Streamlined dispersive solid phase extraction for determination of amitriptyline, cocaine, and benzoylecgonine in urine

This study aimed to develop and validate an analytical method using dispersive solid phase extraction (d-SPE) with analysis by liquid chromatography coupled with diode array detector (HPLC-DAD). The developed technique showed detection limit of 100 ng/mL and 1300 ng/mL for cocaine, amitriptyline, and benzoylecgonine, respectively. The precision was less than 15% for 3 different analyte concentrations. The method shows no carryover, and stability was proven for cocaine and amitriptyline. When compared to other techniques, the current study presented a lower detection limit and used a smaller sample volume. The method was compared with the rapid immunoassay test on samples from patients with suspected intoxication, and was satisfactory, showing adequate sensitivity for the proposed application. The method using d-SPE/HPLC-DAD proved to be an appropriate technique to complement emergency toxicological analysis with a satisfactory total run time of 14 min for the detection of the 3 analytes of interest, which fits well into a fast-paced workflow.