title: A new rapid micromethod for the assay of phenobarbital from dried blood spots by LC-tandem mass spectrometry.
abstract: Advantages of dried blood spot include low invasiveness, ease and low cost of sample collection, transport, and storage. We used tandem mass spectrometry (LC-MS/MS) to determine phenobarbital levels on dried blood spot specimens and compared this methodology to commercially available particle enhanced turbidimetric inhibition immunoassay (PETINIA) in plasma/serum samples. The calibration curve in matrix using D(5)-phenobarbital as internal standard was linear in the phenobarbital concentration range of 1-100 mg/L (correlation coefficient 0.9996). The coefficients of variation in blood spots ranged 2.29-6.71% and the accuracy ranged 96.54-103.87%. There were no significant differences between the concentrations measured using PETINA and LC-MS/MS (both had similar precision and accuracy) however, LC-MS/MS allows at least 1.5 times higher throughput of phenobarbital analysis and additionally offers ease of sample collection which is particularly important for newborns or small infants.
authors.affiliation: Mass Spectrometry and Pharmacology Laboratory, Pediatric Neurology Unit and Laboratories, Department of Neurosciences, A Meyer Children's Hospital, Florence, Italy.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: la Marca
authors.forename: Sabrina
authors.initials: S
authors.lastname: Malvagia
authors.forename: Luca
authors.initials: L
authors.lastname: Filippi
authors.forename: Francesca
authors.initials: F
authors.lastname: Luceri
authors.forename: Gloriano
authors.initials: G
authors.lastname: Moneti
authors.forename: Renzo
authors.initials: R
authors.lastname: Guerrini
mesh_terms: D000927:Anticonvulsants / Q000097:blood*; D001681:Biological Assay; D001774:Blood Chemical Analysis / Q000379:methods* / Q000706:statistics & numerical data; D001800:Blood Specimen Collection / Q000379:methods; D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007223:Infant; D007231:Infant, Newborn; D008875:Middle Aged; D009391:Nephelometry and Turbidimetry / Q000379:methods; D010634:Phenobarbital / Q000097:blood*; D010949:Plasma / Q000737:chemistry; D012680:Sensitivity and Specificity; D044967:Serum / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000927:Anticonvulsants; D010634:Phenobarbital