Open AccessOptimized Synthesis of Molecularly Imprinted Hybrid Polymer by Factorial Design for Selective Caffeine Extraction in Surface Water
Author(s) -
Fabiana Casarin,
Camila Santos Dourado,
Luana S. Sousa,
Marco Tadeu Grassi,
Ana Cristi Basile Dias
Publication year - 2021
Publication title -
journal of the brazilian chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.337
H-Index - 70
eISSN - 1678-4790
pISSN - 0103-5053
DOI - 10.21577/0103-5053.20210070
Subject(s) - molecularly imprinted polymer , factorial experiment , chemistry , caffeine , reagent , extraction (chemistry) , theobromine , chromatography , adsorption , solid phase extraction , theophylline , sorbent , selectivity , organic chemistry , catalysis , mathematics , medicine , statistics , endocrinology
A hybrid imprinted polymer (HMIP) was synthetized via sol-gel technique in aqueous solution for caffeine separation from environmental waters samples. The optimal conditions of synthesis were stablished by application of a 23 full factorial experimental design with three factors: ratio of functional monomer and cross-linker reagent, and acid or basic catalyst (HCl or NH4OH). The HMIP obtained with the factorial designs was 22.5 times more selective for caffeine than control polymer, with an adsorption mechanism of pseudo-second order with two sorption sites. The maximum equilibrium adsorption capacity was 1.91 mg g-1 that was maintained until ten cycles of reuse, indicating their excellent stability. The material was 21 times more selective for caffeine than for its analogous molecules (theophylline and theobromine). HMIP was applied in solid phase extraction (SPE) procedure and caffeine extraction of surface water had good recoveries (93.0%).These results demonstrated that the factorial experimental design resulted in an efficient and selective sorbent for caffeine with a reduction of number of synthesis and problems of trial‑and‑error protocol as well as reagents consumption decrease.