Determination of 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexanedionein plasma by direct injection into a coupled column liquid chromatographicsystem
M. Bielenstein et al., Determination of 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexanedionein plasma by direct injection into a coupled column liquid chromatographicsystem, J CHROMAT B, 730(2), 1999, pp. 177-182
The chemical substance 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexane
dione (NTBC) is in clinical use for the treatment of hereditary tyrosinemia
type 1. In the present study, the plasma concentration of NTBC was determi
ned by a coupled column liquid chromatographic method. A 20-mu l volume of
plasma was diluted with phosphate buffer, pH 2, and injected into a small p
recolumn (BioTrapAcid C-18) with a mobile phase containing sulfuric acid. T
he precolumn was based on the restricted access principle, i.e., retention
of NTBC within the lipophilic pores, while polar and large endogenous compo
unds were eluted with the void volume. NTBC was transferred to the analytic
al column using a mobile phase with a high content of acetonitrile. The com
pound was monitored by UV detection at 278 nm. The standard curve was linea
r between 0.3 and 69 mu M, and the between-day precision (RSD) was 3% (n=6
days) at 13.8 mu M and 14% (n=6 days) at 0.3 mu M NTBC in plasma. The quant
itation Limit was approximately 0.3 mu M using 20 mu l of plasma. (C) 1999
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