Determination of Volatile Phenols in Cigarette Smoke C. H. RAYBURN, W. R . HARLAN,
AND
H. R . HIII\J.\IER
Research Department, The American Tobacco Co., Richmond 11, l u .
tightness is not essential, as slight evaporation improves the separations. Excessive evaporation gives hands which are too close together. Aft,er development. four bands can he identified by color and position as follows: (1) About 5 to 8 cm. above the starting line is a violet band, TFhich is the guaiacol derivative. (2) Ai broad rose I.)and, 1.5 to 20 cni. f l ~ m the start,ing line, is the phenol derivative. (3) Just above the rose hand is a narrower red band ,&ich is the 17r-creso] derivative, (4) Above the m-creso] band is a reddish-purple band containing the o-cresol derivative. The identity of these bands can be established with chromatographs of derivatives of known compounds, singly, in mixtures, and in mixtures with the derivatives of smoke. .4band appearing above the o-cresol derivative is apparently a mixture of several phenolic APPARATUS derivatives present in small amounts. .\utomaric. snokiiig macshine ( 1 ) . The paper sheets are cut lengthwise into strips, with each (‘ylintlrii~alglass jars. 20 cm. i n diameter arid 4 i cm. in height. derivative on a separate strip. The derivatives are eluted by dowimard development with 80% isopropyl alcohol in a cabinet coverrtl with glass plates. ( ‘hromat80gaphic~ cabinet, for descending paper chromatogr:ifor descending chromatography, allon-ing the solvent to drip from the end of the strip into a beaker. When elution is comph).. er. plrtth, the solvent is allowed to evaporate from the beakers. The i3ecknzh n D L- spect i~ophotonict residues are dissolved in a little 20% isopropyl -~ alcohol-sodium carbonate solution, the solutions are filtered through a small plug of cotton to remove Table I . Cbncentration of Phenols i n Cigarettes f r o m Four‘robaccos suspended matter and are made up to 25 ml. for a T y p e ~i Wt. of 10 Smoke Phenol, Guaiacol. n-Cresol, o-Cresol. guaiacol Or derivative, and to loo for the T0bacr.u (C‘igarettes, G. Volume. 1., Mg./L. XIg./L. XIg.!L, >le./L. uhenol derivat’ive. The absorbance of each solution is determined in a 1-cm. cell, using a Beckman DU Bright 11.12 3.99 0.508 0.070 0.073 0.085 spectrophotometer, a t 510 mp for guaiacol and t’he 0 370 0.052 0.061 8.72 2.56 B I I rle y 0.081 13.34 3.01 0.337 0.043 0.0411 0.069 Turki4i cresols and a t 490 m p for phenol. The values for ab8 . 59 0 4.-, 0 420 AIarylbrid 0 061 0. ofis 0.086 sorbance of each of these phenols are plotted against volume of diazo reagent used. The absorbances near the maximum for each curve are averaged in order to obtain the maximum value for that compound. SPECIAL REAGENTS -4 solution is prepared containing in 250 ml. 2.0 mg. of phenol Diazo Reagent. Dissolve 0.7 gram of p-nitroaniline in 9 ml. of and 0.30 mg. each of guaiacol, m-cresol, and o-cresol. Using coiicentiated hydrochloric acid and dilute to 100 ml. Cool 4 ml. amounts of diazo reagent varying from 0.7 ml. to 1.8 ml., the of this solution in ice, add 5 ml. of ly0 sodium nitrite solution, phenols are separated from 25 ml. aliquots of this solution and ~ n dilute d t o 100 ml. with ice water. Preserve in an ice bath. measured as the>- are from the smoke distillate. The concenSodium Carbonate-Impregnated Filter Paper. Spray sheets tration of each phenol in the smoke is then calculated from the of IYhatnian $1 filter paper, 46.5 X 5 i cin., to fiber saturation average maximum values found for the known and that from the n-ith 1% sodium carbonate solution and air dry. smoke distillate using the following equation: Developing Solvent. Mix 100 nil. of ether (U.S.P. grade), 100 .ll)sorbance of unknown X -mg in 250 nil. solution nil. of petroleum ether (boiling range 30-65’ C., analytical grade), L -known - -lbsorlxmce of kno\rn volume of smoke in liters and 40 ml. of 50% methanol. L-se the lower phase for conditioning t h e paper, and the upper phare :IS developing solvent, = nig. per liter of smoke
phenols in cigarette smol
