-1 as IUPAC currently recommend.
*BC: 0.022 mg mL-1 with S/R = 3 in acetonitrile by FIA using fluorescence detection (Analusis, 1996, 24, 107-112) equivalent to 0.185 mg mL-1 IUPAC definition, in acetonitrile under our experimental conditions.
- Application to the analysis of spiked tap water, fruit sample and powder pesticide formulation yield acceptable recoveries (70-115%) as are stated by international regulatory agencies.
- The proposed method is rapid, simple, direct, sensitive and useful for carbamate pesticide analysis.
