A new rapid micromethod for the assay of phenobarbital from dried blood spots by LC‐tandem mass spectrometry

• Published in: Epilepsia (Copenhagen) Vol. 50; no. 12; pp. 2658 - 2662
• Main Authors: La Marca, Giancarlo, Malvagia, Sabrina, Filippi, Luca, Luceri, Francesca, Moneti, Gloriano, Guerrini, Renzo
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.12.2009; Wiley-Blackwell
• Subjects: Anticonvulsant; Anticonvulsants - blood; Anticonvulsants. Antiepileptics. Antiparkinson agents; Antiepileptic; Biological and medical sciences; Biological Assay; Blood Chemical Analysis - methods; Blood Chemical Analysis - statistics & numerical data; Blood Specimen Collection - methods; Calibration; Chromatography, High Pressure Liquid; Chromatography, Liquid - methods; Epilepsy; Headache. Facial pains. Syncopes. Epilepsia. Intracranial hypertension. Brain oedema. Cerebral palsy; Humans; Immunoassay - methods; Infant; Infant, Newborn; Liquid chromatography‐tandem mass spectrometry; Medical sciences; Middle Aged; Nephelometry and Turbidimetry - methods; Nervous system (semeiology, syndromes); Neurology; Neuropharmacology; Particle enhanced turbidimetric inhibition immunoassay; Pharmacology. Drug treatments; Phenobarbital; Phenobarbital - blood; Plasma - chemistry; Sensitivity and Specificity; Serum - chemistry; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry - methods; Nervous system diseases; Psychotropic; Epilepsy; Antiepileptic; Hypnotic; Liquid chromatography-tandem mass spectrometry; Anticonvulsant; Liquid chromatography; Cerebral disorder; Particle; Phenobarbital; Central nervous system disease; Sedative; Barbiturates; Particle enhanced turbidimetric inhibition immunoassay; Mass spectrometry
• ISSN: 0013-9580; 1528-1167
• DOI: 10.1111/j.1528-1167.2009.02204.x

Summary 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 D5‐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.