Journal of Chromatography B: Biomedical Sciences and Applications
Determination of dichloroacetate and its metabolites in human plasma by gas chromatography–mass spectrometry1
Introduction
Sodium dichloroacetate (DCA) is an investigational drug with a potentially broad clinical spectrum, including utility in the treatment of acquired and congenital forms of lactic acidosis [1]. DCA is also a product of water chlorination 2, 3, and is a metabolite of certain industrial chemicals 4, 5and drugs, such as chloral hydrate [6]and chloramphenicol [7]. Neurotoxic and hepatotoxic effects of DCA in animals have focused attention on its putative role as an environmental hazard to humans, despite its relatively wide therapeutic index when administered chronically or acutely to children and adults in doses of 12.5 to 50 mg/kg of body weight [1].
Considerable interest exists, therefore, in evaluating the kinetics, metabolism and toxicology of DCA in humans. Accordingly, several analytical techniques have been developed previously to quantitate DCA and its metabolites in biological fluids, with limited success. High-performance liquid chromatography (HPLC), using an ultraviolet-visible (UV–Vis) detection, is applicable only for rather high drug concentrations, because DCA has a low UV absorption [8]. Augmenting the sensitivity of HPLC with a radioactive flow detector can be achieved 9, 10, but is impractical for clinical investigations. When DCA concentrations were measured by gas chromatography (GC) using an electron capture detector (ECD), its metabolites glyoxylate, glycolate and oxalate could not be detected 11, 12, 13, 14. Given the selectivity and sensitivity of mass spectrometry (MS), GC–MS methods have been utilized to quantitate DCA, but not its metabolites 15, 16. In this study, we developed and validated a sensitive and selective GC–MS method that is applicable to the study of DCA pharmacokinetics and metabolism in humans. Plasma lactate was measured as a means of correlating the pharmacokinetics with the pharmacodynamics of DCA.
Section snippets
Materials
Chemicals used in this investigation were [13C1,2]DCA sodium salt (>99.5%, custom synthesized by Cambridge Isotope Laboratories, Inc., Andover, MA, USA), [12C]DCA sodium salt (>99.8%) and oxalic acid dimethyl ester (TCI America, Portland, OR, USA), MCA, glycolic acid, glyoxylic acid monohydrate, 85% (d,l)-lactic acid and methyl esters of DCA, MCA, oxalic acid, (R)-(+)-lactic acid, 4-chlorobutyric acid (CBA) and 12% boron trifluoride–methanol complex (Aldrich Chemical Company, Inc., Milwaukee,
Typical total ion chromatograms (TIC) and internal standard
Presented in Fig. 1 are the TIC of the authentic compounds spiked in water (panel A) and the TIC of a plasma sample of a healthy volunteer collected one hour after intravenous administration of 25 mg/kg DCA ([12C]DCA/[13C]DCA, 50%/50%) (panel B). After investigating a number of halogenated acids, CBA, which did not interfere with analysis of other compounds, was chosen as the internal standard. The concentrations of DCA, [13C]DCA, MCA, glyoxylate, oxalate, lactate and CBA were 124.17, 84.97,
Conclusions
A GC–MS method was successfully developed and validated for simultaneous determination of lactate, DCA and its metabolites MCA, glyoxylate and oxalate in human plasma. Its accuracy and precision are comparable to those other HPLC and GC assays, while its sensitivity and selectivity are superior. In addition, derivatization of samples by our technique is simpler than silylation of organic acids [28], and it can be carried out in an aqueous environment, resulting in a high percentage yield
Acknowledgements
This study was supported by NIH grants R01ES07355, P42ES07375 and RR00082.
References (28)
Metabolism
(1989)- et al.
Toxicol. Appl. Pharmacol.
(1989) - et al.
Fundam. Appl. Toxicol.
(1991) - et al.
Biochem. Biophys. Res. Commun.
(1996) - et al.
Biochem. Pharmacol.
(1979) - et al.
Metabolism
(1994) - et al.
J. Am. Coll. Cardiol.
(1994) - et al.
Biochem. Pharmacol.
(1984) - et al.
J. Chromatogr.
(1993) - et al.
J. Chromatogr.
(1990)
Metabolism
Endocrinol. Metab. Clin. North Am.
Carcinogenesis
Drug Metab. Dispos.
Cited by (32)
Development of HPLC method for estimation of glyoxylic acid after pre-column fluorescence derivatization approach based on thiazine derivative formation: A new application in healthy and cardiovascular patients’ sera
2020, Journal of Chromatography B: Analytical Technologies in the Biomedical and Life SciencesCitation Excerpt :Several analytical methods were reported for determination of GA in different matrices including high performance liquid chromatography (HPLC) [8–17], gas chromatography (GC) [12,18,19], thin layer chromatography (TLC) [20], electrophoresis [21], voltammetry [22], polarography [20] and electrochemiluminescence [23]. However, most of these methods have several drawbacks either low sensitivity [9–11,13,14,16,20,23], utility of expensive and sophisticated equipment that are not available in most laboratories [12,18,19] or long analysis time [11,15–17]. Till now, few HPLC with fluorescence detection were reported [8,15,17], two of them were performed in our laboratory based on Petasis reaction [15,17], where GA reacted with a fluorescence labeling reagent: 1-pyreneboronic acid.
Derivatization method for the quantification of lactic acid in cell culture media via gas chromatography and applications in the study of cell glycometabolism
2018, Journal of Chromatography B: Analytical Technologies in the Biomedical and Life SciencesCitation Excerpt :Therefore, we determined that this method could be used to quantify lactic acid in cell culture media in a sensitive and reproducible manner. Different methods have been established to quantify lactic acid in biological samples (blood, urine, culture media) [19–23,32–34], however, our method featured significant advantages (Table 2). The derivatization reaction could be completed within 1 min and the entire reaction time was shorter than the reaction time in other methods.
A novel dual labeling approach enables converting fluorescence labeling reagents into fluorogenic ones via introduction of purification tags. Application to determination of glyoxylic acid in serum
2018, TalantaCitation Excerpt :Hence, it is obvious that the determination of glyoxylic acid in biological fluids is of great importance. The reported analytical methods for determination of glyoxylic acid in biological and environmental samples include HPLC-UV detection [14–16], HPLC-fluorescence detection (HPLC–FL) [5,17,18] and GC-flame ionization and mass spectrometric detection [19–21]. Though, these HPLC methods have some weaknesses including poor sensitivity and selectivity (Table S1, supplementary file).
A Mechanism-Based Pharmacokinetic Enzyme Turnover Model for Dichloroacetic Acid Autoinhibition in Rats
2017, Journal of Pharmaceutical SciencesLong-term safety of dichloroacetate in congenital lactic acidosis
2013, Molecular Genetics and MetabolismIn matrix derivatization of trichloroethylene metabolites in human plasma with methyl chloroformate and their determination by solid-phase microextraction-gas chromatography-electron capture detector
2013, Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences
- 1
Presented in part at the Pittsburgh Conference at Atlanta, USA, March, 1997.