title: Evaluation of different scan methods for the urinary detection of corticosteroid metabolites by liquid chromatography tandem mass spectrometry.
abstract: Different approaches for the non-target detection of corticosteroids in urine have been evaluated. As a result of previous studies about the ionization (positive/negative) and fragmentation of corticosteroids, several methods based on both precursor ion (PI) and neutral loss (NL) scans are proposed. The applicability of these methods was checked by the injection of a standard solution containing 19 model compounds. Five of the studied methods (NL of 76 Da; PI of 77, 91 and 105; PI of 237; PI of 121, 147 and 171; and NL of 38 Da) exhibited satisfactory results at the concentration level checked (corresponding to 20 ng/ml in sample). Some other methods in negative ionization mode such as the NL of 104 Da were found to lack sufficient sensitivity. Some of the applied methods were found to be specific for a concrete structure (NL of 38 Da for fluorine containing corticosteroids) while others showed a wide range applicability (PI of 77, 91 and 105 showed response in all model compounds). Interference by endogenous compounds was also tested by the analysis of negative urines and urines spiked with different corticosteroids. The suitability of these methods for the detection of corticosteroid metabolites was checked by the analysis of urine samples collected after the administration of methylprednisolone and triamcinolone. A combination of the reported methods seems to be the approach of choice in order to have a global overview about the excreted corticosteroid metabolites.
authors.affiliation: DoCoLab, UGent, Department of Clinical Chemistry, Microbiology and Immunology, Technologiepark 30, B-9052 Zwijnaarde, Belgium. oscar.pozomendoza@ugent.be
authors.forename: Oscar J
authors.initials: OJ
authors.lastname: Pozo
authors.forename: Rosa
authors.initials: R
authors.lastname: Ventura
authors.forename: Núria
authors.initials: N
authors.lastname: Monfort
authors.forename: Jordi
authors.initials: J
authors.lastname: Segura
authors.forename: Frans T
authors.initials: FT
authors.lastname: Delbeke
mesh_terms: D000305:Adrenal Cortex Hormones / Q000378:metabolism* / Q000652:urine*; D000328:Adult; D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D008297:Male; D008775:Methylprednisolone / Q000008:administration & dosage / Q000652:urine; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014221:Triamcinolone / Q000008:administration & dosage / Q000652:urine; D055815:Young Adult
chemical_list: D000305:Adrenal Cortex Hormones; D014221:Triamcinolone; D008775:Methylprednisolone