title: Spectroscopic analysis of bosentan in biological samples after a liquid-liquid microextraction.
abstract: BACKGROUND
  Microextraction processes with UV-Vis measurement have been developed and validated for analysis of bosentan in biological samples.
  
  
  METHODS
  In this work, liquid-liquid microextraction procedures (DLLME & USAEME) were employed for cleanup, pre-concentration, and determination of bosentan in biological samples by UV-Vis spectroscopy at 270 nm. The method was validated and applied to the determination of bosentan in spiked serum, exhaled breath condensate and urine samples.
  
  
  RESULTS
  Various experimental factors including type of extraction and dispersive solvents and their volumes, pH, sonication time and centrifuging time were investigated. Under the optimum conditions, the method was linear in the range of 1.0-5.0 μg.mL(-1), with coefficient of determination (R(2)) of > 0.998. The limit of detection (LOD) was 0.07 mg.L(-1). Recovery of the target analyte in biological samples was 106.2%. The method could be easily applied for higher concentration of bosentan and needs more improvement for application in the pharmacokinetic investigations where more sensitive methods are required.
  
  
  CONCLUSIONS
  A simple, low cost, precise and accurate spectrophotometric analysis of bosentan in biological samples after liquid-liquid microextraction were developed and validated for routine analyses.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran.
authors.forename: Sanaz
authors.initials: S
authors.lastname: Sajedi-Amin
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran.
authors.forename: Karim
authors.initials: K
authors.lastname: Assadpour-Zeynali
authors.affiliation: Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Vahid
authors.initials: V
authors.lastname: Panahi-Azar
authors.affiliation: Department of Pharmacoeconomics and Pharmaceutical Administration, Faculty of Pharmacy, Pharmacoeconomics and Pharmaceutical Administration Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Abbas
authors.initials: A
authors.lastname: Kebriaeezadeh
authors.affiliation: Tuberculosis and Lung Disease Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Khoubnasabjafari
authors.affiliation: Tuberculosis and Lung Disease Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Khalil
authors.initials: K
authors.lastname: Ansarin
authors.affiliation: Department of Mechatronic Engineering, International Campus, University of Tabriz, Tabriz, Iran ; Kimia Idea Pardaz Azarbayjan (KIPA) Science Based Company, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Vahid
authors.initials: V
authors.lastname: Jouyban-Gharamaleki
authors.affiliation: Kimia Idea Pardaz Azarbayjan (KIPA) Science Based Company, Tabriz University of Medical Sciences, Tabriz, Iran ; Pharmaceutical Analysis Research Center and Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Abolghasem
authors.initials: A
authors.lastname: Jouyban
keywords: Exhaled breath condensate; Liquid–liquid microextraction; Serum; Urine samples