258 

 EI fragmentation pattern is consistent with the structure. However, due to similarity 

 between isomers, the exact structure can't be postulated with reasonable certainty. 

 Compounds fitting this category are noted by a (C) code. If the EI pattern is 

 consistent with a particular class, but the substitution identity is not known, a code 

 of (D) is used. A code of (E) is given when the CI analysis for the compound did 

 not yield information about the (r^)- A code of F listed in the table refers the 

 reader to the text following this explanation of codes for additional discussion about 

 specific compounds. The final code (G) denotes compounds previously identified in 

 the literature, which are listed in table 5-1. 



There are four points of interest to be addressed concerning the compounds 

 listed in this table. The first concerns the four octene isomers listed in the table and 

 denoted by the remark code (F). These are listed in this fashion because in one or 

 more analyses, there were in fact four peaks attributable to octene. This holds true 

 for all multiple listings of isomers of the same compound. Any uncertainty as to the 

 possible structure is treated by listing the best reverse fit structure from the library 

 and using the remark code (C) to denote that this compound may in fact be an 

 isomer of the compound listed. Substituted benzenes, for which two isomeric peaks 

 are often detected, will include the meta- isomer, and either the ortho- or para- 

 listed with a (C) code. This is due to the similarity in the fragmentation of two or 

 more of these isomers which cannot be distinguished by visual inspection or by 

 library search of the mass spectra. 



