TESTING DEODORANTS WITH CHLOROPHYLL AND DERIVATIVES 39 fresh and non-odorous samples are: (a) acetic acid, (b) caproic acid, (c) caprylic acid, and (d) burytic acid. The preceding citations of data for volatile bases and acids include only compounds in either category which have been identified in the author's laboratory in samples of stale or stored perspiration. It is not intended that these lists of either group of compounds be regarded as representative of all of the volatile bases and acids which might be end products of metabolic activities of micro-organisms growing and multi- plying on surfaces of skins of human subjects. The purpose of this introduction has been to summarize the principal chemical and biological reactions which take place among the chemi- cal and microbial constituents of perspiration on the cutaneous sur- face and result in the production of offensively odorous compounds. An understanding of these reactions is fundamental to an intelligent ap- preciation of the modes of action of topical deodorants. Furthermore, a clear comprehension of these fundamentals is an essential pre- requisite to the planning of experi- mental studies of deodorants and, also, to the interpretation of the experimental results. F, XPERIMENTAL STUDIES OF TOPICAL DEODORANTS This group includes all prepara- tions which are intended for topical applications to surface areas of the body in order to achieve direct in- hibitory or deodorizing actions upon either the sources of or the agents producing the odors. Some chloro- phyll derivatives are classified in this group. In experimental studies directed to appraisals of chlorophyll and of products derived from it, the first problem confronting the experimen- talist is the selection of an analytical procedure which may be adapted to determinations of either the pigment itself or of the derivatives alleged to be deodorants. Charts II and III have been pre- pared with the objective of illustrat- ing the basic principles of the analytical procedure in use in the author's laboratory. These charts present transmission curves for four preparations which are described below. l. Natural Chlorophyll. This is a sample of chlorophyll which had been prepared from spinach by extraction with acetone (16). The crude product contained 8 per cent of chlorophyll. It was purified (90 per cent) by repeated extrac- tions with immiscible, organic sol- vents. This method was a modi- fication of the technique originally utilized by Willstiitter and his collaborators (17). Chlorophyll"a" made up 69.4 per cent of the puri- fied product and 30.6 was in the form of chlorophyll "b." Its mag- nesium content was 2.39 per cent which is about 90 per cent of the theoretical. This natural chloro- phyll was insoluble in water but soluble in acetone and ethyl ether. 2. Water-Soluble Chlorophyllins

40 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS 0-8001 I I I I I o.,oot3 • 0'600 [/- i A - •i ø'5øøV i / i0'400[-- i • ! \ 4oo 45o 500 55o 8oo 85o w•w L[,0T.S m M•LUM•C•0,S Chart II.•Comp•ative transmission curves for natural chlorophyll and for sodium magnesium chlorophyllins prepared from the natural chlorophyll. • natural chlorophyll, - - - water-sol• hie chlorophyllins. 0.800 0.700 0,600 0.500 0.400 0.300 0.200 •100 o 4o0 Chart 450 500 550 600 650 700 WAVE LENGTHS IN MILLIMICRONS Ill.--Comparative transmission curves for a preparation of sodium-copper chlorophyllins and an acid-digest of chloro- phyll in alkaline solutions. • water-soluble chlorophyllins, - - - acid-digest of chlorophyll. "a" and "g." This product was prepared by alkaline saponification of a portion of the purified natural chlorophyll. The resulting prod- uct, in dry form, contained 1.68 per cent of magnesium but no copper. It was readily soluble in water but only sparingly soluble in either ethyl ether or acetone. 3. dcid-Digest of Natural Chloro- phyll. This derivative or mixture of derivatives was prepared by add- ing to a portion of the natural chlorophyll an equal weight of 2 M HC1 and, then, maintaining this mixture at 37øC. by heating in a water bath for two hours. At the end of this period the black-green precipitate was filtered off under pressure and then washed with water until the flitrate returned chlorine-free. Thereafter, the pre- cipitate was suspended in water- and stirred thoroughly during titra- tion with 0.01 N NaOH to pH = 7.00 as determined by a Beckman pH Meter. 'Finally, the suspended precipitate was filtered off under pressure, chlorides were removed by repeated washings with water and, finally, the precipitate was dried to constant weight. The preparation was insoluble in water and only sparingly soluble in acetone and ethyl ether. •. I4Zater-Soluble Sodium-Copper Chlorophyllins. Two samples of this preparation were made available for this and other investigations by the Rystan Company, Inc. The samples differed only in their states of purity. One sample was 93 per cent pure chlorophyllins and it con-