title: Ultrasound-assisted dispersive liquid-liquid microextraction followed by GC-MS/MS analysis for the determination of valproic acid in urine samples.
abstract: BACKGROUND
  Valproic acid (VPA) is an anticonvulsant drug used for the treatment of epilepsy and bipolar disorder. A method based on simultaneous derivatization and dispersive liquid-liquid microextraction followed by GC-MS/MS analysis has been developed for the determination of VPA in urine samples.
  
  
  RESULTS
  This optimized and validated method shows good linearity with R(2) value of 0.999. LOD and LOQ of VPA was found to be 0.4 ng ml(-1) and 1.4 ng ml(-1), respectively. Recovery of VPA was found to be in the range of 80 to 92%.
  
  
  CONCLUSIONS
  The developed method can find its wide applicability for the routine analysis of VPA in toxicological and clinical laboratories.
authors.affiliation: Analytical Chemistry Laboratory, Regulatory Toxicology Group, CSIR-Indian Institute of Toxicology Research, MG Marg, Lucknow 226001, India.|Present address: Central Forensic Science Laboratory, Directorate of Forensic Science Services, Ministry of Home Affairs, Govt of India, House no. 16, Lachit Bhorpukhan Path, Tetalia, Gotanagar, Guwahati (Assam) - 781033, India.
authors.forename: Rajeev
authors.initials: R
authors.lastname: Jain
authors.affiliation: Analytical Chemistry Laboratory, Regulatory Toxicology Group, CSIR-Indian Institute of Toxicology Research, MG Marg, Lucknow 226001, India.|Academy of Scientific & Innovative Research (AcSIR), CSIR-IITR Campus, MG Marg, Lucknow 226001, India.
authors.forename: Manoj Kumar
authors.initials: MK
authors.lastname: Gupta
authors.affiliation: Analytical Chemistry Laboratory, Regulatory Toxicology Group, CSIR-Indian Institute of Toxicology Research, MG Marg, Lucknow 226001, India.|Academy of Scientific & Innovative Research (AcSIR), CSIR-IITR Campus, MG Marg, Lucknow 226001, India.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Chauhan
authors.affiliation: Analytical Chemistry Laboratory, Regulatory Toxicology Group, CSIR-Indian Institute of Toxicology Research, MG Marg, Lucknow 226001, India.|Department of Applied Chemistry, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raibareli Road, Lucknow, 226025, India.
authors.forename: Vivek
authors.initials: V
authors.lastname: Pandey
authors.affiliation: Analytical Chemistry Laboratory, Regulatory Toxicology Group, CSIR-Indian Institute of Toxicology Research, MG Marg, Lucknow 226001, India.|Academy of Scientific & Innovative Research (AcSIR), CSIR-IITR Campus, MG Marg, Lucknow 226001, India.|Pesticide Toxicology Laboratory, Regulatory Toxicology Group, CSIR-Indian Institute of Toxicology Research, MG Marg, Lucknow 226001, India.
authors.forename: Mohana Krishna
authors.initials: MK
authors.lastname: Reddy Mudiam
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D059627:Liquid Phase Microextraction; D009994:Osmolar Concentration; D012997:Solvents / Q000737:chemistry; D013010:Sonication; D016482:Urinalysis / Q000379:methods*; D014635:Valproic Acid / Q000302:isolation & purification / Q000652:urine*
chemical_list: D012997:Solvents; D014635:Valproic Acid