A selective spectrofluorimetric method for carbendazim determination in oranges involving inclusion-complex formation with cucurbit[7]uril.
The increase in fluorescence intensity with respect to carbendazim that occurs as a result of supramolecular-complex formation between carbendazim and cucurbit[7]uril has been studied. This host-guest interaction has been employed to develop a sensitive and selective method for benzoimidazole-type pesticide determination in fruit samples. The association constant and stoichiometry of the complex formed are reported herein, and the influence of experimental variables, such as the pH or ionic strength of the solution, on complex formation and the presence of interfering substances is also discussed. Under the optimal conditions found, the developed method allows the detection of carbendazim at a 5.0x10(-9)M level. To test the method, matrix solid phase dispersion was employed as a sample preparation method for carbendazim determination in orange samples with an RSD (%) (n=3) value of 5%. The LOD and LOQ values calculated for real samples were 0.10 and 0.52mg/kg, respectively, thus showing that the proposed method is sensitive enough to meet legal requirements.
del Pozo
M
M
Dpto. Química Analítica y Análisis Instrumental, Facultad de Ciencias, Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain.
Hernández
L
L
Quintana
C
C
D001562:Benzimidazoles / Q000032:analysis; D001952:Bridged-Ring Compounds / Q000032:analysis*; D002219:Carbamates / Q000032:analysis; D002623:Chemistry Techniques, Analytical; D032084:Citrus sinensis / Q000378:metabolism*; D005504:Food Analysis / Q000379:methods*; D005506:Food Contamination; D006863:Hydrogen-Ion Concentration; D007093:Imidazoles / Q000032:analysis*; D007477:Ions; D057230:Limit of Detection; D008968:Molecular Conformation; D010573:Pesticide Residues / Q000032:analysis; D010575:Pesticides / Q000032:analysis; D015203:Reproducibility of Results; D013050:Spectrometry, Fluorescence / Q000379:methods*; D047028:Macrocyclic Compounds; D000099246:Cucurbit(n)urils
D001562:Benzimidazoles; D001952:Bridged-Ring Compounds; D002219:Carbamates; D007093:Imidazoles; D007477:Ions; D010573:Pesticide Residues; D010575:Pesticides; C456276:cucurbit(7)uril; D047028:Macrocyclic Compounds; D000099246:Cucurbit(n)urils; C006698:carbendazim