314 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS stick sample to its corresponding methyl ester (4). The methyl ricinoleate is then isolated by extraction with ether and determined on a glc column packed with Gas Chrom RZ (No. 03724)* coated with 4% Carbowax 20M--terephthalic aci.d (No. 08220).* The glc analysis involves the use of di(2-ethylhexyl) phthalate as the internal standard. Recoveries obtained by adding known amounts of castor oil to lipstick samples ranged from 94 to 100%. EXPERIMENTAL Apparatus and Reagents Gas Chromatograph The analytical instrument* equipped with hydrogen flame detector was operated under the following conditions: Temperatures: detector 300øC, injection port 300øC, oven 250-260øC helium flow 100-120 ml/ min. Glc Column The column (6 ft X 1/• in. o.d. copper) was packed with 4% Carbo- wax 20M-terephthalic acid, on Gas Chrom RZ coated as follows: 1.0 g of Carbowax 20M-terephthalic acid was dissolved in 200 ml of CHCla and added to 24.0 g of 80-100 mesh Gas Chrom RZ. Gas Chrom RZ can be coated in a 6-in. crystallizing dish or in a 1-1. round-bottom boiling flask having a -f 24/40 female joint. If a dish is used, it is evaporated to dry- ness on the steam bath, with gentle swirling. If a flask is used, it is at- tached to a rotary evaporator and solvent is removed under reduced pres- sure while the temperature of the water bath is carefully raised to 50øC. A vacuum oven may be used to remove traces of solvent from the dry ma- terial. The dried material was packed in the column at 35-1b pressure, using a vibrator.* The column was programmed from 100 to 260øC at 4øC/min and conditioned overnight at 260øC with a helium flow of 120 ml/min. Refiuxing Apparatus This consisted of a 100-ml round-bottom flask with water-cooled re- fluxing condenser and heating mantle. * Applied Science Labs., State College, Pa. t F g• M Model 700, Hewlett-Packard Co., 1501 Page Mill Rd., Pal, o Alto, Calif. 94304. * Column-pak, Chemical Research Services, Inc., 14 Industrial Road, Addiso,n, Ill. 60101. is convenient.

CHROMATOGRAPHY OF CASTOR OIL IN LIPSTICK 315 Methyl Ricinoleate* The compound may be prepared from castor oil USP or technical grades of methyl ricinoleate* by following the procedure described in transesterification of the Sample, using a 1-g sample and 3 times the amount of transesterification reagent and extraction solvents. The' transesterification was carried out in a 250-ml boiling flask and the ex- tractions were made in 250-ml separatory funnels. The ether-extractable residue was reserved for purification by adsorption chromatography. A small glass wool plug was tamped into the bottom of a 24 X • in. i.d. glass chromatograph tube and the tube was filled with about 100 ml of CHCla. A slurry was made of 40 g of silica gel with 100 ml of CHCla, and half the slurry was poured into the chromatograph tube. The col- umn was packed by applying 5-6 lb of air pressure to the tube. In this and subsequent steps the solvent should not be permitted to drain below the surface of the silica gel. The remainder of the slurry was then packed as before. The reserved ether e•ctract was dissolved in 40 ml of hot CHCla and the solution was transferred to the chromatographic column. The beaker was rinsed with two 20-ml portions of CHCI• and the rinsings were added to the chromatographic column after the initial solution drained into the silica gel. Elutio.n was continued with 120 ml of CHCla and 200 ml (9 -• 1) of CHCla-ethyl ether (anhydrous). The CHCla eluate was discarded and the CHCla-ethyl ether eluate was collected in 25-ml t•ortions in tared 50-ml beakers. The collected CHCla-ethy] ether eluates were evaporated on the steam bath under a jet of air and the residues were heated at 105øC in a drying oven for 5 min. The residues were then cooled and weighed. The four largest residues were combined and rechromatographed by the previously described procedure. Again, the four largest residues were combined and reserved as "methyl ricinoleate standard." Transesterification Mix Methanol-benzene-concentrated sulfuric acid (3 -k 1 -k 0.037) was prepared fresh every 2 or 3 days. * HE 1821, Analabs, Inc., North Haven, Corm. 06473. ? It may be necessary to "transesterify" technical grades of methyl ricinoleate because they often con,tain unreacted glyceri. des.