Circulating choline and phosphocholine measurement by a hydrophilic interaction liquid chromatography-tandem mass spectrometry.

ABSTRACT

Background: Given the growing interest in studying the role of choline and phosphocholine in the development and progression of tumor pathology, in this study we describe the development and validation of a fast and robust method for the simultaneous analysis of choline and phosphocholine in human plasma. Methods: Choline and phosphocholine quantification in human plasma was obtained using a hydrophilic interaction liquid chromatography-tandem mass spectrometry technique. Assay performance parameters were evaluated using EMA guidelines. Results: Calibration curve ranged from 0.60 to 38.40 µmol/L (R2 = 0.999) and 0.08-5.43 µmol/L (R2 = 0.998) for choline and phosphocholine, respectively. The Limit Of Detection of the method was 0.06 µmol/L for choline and 0.04 µmol/L for phosphocholine. The coefficient of variation range for intra-assay precision is 2.2-4.1 % (choline) and 3.2-15 % (phosphocholine), and the inter-assay precision range is < 1-6.5 % (choline) and 6.2-20 % (phosphocholine). The accuracy of the method was below the ±20 % benchmarks at all the metabolites concentration levels. In-house plasma pool of apparently healthy adults was tested, and a mean concentration of 15.97 µmol/L for Choline and 0.34 µmol/L for Phosphocholine was quantified. Conclusions: The developed method shows good reliability in quantifying Choline and Phosphocholine in human plasma for clinical purposes.