A high selective and sensitive method for the detection of six psychotropic drugs in human urine by high performance liquid chromatography combined with resonance Rayleigh scattering spectra

Abstract

A highly selective and sensitive method of high performance liquid chromatography combined with resonance Rayleigh scattering spectra was developed for the detection of six psychotropic drugs, including Doxepin, Promethazine, Imipramine, Amitriptyline, Chlorpromazine and Clomipramine. This method was based on the weak intensity of the RRS of six drugs and its significant enhancement after combined with Erythrosine (Ery) in a pH 4.0–4.7 BR buffer solution. The linear range was between 0.05 and 20 μg mL⁻¹ with correlation coefficients (r) all above 0.9916. The limits of detection (S/N = 3) were in the range of 0.42 and 21.05 ng mL⁻¹. Because the RRS detection wavelength was special (the excitation wavelength was equal to the emission wavelength, λ_ex = λ_em = 295 nm) and some other substances in human urine do not form ion-association complex with the Ery, no interference from the matrix was observed. The proposed method was successfully applied to real human urine samples analysis.