title: Rapid determination of letrozole, citalopram and their metabolites by high performance liquid chromatography-fluorescence detection in urine: Method validation and application to real samples.
abstract: This work reports the validation of a high precision and accuracy method for the simultaneous determination of letrozole, citalopram and their metabolites in urine by high performance liquid chromatography with fluorescence detection. Dilution (urine:mobile phase, 1:2, v/v) was the only sample preparation step. The separation was carried out in a Kromasil C(18) (150mm×4.6mm) column, and the mobile phase was phosphate buffer 80mM (pH 3.0) and acetonitrile (65:35, v/v) at a flow rate of 1.0mL/min. The analytes were detected at 295nm after excitation at 230nm. Linearity was observed in the range of 1.0-1000ng/mL for letrozole and its metabolite and 2.5-1000ng/mL for citalopram and their metabolites, with limits of detection and quantification between 0.09-1.0 and 0.27-1.65ng/mL, respectively. The precisions were satisfactory with RSDs between 0.17 and 5.71%. The accuracy was studied by spiking three urines from healthy female volunteers, and the recoveries were from 85 to 103%. The method was applied to urine samples from women under treatment for breast cancer and depression diseases.
authors.affiliation: Department of Analytical Chemistry and Food Technology, University of Castilla-La Mancha, 13071 Ciudad Real, Spain. juana.rflores@uclm.es
authors.forename: J
authors.initials: J
authors.lastname: Rodríguez
authors.forename: G
authors.initials: G
authors.lastname: Castañeda
authors.forename: L
authors.initials: L
authors.lastname: Muñoz
mesh_terms: D018687:Antidepressive Agents, Second-Generation / Q000737:chemistry / Q000302:isolation & purification / Q000627:therapeutic use / Q000652:urine*; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification / Q000627:therapeutic use / Q000652:urine*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000652:urine; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D015283:Citalopram / Q000737:chemistry / Q000302:isolation & purification / Q000652:urine*; D003863:Depression / Q000188:drug therapy / Q000652:urine; D016903:Drug Monitoring; D005260:Female; D006801:Humans; D000077289:Letrozole; D057230:Limit of Detection; D008875:Middle Aged; D009570:Nitriles / Q000737:chemistry / Q000302:isolation & purification / Q000652:urine*; D015203:Reproducibility of Results; D013050:Spectrometry, Fluorescence / Q000379:methods*; D014230:Triazoles / Q000737:chemistry / Q000302:isolation & purification / Q000652:urine*
chemical_list: D018687:Antidepressive Agents, Second-Generation; D000970:Antineoplastic Agents; D009570:Nitriles; D014230:Triazoles; D015283:Citalopram; D000077289:Letrozole