Determination of gemfibrozil in pharmaceutical and urine samples by square-wave adsorptive stripping voltammetry using a glassy carbon electrode modified with multi-walled carbon nanotubes within a dihexadecyl hydrogen phosphate film

► GC electrode was modified with multi-walled carbon nanotubes. ► Square-wave adsorptive stripping voltammetric method was used for GEM determination. ► The analytical method was applied in pharmaceutical and urine samples. ► The results obtained were similar to those obtained using a HPLC method.