Development 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

PADRÓ, JM; PELLEGRINO VIDAL, R; R. ECHEVERRÍA; A CALIFANO; M. RETA

JOURNAL OF SEPARATION SCIENCE

WILEY-V C H VERLAG GMBH

Lugar: Weinheim; Año: 2015 vol. 38 p. 1591 - 1600

1615-9306

Chagas disease, an infection caused by the protozoan parasite Trypanosoma cruzi, constitutes a major public health problem in Latin America. The two drugs currently available for the medical treatment are nifurtimox and benznidazole. Initial infections with Trypanosoma cruzi take place mostly in children, by a vector or by congenital transmission. As vector control improves, congenital transmission is rapidly becoming the main route of infection, highlighting the importance of the diagnosis of maternal infection. 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. 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 a simple and efficient method to quantify benznidazole and nifurtimox in human breast milk, with a simple sample pre-treatment followed by an ionic liquid based dispersive liquid?liquid microextraction combined with liquid chromatography and UV detection. For this technique, the ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate, has been used as ?extraction solvent?. A factorial design, called 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. The pH and volume of ionic liquid were the most influential parameters affecting the extraction of benznidazole, while for nifurtimox, the volume of ionic liquid, the ionic strength and an interaction term (volume of ionic liquid x KCl concentration) were significant.  The figures of merit for the proposed methodology were obtained and real samples coming from infected patients were analysed. At the optimum working conditions, the average recoveries were 77.5 % and 89.7 %, the LOD 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 cheap, simple, robust, accurate, and the extraction solvent is more compatible with the environment than a typical organic solvent.