Ein gaschromatographischer Nachweis von 6-Mercaptopurin im Serum von immunsupprimierten Transplantationspatienten

Abstract

The knowledge of serum levels of azathioprine or its metabolite 6-mercaptopurine is important for the monitoring of the immunosuppressive therapy after kidney transplantation, especially when kidney function is low. For this reason, the work of Bailey et al. was modified. 6-Mercaptopurine was extracted from the serum with a mixture of isopropanol-ethylacetate (1:1 v:v), derivatized with trimethylaniliniumhydroxyde and measured gaschromatographically. Sulfhydryl-protecting reagents were added to prevent loss of substance. Oxyethyltheophylline was used as the internal standard. The extraction and clean-up method recovered 80% of the 6-mercaptopurine present, the lower limit of sensitivity was 20 ng/ml, i.e., ten times lower than that of Bailey et al. The method could be realized on eight patients treated with azathioprine, the half life of the drug was about 20-40 min within the first hour i.v. application.

Simultaneous determination of azathioprine and its metabolite 6-mercaptopurine in human plasma using solid phase extraction-evaporation and liquid chromatography–positive electrospray tandem mass spectrometry

“…A number of analytical methods have been used to determine the azathioprine with 6-mercaptopurine. It involves mainly high performance liquid chromatography (Van Os et al, 1996, Fell andPlag, 1979), gas chromatography (Wypior et al, 1982) and very few liquid chromatography tandem mass spectrometry methods (Hofmann et al, 2012, Tibor et al, 2010 have been developed for the quantification in biological samples of plasma (El-Yazigi and Wahab,…”