257 

 originate naturally from the body, or are due to deposition on the skin from an 

 external source. There are approximately 40 component peaks found present in each 

 sample for which the identity could not be determined. These are included in this 

 table. 



The remark codes used for this table appear at the end of the table. Absence 

 of remark codes A-E indicates that this compound was identified with a relatively 

 high purity (greater than approximately 800 of 1000 maximum possible score) in 

 some cases. The purity value is generated by the library search program and reflects 

 a weighted average of the forward fit and reverse fit values. The forward fit value 

 is decreased when the sample mass spectrum contains additional masses not found 

 in the reference library mass spectrum. The reverse fit value is decreased when the 

 sample mass spectrum does not contain masses found in the reference library mass 

 spectrum. If the compound had a lower purity, but was confirmed in numerous 

 samples as well as a high reverse fit value, then the compound is reasonably certain 

 to be that which is listed. In most complex analyses, additional masses will be 

 present from background which will reduce the forward fit value but not affect the 

 reverse fit as greatly. 



A remark code of (A) denotes those compounds for which the identity is 

 questionnable; these compounds may even belong to a different class. If the 

 molecular weight is known, but the structure given is still questionnable, the 

 compound will be denoted with a (B) code. In some cases the r^ is known and the 



