Abstract: A method for determining a narcotic in a mixture comprising at least one interferant. The method comprises: (a) determining a voltage at which, in absence of the interferant, a voltammetric signal of the narcotic can be detected; (b) contacting an electrode with the mixture comprising the at least one interferant and potentially comprising the narcotic; (c) applying a pretreatment potential to the electrode for a duration of at least 5 seconds, the pretreatment potential measuring between ?0.4 V and ?2 V versus Ag/AgCl; (d) measuring a voltammetric response of the mixture, the measurement comprising at least the determined voltage; and (e) determining whether the narcotic is present in the mixture by analyzing whether the voltammetric signal of the narcotic, resolved from a voltammetric signal of the interferant, can be detected in the measured voltammetric response.

Abstract: A computer-implemented method for interpreting an electrochemical response, comprises the steps of: (a) providing an electrochemical response that is baseline-corrected; (b) identifying in the electrochemical response one or more peaks that exceed a predetermined height threshold and a predetermined prominence threshold, each identified peak having a peak position; (c) providing a predetermined peak position range for each of a plurality of analytes; and (d) attributing one or more of the analytes to the peaks identified in step b, by, for each peak, associating the peak with an analyte when the peak position falls within the predetermined peak position range for the analyte.

Abstract: A method for determining a narcotic in a mixture comprising at least one interferant. The method comprises: (a) determining a voltage at which, in absence of the interferant, a voltammetric signal of the narcotic can be detected; (b) contacting an electrode with the mixture comprising the at least one interferant and potentially comprising the narcotic; (c) applying a pretreatment potential to the electrode for a duration of at least 5 seconds, the pretreatment potential measuring between ?0.4 V and ?2 V versus Ag/AgCl; (d) measuring a voltammetric response of the mixture, the measurement comprising at least the determined voltage; and (e) determining whether the narcotic is present in the mixture by analyzing whether the voltammetric signal of the narcotic, resolved from a voltammetric signal of the interferant, can be detected in the measured voltammetric response.