Gas chromatographic-mass spectrometric detection of S-nitroso-cysteine and S-nitroso-glutathione.
A gas chromatographic-mass spectrometric (GC-MS) method is described for the quantitative determination of the S-nitroso compounds S-nitroso-cysteine (SNC) and S-nitroso-glutathione (GSNO) using their (15)N-labeled analogs, i.e., S(15)NC and GS(15)NO, as internal standards. The method is based on the specific conversion by HgCl(2) of the unlabeled and (15)N-labeled S-nitroso groups to nitrite and (15)N-nitrite, respectively, and their conversion to the pentafluorobenzyl derivatives. The method was applied to quantify GS(15)NO formed in the cytosol of washed human erythrocytes incubated with S(15)NC. Combination of high-performance liquid chromatography with GC-MS allowed specific and accurate quantification of SNC and GSNO externally added to human plasma ultrafiltrate (range 0-10 microM). Method accuracy and precision for SNC and GSNO were close to 100 and below 9%, respectively. As little as 0.1 nM GS(15)NO corresponding to 30 amol of (15)N-nitrite injected onto the column was precisely detected by the method.
Institute of Clinical Pharmacology, Hannover Medical School, Carl-Neuberg-Strasse 1, Hannover, D-30625, Germany. tsikas.dimitros@mh-hannover.de
D
D
Tsikas
J
J
Sandmann
S
S
Rossa
F M
FM
Gutzki
J C
JC
Frölich
D003545:Cysteine / Q000031:analogs & derivatives* / Q000097:blood; D003600:Cytosol / Q000737:chemistry / Q000378:metabolism; D004912:Erythrocytes / Q000737:chemistry / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D005978:Glutathione / Q000031:analogs & derivatives* / Q000097:blood; D006801:Humans; D007202:Indicators and Reagents; D009587:Nitrogen Isotopes; D009603:Nitroso Compounds / Q000097:blood*; D015203:Reproducibility of Results; D026422:S-Nitrosoglutathione; D026403:S-Nitrosothiols; D012680:Sensitivity and Specificity
D007202:Indicators and Reagents; D009587:Nitrogen Isotopes; D009603:Nitroso Compounds; D026403:S-Nitrosothiols; D026422:S-Nitrosoglutathione; C021315:S-nitrosocysteine; D005978:Glutathione; D003545:Cysteine