204 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Figure 5. Scanning electron micrograph of HPA. DEODORIZING EFFICACY OF HYBRID POWDERS Under the GC condition described in the Experimental section, isovaleric acid elutes at a retention time of 2.3 minutes and caproic acid at 3.7 minutes, as observed from the chromatogram of standard acid aqueous solution shown in Figure 6A. Both acids are Table I Texture Efficacies by the Direct Evaluation Method Sample -••luation A•B A)B A = B A(B A•B A: HPZ B: Fine-particle zinc oxide 17 2 0 0 1 A: HPA B: Fine-particle ACH 6 ! 1 1 2 0 Wilcoxon sign-rank test: HPZ ) fine-particle zinc oxide P = 0.000362. HPA ) fine-particle ACH P = 0.000923. Table II Coefficient of Kinetic Friction Measured Instrumentally Coefficient of Sample kinetic friction Nylon 12 0.39 Polyethylene powder 0.34 Zinc oxide 0.65 HPZ 0.34 ACH 0.50 HPA 0.36

HYBRID POWDERS FOR BODY MALODORS 205 iso-valeric acid caproic acid Q .... , .... I .... • ........ • .... I .... ' .... I .... • .... ! .... ' .... I .... '' 0 1 2 • 4 $ 6 '"• retention time (min) Figure 6. Headspace gas chromatograms of standard acid solution (A), standard acid solution + talc (B), and standard acid solution + fine-particle zinc oxide (C).