Inclusion Complex of o-Phthalaldehyde-Metolachlor with Cyclodextrins Using the Thermochemically-Induced Fluorescence Derivatization (TIFD) Method and Its Analytical Application in Waters.
A thermochemically-induced fluorescence derivatization (TIFD) method for the determination of metolachlor (MET) based on the o-phthalaldehyde thermo product complex of MET (OPA-MET) enhanced with either hydroxypropyl-?-CD (HP-?-CD) or dimethyl-?-CD (DM-?-CD) was investigated. The analytical conditions of the TIFD method were the same for the complexes, except for the solvent. The fluorescence enhancement was highlighted for the OPA-MET complex in the presence of cyclodextrins (CDs). Besides the stability of the OPA-MET:CD inclusion complexes, which corroborates the reproductibility of the TIFD method, a 1:1 stoichiometric ratio between OPA-MET was obtained in both of the organized environments (CDs). The binding constants (K1) of the inclusion complexes OPA-MET: HP-?-CD and OPA-MET: DM-?-CD of 1:1 type are (264?±?36) L·mol?1 and (173?±?17) L·mol?1, respectively. Under the optimal conditions, the linear dynamic range of the TIFD method is 10–580 ng·mL?1 and correlation coefficients obtained through calibration curves were close to unity. Limits of detection (LODs) and quantification (LOQs) are in the ranges 0.06–0.09 ng·mL?1 and 0.2–0.3 ng·mL?1, respectively. A solid phase extraction (SPE) procedure successfully combined with the TIFD method in the presence of cyclodextrins, for quantitative analysis of samples spiked with metolachlor, led to satisfactorly accurate values (recovery: 92.2–121% and RSD: 1.1–1.3%).
Auteur(s) : Alphonse Mendy, Diène Diégane Thiaré, Ibrahima Sarr, El. Hadji Tombé Bodian, Souleymane Sambou, Mame Diabou Gaye-Seye, Atanasse Coly, Alphonse Tine
Pages : 502-514
Année de publication : 2019
Revue : Journal of Solution Chemistry
N° de volume : 48
Type : Article
Mise en ligne par : COLY Atanasse