554 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS / • WATER •. //•""----'• "• .,•. • MANOMETER --.., I • • • VA•R SAMPLE • •RFORATED •'3• w.o. - - •-TEFLON LINED PLATE PURE ?LASS TUBE //-TEFLON BELLOWS AIiR •.....n /' IIt'l]•_•..,. VA PO R SAMPLE Ld ••,•COUNTERWEIGHT STRoeTC.• CAST SUPPORT • • . Figure 1. Arrangements for v•o• ch•c]• •mm humm•s kept at 40øC or higher. Teflon spaghetti tubing, wrapped with a Teflon- spaghetti insulated low-voltage electrically heated resistance wire, solves this di•culty. Several devices for accumulation and storage of samples are represented in Fig. 2. Collection of vapors from organic substances, which most odorants are, is conveniently accomplished by adsorption at surfaces of nonpolar large- surface-area organic polymers (8) (Fig. 2A). A Chromosorb 102©* is a suitable choice. Such polymers adsorb water vapor poorly, and if they are maintained above the dew point temperature of the emission during collec- tion (40øC is a safe level) they permit collection of odorants without col- lecting much water. Odorants are later desorbed by heating in an inert gas and transferred to analysis in a gas chromatograph (8). Odorants such as ammonia, hydrogen sulfide, and some highly volatile organic compounds nor- really existing as gases are not handled too well by this collection technique and require separate arrangements. Also, this collection technique is suitable only for analytical evaluations, since an equitable reconstitution of the sam- pit' to vapors for sensory evaluation is a complex undertaking. *Johns-Manville, Celite Division, New York, N.Y.

EVALUATION OF HUMAN BODY ODOR 555 A SAMPLE --- B SPRING TEFLON CLOTH POROUS ',.", ,", •• POROUS .... '•' '•' POLYMER STAINLESS fMER STEEL •-- 5cm --• SCREENS STAINLESS STEELTUBE 1,8 cm. O.D SUCTION SAMPLE-SUCTTEFLON•-• DISPOSABLE TYGON (FOOD GRADE)TUBING [ [ • BAG EFLON BAG I-•J 15 LITER PERISTALTIC PUMP c D Figure 2. Vapor sample collecting devices A simplified form of vapor collector is depicted by Fig. 2B. Polymers such as those used in Fig. 2A are placed, after thorough preparation by thermal purification in an inert gas stream, in Teflon cloth bags. The resulting pads are attached to the body and effectively collect odorous vapors. After expo- sure, the polymer powder is removed from the bag, and the absorbed sub- stances are desorbed and analyzed as is the case with the device shown in Fig. 2A. Again, a reconstitution of the sample for direct sensory evaluation is too complex to be practical. Sample collection for later sensory evaluation can be accomplished by the methods presently in use in atmospheric odor measurement (Fig. 2C & D). The sample is collected into a Teflon bag either by means of a peristaltic pump (Fig. 2C), or by pulling the sample into the bag, accomplished by pumping air out of the space between the bag and a rigid cylinder surround- ing the bag (Fig. 2D). In both techniques, the bag (and the peristaltic pump tubing in C) must be preconditioned to the sample before the actual sample is taken to satisfy the initial adsorption losses.