CHAPTER 2 

 SAMPLING METHODS 



Introduction 



This chapter is an overview of methods of sampling and sample introduction. 

 It will introduce the rationale for the sampling criteria and illustratively examine the 

 various methods of sampling for the identification of volatile emanations from the 

 skin. 



Sampling Considerations 



Ideally, the end result of this work would be to achieve a sampling method 

 which maintains the integrity of the sample. Little chemical modification of the skin 

 emanations is desired such that detection of volatiles is as comparable as possible to 

 that of the mosquito sensilla. The mosquito chemosensilla show response to 

 airborne components which specifically cause activation. 



The components on the skin which are attractive to mosquitoes can be 

 transferred to glass via handling the glass object. Glass petri dishes handled by 

 humans are attractive in olfactometer experiments and indeed retain their attraction 

 for up to 6 hours [67]. Furthermore, differences in attraction between human 

 subjects are reflected in the attraction of the petri dishes handled by these subjects. 



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