Development of a Dispersive Liquid?Ionic Liquid Microextraction Method for the Determination of Nifurtimox and Benznidazole in Human Breast Milk. Optimization using a Central Composite Design

JUAN M. PADRÓ; ROCÍO B. PELLEGRINO VIDAL; LEIDY BIBIANA AGUDELO MESA; ALICIA CALIFANO; MARÍA E. MARSON; GUIDO MASTRANTONIO; MARIO RETA

New Orleans

Simposio; International Symposium of High Performance Liquid Phase Separations and Related Techniques; 2014

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 treatment, nifurtimox (NFX) and benznidazole (BNZ). Initial infections with T. cruzi take place mostly in children, by vector or 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 BNZ and NFX in human breast milk, with a simple pre-treatment followed by a ionic liquid based dispersive liquid?liquid microextraction (IL-DLLME), previous to an HPLC/UV analysis. For the IL-DLLME technique, the ionic liquid (IL), [C8C1im][PF6], has been used as ?extraction solvent? which was synthesized in our laboratory [1] and methanol as ?disperser solvent?. According to a previous work [2], four significant variables were selected to define the experimental field: volume of ionic liquid (VIL), volume of disperser solvent (VMeOH), KCl concentration (CKCl) and pH. A central composite design (CCD) was used and mathematical models able to describe the system were obtained, thus allowing finding the optimal conditions for the analysis. The pH and VIL significantly affected the extraction response of BNZ, while for NFX, VIL, CKCl and the interaction term ?VIL x CKCl? were significant. At the optimum working conditions, the predicted recoveries were 78.0 % and 91.6 % for BNZ and NFX, respectively. The reproducibility (inter-day) were 6.25 % and 5.77 % for BNZ and NFX, respectively. Real samples were analysed and figures of merit were obtained. The methodology is simple, robust, accurate and economical. [1] Padró, J. M. et al., Anal. Bioanal. Chem. 399 (2011) 2807?2820. [2] Padró, J. M. et al., Talanta 107(2013) 95?102.