Development and Validation of a Spectrophotometric Method for the Determination of Tramadol in Human Urine Using Liquid-Liquid Extraction and Ion Pair Formation

Tramadol is a widely used analgesic and one of the most common drug abuses in Egypt and Middle East. A simple, sensitive and rapid method for the analysis of tramadol in human urine was developed and validated. The analyte was isolated from basified urine using a single liquid–liquid extraction then analyzed by spectrophotometry after ion-pair formation. The calibration curves were linear in the range of 10 -50 μg/mL , the limit of quantitation and the limit of detection were calculated. The method was also valid to determine tramadol at higher concentrations (250 μg/mL) after dilution.The resulting method demonstrated intra and inter-day precision within 6.3 and 9.5%, respectively, and accuracy within ± 9.9 and ± 3.8%, respectively.There were no interferences from common analgesic, caffeine and nicotine.