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

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.

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.

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.

The developed method shows good reliability in quantifying Choline and Phosphocholine in human plasma for clinical purposes.