RESUMO
OBJECTIVE: To optimize and validate a specific, sensitive and fast liquid Chromatography coupled to triple quadrupole Mass Spectrometric (LC-MS / MS) technique for accurate detection of serum α-tocopherol (Vitamin E) levels. STUDY DESIGN: An experimental based study. PLACE AND DURATION OF STUDY: The Clinical and Forensic Toxicology section of Chughtai Lab, Jail Road Lahore, from April to September 2022. METHODOLOGY: Methanol was used to deproteinize serum samples. The chromatographic separation was achieved using an Agilent Infinity-Lab Poroshell 120EC-C18 column, Agilent 6470 LC-MS/MS (equipped with an Electron Spray Ionization source) in gradient elution mode using 0.1% LCMS grade formic acid in water and LCMS-grade methanol as mobile phases. Hexa-deuterated α-tocopherol was employed as internal standard to minimise matrix interferences. RESULTS: The retention time of α-tocopherol was 3.0 ± 0.1 minutes. The linear concentrations obtained were ranged from 0.05-2 mg/dL with ≥0.985% coefficient of linearity. Detection and lower quantification limits determined were 0.025mg/dL and 0.05mg/dL, respectively. Recovery ranged from 96.5 to 99.8% and ionization suppression was -15.2% and -15.9% at high and low concentrations of α-tocopherol in serum. Intra-day and inter-day coefficient variation values were 4.2-4.9% and 5.0-5.9%, respectively. CONCLUSION: An efficient and reliable tandem mass spectrometric technique for vitamin E analysis in serum was optimized, validated, and applied to 80 patient samples. This method has usefulness in clinical application for the accurate determination of vitamin E without potential matrix interferences. KEY WORDS: Vitamin E, LC-MS/MS, Tocopherol, Internal standard, Validation.
