LC/MRM quantification of protein-bound chlorotyrosine and bromotyrosine in serum of patients infected by inflammatory bowel disease

摘要

We developed an analytical method to quantify protein-bound ClTyr and BrTyr simultaneously in biological samples at low femtomole levels. Mild digestion minimizes artifactual halogenation during the sample preparation. No obvious artifactual chlorination was observed. HPLC purification successfully cleans the ClTyr and BrTyr from the digestion mixture, which leads to clean LC/MRM chromatography. The quantification results of blinded human serum samples demonstrated that ClTyr is more closely correlated than BrTyr to IBD diseases.