Fluoxetine and norfluoxetine analysis by direct injection of human plasma in a column switching liquid chromatographic system

• Published in: Journal of separation science Vol. 31; no. 1; pp. 78 - 85
• Main Authors: Santos-Neto, Alvaro J, Fernandes, Christian, Rodrigues, José C, Alves, Claudete, Lanças, Fernando M
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley-VCH Verlag 2008; WILEY-VCH Verlag; WILEY‐VCH Verlag; Wiley
• Subjects: Analysis; Biological and medical sciences; Chromatography, Liquid - instrumentation; Chromatography, Liquid - methods; Column switching; Direct injection; Fluoxetine; Fluoxetine - analogs & derivatives; Fluoxetine - blood; Fluoxetine - chemistry; General pharmacology; Humans; Medical sciences; Molecular Structure; Online sample preparation; Pharmacology. Drug treatments; Plasma - chemistry; Restricted access media; Solid phase extraction; Biological fluid; Chemical analysis; Column switching; On line; Metabolite; Psychotropic; HPLC chromatography; Reuptake inhibitor; Blood; Chemical enrichment; Blood plasma; Direct method; Sample preparation; Antidepressant agent; Quantitative analysis; Direct injection; Trace analysis; Human; Serotonin; Restricted access medium column; Restricted access media; Fluoxetine; Coupled method; Online sample preparation; Reversed phase chromatography; Ultraviolet detector; Neurotransmitter
• ISSN: 1615-9306; 1615-9314
• DOI: 10.1002/jssc.200700153

A column switching LC method is presented for the analysis of fluoxetine (FLU) and norfluoxetine (NFLU) by direct injection of human plasma using a lab-made restricted access media (RAM) column. A RAM-BSA-octadecyl silica (C-18) column (40 mmx4.6 mm, 10 μm) is evaluated in both backflush and foreflush elution modes and coupled with a C-18 lab-made (50 mmx4.6 mm, 3 μm) analytical column in order to perform online sample preparation. Direct injection of 100 μL of plasma samples is possible with the developed approach. In addition, reduction of sample handling is obtained when compared with traditional liquid-liquid extraction (LLE) and SPE. The total analysis time is around 20 min. A LOQ of 15 ng/mL is achieved in a concentration range of 15-500 ng/mL, allowing the therapeutic drug monitoring of clinical samples. The precision values achieved are lower than 15% for all the evaluated points with adequate recovery and accuracy. Furthermore, no matrix interferences are found in the analysis and the proposed method shows to be an adequate alternative for analysis of FLU in plasma.