RESUMEN
Antibiotics include a wide range of compounds that in addition to having high solubility in water may be basic, acidic or neutral. Therefore, it is anticipated that no single method would be effective in simultaneously extracting all of these compounds. In recent times, microscale membrane extraction has evolved as a viable sample preparation alternative. The two major approaches are microscale supported liquid membrane extraction (micro-SLME) and microscale liquid-liquid membrane extraction (micro-LLME). An approach that includes micro-LLME as well as micro-SLME for acidic and basic compounds is presented for the extraction and concentration of diverse antibiotics in water. Enrichment factors as high as 2700 were achieved. Relative standard deviations ranged from 1.5% to 2.0%, and detection limits were as low as 92 ng/L.