title: Simple method for the routine determination of betaine and N,N-dimethylglycine in blood and urine.
abstract: A simple and convenient method using commercially available derivatization reagents is described for the measurement of betaine and N,N-dimethylglycine (DMG) in blood and urine. Precolumn derivatization of plasma or urine is performed directly in acetonitrile without extraction with p-bromophenacyl bromide and crown ether as catalyst. The p-bromophenacyl ester derivatives are then separated by high-performance liquid chromatography, using an isocratic system of acetonitrile and water containing choline. Effluent was monitored at 254 nm. The limit of detection was 5 micromol/L for betaine and 2 micromol/L for DMG. Analytical recovery was >97% for both analytes. Total and within-day CVs were 2.0-4.4% and 0.9-2.2% for DMG. For betaine, the total and within-day CVs were 1.3-5.3% and 0.4-3.8%, respectively. The method is precise and cost-effective and has been used successfully to determine the concentrations of DMG and betaine in human plasma and urine.
authors.affiliation: Heinrich-Heine University, Children's Hospital, Metabolic Unit, Düsseldorf, Germany. Laryea@uni-duesseldorf.de
authors.forename: M D
authors.initials: MD
authors.lastname: Laryea
authors.forename: F
authors.initials: F
authors.lastname: Steinhagen
authors.forename: S
authors.initials: S
authors.lastname: Pawliczek
authors.forename: U
authors.initials: U
authors.lastname: Wendel
mesh_terms: D000328:Adult; D001622:Betaine / Q000097:blood* / Q000652:urine*; D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007223:Infant; D008875:Middle Aged; D012016:Reference Values; D012521:Sarcosine / Q000031:analogs & derivatives* / Q000097:blood / Q000652:urine; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet
chemical_list: D001622:Betaine; C025138:dimethylglycine; D012521:Sarcosine