RESUMEN

A porous and hydrophilic sorbent material was used in an extraction system, assisted by electric fields, for the extraction of cocaine in saliva and subsequent determination by ultra-high-performance liquid chromatography associated with sequential triple quadrupole mass spectrometry (UHPLC-MS/MS). The cellulose-based material was characterized by scanning electron microscopy, infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction. The time and voltage variables applied in the extraction process were investigated through a Doehlert experimental design, and with the best conditions found (35min and 300 V) some validation parameters were evaluated. The established working range was 1-100 µg L-1 (R2 > 0.99), and the detection and quantification limits determined were 0.3 and 0.8 µg L-1, respectively. Recoveries from 80 to 115% and coefficient of variation ≤15 and 16% for intra-day and inter-day assays, respectively, were obtained for sample concentrations of LOQ, 5, 25, and 75 µg L-1, indicating satisfactory accuracy and precision for the proposed method. In addition, the method presented no matrix effect, and the extraction efficiency was between 56 and 70%. The results showed that the material used has adequate physicochemical characteristics and can be applied as a sorbent and electrolyte support in multiphase extractions using electric fields.

Asunto(s)

Celulosa/química , Cromatografía Líquida de Alta Presión/métodos , Cocaína/análisis , Cocaína/aislamiento & purificación , Saliva/metabolismo , Extracción en Fase Sólida/métodos , Espectrometría de Masas en Tándem/métodos , Fenómenos Electromagnéticos , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Saliva/química , Saliva Artificial/química , Saliva Artificial/metabolismo , Extracción en Fase Sólida/instrumentación