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 was also examined. Increased attraction of mosquitoes occurred in all cases for the 

 sample containing acid relative to the unmodified sample. 



Skin emanations collected on three 2.9 mm glass beads were found to contain 

 a greater amount of sample than is present from the dissolution of 0.15 mL 

 perspiration in 1 mL methanol. Due to the absence of components in the aqueous 

 phase, it is suspected that lactic acid (and other attractants) preferentially reside in 

 the oily/waxy phase which emanates from the sebaceous glands. Decreased attraction 

 to mosquitoes has been observed in cases of heavy perspiration. If attractants 

 preferentially reside closer to the skin, below the evaporating aqueous phase, then 

 the reduced attraction which is observed can be explained by a masking effect from 

 heavy perspiration. 



Tandem mass spectrometry was employed in initial experiments of this 

 dissertation project to compensate for short-column chromatography. The detailed 

 fragmentation studies of lactic acid also necessitated the use of MS/MS modes. A 

 daughter library of characteristic fragmentations was compiled and used to rapidly 

 assess the compound classes present. The results from the rapid screening yielded 

 a conservative estimate number of compound classes as well as number of 

 components present within each class (or similar classes). 



Over 350 GC peaks are observed in the work of Chapter 5. There are 310 

 components identified in the cryo-focused GC/MS analyses; approximately 20 of 

 these have been attributed to background. Human subjects observed throughout this 



