ONLINE HPLC TANDEM MASS-SPECTROMETRY ANALYSIS OF CONTAMINANTS OF L-TRYPTOPHAN ASSOCIATED WITH THE ONSET OF THE EOSINOPHILIA-MYALGIA-SYNDROME

The structural characterization of a number of contaminants of L-trypt ophan (Trp) associated with eosinophilia myalgia syndrome has been per formed for the first time by the powerful structural elucidation techn ique of tandem mass spectrometry coupled with on-line HPLC (LC-ESI-MS/ MS). The identity of the contaminants: peaks UV-5, 3-(phenylamino)alan ine, (PAA); E 1,1'-ethylidenebis(tryptophan); 200, 2-(3-indolylmethyl) -L-tryptophan; (all identified as case related) and peaks 1, 3-carboxy -1,2,3,4-tetrahydro-beta-carboline; 2, arboxy-1-methyl-1,2,3,4-tetrahy dro-beta-carboline; 100, 2-(2,3 dihydroxy-1-[3-indolyl]propyl)-L-trypt ophan; and 300 and 400, diastereomers of indolyl-methyl]-1,2,3,4-tetra hydro-beta-carboline, have been confirmed by this technique. By compar ison of tandem MS (MS/MS) data from these compounds with the MS/MS dat a of several other impurities, we have structurally characterized peak s CC, KK and OO, as well as two previously unreported components label ed as peak P18 and peak P31. Peak P18 was unresolved from the large Tr p peak and has been characterized as indole-3-ethylamine. Peak P31 was previously unresolved from peak 200, a case related compound and ther efore its structure is of extreme importance. This compound has been t entatively identified as 2-(3-indolyl)-L-tryptophan. (C) 1997 Elsevier Science Ireland Ltd.