Acceso AbiertoDevelopment of an ionic-liquid-based dispersive liquid–liquid microextraction method for the determination of antichagasic drugs in human breast milk. Optimization by central composite design(2015) Padró, Juan Manuel; Pellegrino Vidal, Rocío; Echevarria, Romina Noel; Califano, Alicia N.; Reta, Mario RobertoChagas disease constitutes a major public health problem in Latin America. Human breast milk is a biological sample of great importance for the analysis of therapeutic drugs, as unwanted exposure through breast milk could result in pharmacological effects in the nursing infant. Thus, the goal of breast milk drug analysis is to inquire to which extent a neonate may be exposed to a drug during lactation. In this work, we developed an analytical technique to quantify benznidazole and nifurtimox (the two antichagasic drugs currently available for the medical treatment) in human breast milk, with a simple sample pre-treatment followed by an ionic-liquid-based dispersive liquid–liquid microextraction combined with high-performance liquid chromatography and UV detection. For this technique, the ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate has been used as the “extraction solvent”. A central composite design was used to find the optimum values for the significant variables affecting the extraction process: volume of ionic liquid, volume of dispersant solvent, ionic strength, and pH. At the optimum working conditions, the average recoveries were 77.5 and 89.7%, the limits of detection were 0.06 and 0.09 μg mL-1 and the inter-day reproducibilities were 6.25 and 5.77% for benznidazole and nifurtimox, respectively. The proposed methodology can be considered sensitive, simple, robust, accurate, and green.
Acceso AbiertoA Molecular Imprinted Polymer as a Flow-Through Optical Sensor for Oxazepam(2018) Machicote, Roberta G.; Castillo, Marcela A.; Pacheco, María Emilia; Bruzzone, LilianaA flow-through optosensing system for oxazepam recognition with fluorescence detection was performed by means of a molecular imprinted polymer based on its acid hydrolysis product, 2-amino-5-chlorobenzophenone. )e synthesis was conducted via a noncovalent imprinting methodology, using methacrylic acid as a functional monomer and ethylene glycol dimethacrylate as a cross-linking agent. Hydrolysis (types and concentration of acids), polymer retention capacity, binding properties, and elution (selectivity and reversibility) conditions were optimized. )e selected molecular imprinted polymer had a molar ratio composition of 1 : 6 : 45 (template : functional monomer : cross-linker). )e proposed method was applied to the determination of oxazepam in a pharmaceutical formulation. External standard calibration, standard additions calibration, and Youden’s calibration were carried out in order to evaluate constant and proportional errors due to the matrix. )e developed metabolite-based recognition system for benzodiazepines is an innovative procedure that could be followed in routine and quality control assays.