Determination of Choline, Betaine, and Dimethylglycine in Plasma by a High-Throughput Method Based on Normal-Phase Chromatography–Tandem Mass Spectrometry

Abstract

Background:The quaternary ammonium compounds, choline and betaine, and dimethylglycine (DMG) reside along a metabolic pathway linked to the synthesis of neurotransmitters and membrane phospholipids and to homocysteine remethylation and, therefore, folate status. Lack of a convenient, high-throughput method for the determination of these compounds has prevented population-based studies of their possible associations with lifestyle, nutrition, and chronic diseases. Methods: Serum or plasma samples were deproteinized by mixing with three volumes of acetonitrile that contained d 9 -choline and d 9 -betaine as internal standards. We used a normal-phase silica column for the separation of choline (retention time, 2.8 min), betaine (1.3 min), DMG (1.15 min), and internal standards, which were detected as positive ions by tandem mass spectroscopy in the multiple-reaction monitoring mode, using the molecular transitions m/z 104360 (choline), m/z 113369 (d 9 -choline), m/z 118359 (betaine), m/z 127368 (d 9 -betaine), and m/z 104358 (DMG). Results: For all three metabolites, the assay was linear in the range 0.4 -400 mol/L, and the lower limit of the detection (signal-to-noise ratio ‫؍‬ 5) was <0.3 mol/L. The within-and between-day imprecision (CVs) was 2.1-7.2% and 3.5-8.8%, respectively. The analytical recovery was 87-105%. The fasting plasma concentrations (median, 25th-75th percentiles) were 8.0 (7.0 -9.3) mol/L for choline, 31.7 (27.0 -41.1) mol/L for betaine, and 1.66 (1.30 -2.02) mol/L for DMG in 60 healthy blood donors. In individuals who had eaten a light breakfast, plasma concentrations of all three metabolites

Measurement of marine osmolytes in mammalian serum by liquid chromatography–tandem mass spectrometry

“…To our knowledge, this is the first study to measure homarine and AsB using LC-MS/MS and the first to use D 4 -homarine and 13 C 2 -arsenobetaine as internal standards. Previously, Holm and coworkers [20] measured choline, betaine, and N,N-dimethylglycine (DMG) by MS/ MS after separation on a normal-phase silica column. We observed sharper peaks with the Cogent Diamond Hydride column than with an unmodified silica column of similar dimensions.…”

“…Bovine serum or seal plasma (50 ll) was added to 500 ll of extraction solvent, which consisted of 90% acetonitrile and 10% [20].…”

“…In this article, we describe a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous measurement of glycine betaine, TMAO, AsB, DMSP, and homarine in serum based on the method of Holm and coworkers [20]. Betaine, TMAO, and DMSP have been measured previously using LC-MS/MS [21][22][23].…”

One-Carbon Metabolism and Prostate Cancer Risk: Prospective Investigation of Seven Circulating B Vitamins and Metabolites

“…Concentrations of methionine, cysteine, and MMA were determined with the use of an isotope dilution gas chromatography-mass spectrometry method (17). Concentrations of methionine sulfoxide, choline, and betaine were determined by liquid chromatography-tandem mass spectroscopy (18). Vitamins B6 and B2 were also determined by liquid chromatographytandem mass spectroscopy (19).…”

Biomarkers Related to One-Carbon Metabolism as Potential Risk Factors for Distal Colorectal Adenomas

“…Serum concentrations of folate and vitamin B12 (cobalamin) were measured by microbiological assays (30,31), whereas methionine, choline, betaine, vitamin B2 species [riboflavin and flavin-mononucleotide (FMN)], and vitamin B6 species [pyridoxal 5 0 -phosphate (PLP), pyridoxal (PL), and 4-pyridoxic acid (PA)] were measured in plasma using liquid chromatography-tandem mass spectrometry (32,33). Samples were analyzed in batches of 86 and quality control included six calibration samples, two Figure 1.…”