Thiodiglycolic acid-d4 (TDGA-d4) contains four deuterium atoms at the 2, 2, 2', and 2' positions. It is intended for use as an internal standard for the quantification of TDGA by GC- or LC-mass spectrometry. TDGA is a product of interaction of the cysteine component of glutathione with two-carbon units released during catabolism. It is found in concentrations below 20 mg/l in urine of healthy individuals and elevated following ingestion of certain drugs.1 Determination of TDGA concentration in urine has been used to characterize the metabolism of substances participating in methionine synthesis in order to identify imbalances leading to hyperhomocystinuria.2 Additionally, because TDGA is used as raw material in the polymer industry, its detection in human urine has served as a biomarker for exposure to carcinogenic vapors such as vinylchloride monomer produced during polymer manufacture.2
1.Navratil, T., Petr, M., Senholdova, Z., et al.Diagnostic significance of urinary thiodiglycolic acid as a possible tool for studying the role of vitamins B12 and folates in the metabolism of thiolic substancesPhysiol.Res.56(1)113-122(2007) 2.Cheng, Y.J., Huang, Y.F., and Ma, Y.C.Urinary thiodiglycolic acid levels for vinyl chloride monomer-exposed polyvinyl chloride workersJ.Occup.Environ.Med.43(11)934-938(2001)