Determination of Tramadol in Urine using LC-MS/MS

Introduction: Analysis of Tramadol and N-desmethyl-tramadol in Human Urine

Tramadol is a weak µ-opioid receptor agonist and inhibitor of serotonin/noradrenalin re-uptake used for pain treatment and other indications such as treatment for restless leg syndrome and fibromyalgia. Tramadol is structurally similar to the natural opiate codeine. Tramadol is reported to have a lower risk of developing dependence than codeine. In addition, tramadol is extensively metabolized, where a total of 24 metabolites have been identified. This application presents an LC-MS/MS method for the analysis of tramadol in urine using reversed-phase LC-MS/MS aided by isotope internal standards.

The experimental conditions for Tramadol and N-desmethyl-tramadol analysis in urine using reversed-phase LC-MS/MS is given in Table 1, LC gradient conditions in Table 2, and performance data in Table 3.

Table 1. LC-MS/MS experimental conditions for Tramadol and N-desmethyl-tramadol analysis

Table 2. LC gradient conditions

Chromatograms for Tramadol and N-desmethyl-tramadol, and corresponding internal standards, are shown in Figure 2.

Table 3. LC and MS/MS performance data for Tramadol and N-desmethyl-tramadol

Conclusions

Human patient samples were analyzed along with standards and control samples. The linear range was found to be 25-1500 ng/mL.