Non-ionic surfactant concentration profiles in undamaged and damaged hair fibres determined by scanning ion beam nuclear reaction analysis

Nuclear Reaction Analysis (NRA) was used with a scanning MeV He-3 ion microbeam to determine the extent of permeation and segregation of a deuterated non-ionic surfactant (dC(12)E(5)) into virgin (undamaged) and alkalinic perm damaged hair fibres. 2-D concentration maps show an accumulation of deuterated surfactant in the cortex and medulla of both the virgin and damaged hair. By normalising to the matrix carbon, surfactant levels in the damaged hair were found to be three times higher than in the undamaged hair. This is the first reported direct spatial evidence of the penetration of surfactant into the centre of hair fibres. Furthermore it is the first application of NRA to this type of complex biological matrix. (C) 1997 Elsevier Science B.V