title: Determination of phentermine, N-hydroxyphentermine and mephentermine in urine using dilute and shoot liquid chromatography-tandem mass spectrometry.
abstract: Nonmedical use of prescription stimulants such as phentermine (PT) has been regulated by law enforcement authorities due to its euphorigenic and relaxing effects. Due to high potential for its abuse, reliable analytical methods were required to detect and identify PT and its metabolite in biological samples. Thus a dilute and shoot liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed and validated for simultaneous determination of PT, N-hydroxyphentermine (NHOPT) and mephentermine (MPT) in urine. A 5μL aliquot of diluted urine was injected into the LC-MS/MS system. Chromatographic separation was performed by reversed-phase C18 column with gradient elution for all analytes within 5min. Identification and quantification were based on multiple reaction monitoring (MRM) detection. Linear least-squares regression with a 1/x(2) weighting factor was used to generate a calibration curve and the assay was linear from 50 to 15000ng/mL (PT and MPT) and 5 to 750ng/mL (NHOPT). The intra- and inter-day precisions were within 8.9% while the intra- and inter-day accuracies ranged from -6.2% to 11.2%. The limits of quantification were 3.5ng/mL (PT), 1.5ng/mL (NHOPT) and 1.0ng/mL (MPT). Method validation requirements for selectivity, dilution integrity, matrix effect and stability were satisfied. The applicability of the developed method was examined by analyzing urine samples from drug abusers.
authors.affiliation: Forensic Science Division II, Supreme Prosecutors' Office, Seoul 06590, Republic of Korea.
authors.forename: Yun Jeong
authors.initials: YJ
authors.lastname: Choi
authors.affiliation: Forensic Science Division II, Supreme Prosecutors' Office, Seoul 06590, Republic of Korea.
authors.forename: Arum
authors.initials: A
authors.lastname: Sim
authors.affiliation: Forensic Science Division II, Supreme Prosecutors' Office, Seoul 06590, Republic of Korea.
authors.forename: Min Kyung
authors.initials: MK
authors.lastname: Kim
authors.affiliation: Forensic Science Division II, Supreme Prosecutors' Office, Seoul 06590, Republic of Korea.
authors.forename: Sunglll
authors.initials: S
authors.lastname: Suh
authors.affiliation: Forensic Science Division II, Supreme Prosecutors' Office, Seoul 06590, Republic of Korea.
authors.forename: Moon Kyo
authors.initials: MK
authors.lastname: In
authors.affiliation: Office of Forensic Science Planning, Supreme Prosecutors' Office, Seoul 06590, Republic of Korea. Electronic address: paxus@spo.go.kr.
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Kim
mesh_terms: D000697:Central Nervous System Stimulants / Q000652:urine*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D008616:Mephentermine / Q000652:urine*; D010645:Phentermine / Q000031:analogs & derivatives* / Q000652:urine*; D015813:Substance Abuse Detection / Q000379:methods*; D013566:Sympathomimetics / Q000652:urine*; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D000697:Central Nervous System Stimulants; D013566:Sympathomimetics; C013568:N-hydroxyphentermine; D010645:Phentermine; D008616:Mephentermine
keywords: LC–MS/MS; Mephentermine; N-Hydroxyphentermine; Phentermine; Urine