Chromatographic Separation and Identification of Photographic Developers JAMES H. PAKNELL AND JATtIES E. L U V A L L E Technical Operations, Znc., iirtington, Mass.
course of a study of reactions of photographic developers, I-it became necessary to devise methods for the separation and of the developers and their oxidation products. v
THE
identification Knowledge of the reactions of developers was seriously limited by a dearth of information on such separations. A method based on paper chromatography was evolved which should be of value as it has the advantages of simplicity and specificity. However, it is probably applicable only to substances which are moderately stable to air.
Table I. R/ Values of Some Photographtic D e v e l o p e r s Hydroquinone disulfonate p-Methylaminophenol monosulfonate Hydroquinone monosulfonate Quinone monosulfonate p-Aminophenol hydrochloride p-Phenylenediamine hydrochloride p-Methylaminophenol sulfate Hydroquinone
0.00 0.09 0 15 0 34 0 43 0 5.5 0 61 0 80
layer is separated and used. .4s spray reagent, a 2% solution of ammoniacal silver nitrate gives the highest sensitivity. A 5% solution of phosphomolybdic acid, while less sensitive, produces chromatograms which do not darken with time. Best results are obtained when 10 y amounts of developers are used, although 1 y can be detected. Table I shows R/ values obtained by descending developmenton JVhatman S o . 2 paper using butanol-acetic acid-water solvent at room temperature (22’ C.) where the solvent front moved 40 cm. Previous published work available gives the datum only for hydroquinone (2), of the substances tabulated, with an RJ value of 0.88 obtained under similar conditions.
R I,
ACKNOWLEDGMENT
& 0.01
f 0 01 f 0 02 4= 0 03 i 0 03 f 0 02 i 0 02
This investigation was sponsored by the Air Research and Development Command under Air Force Contract KO.AF18 (600)-3i1. LITERATURE CITED (1)
The method employs standard chromatographic equipment and a solvent composed of butanol, acetic acid, and water ( I ) , mixed in the volume proportion 4 to 1to 5, fromwhich the organic
Bate-Smith, E. C., Biochem. SOC.Symposia (Cambridge, Enol.),
3, 62 (1949). (2) Block, R. J., “Paper Chromatography,” p. 124, New York. dcademic Press, 1952. RECEIVED March 19, 1953. Accepted July 2, 1953.
Spectrophotometric Determination of Glycerol as Sodium-Cupri-Glycerol Complex FRANK SPAGNOLO Research Laboratories. National Lead Co., Brooklyn, !V. Y .
investigation of the analysis of glycerol-containing mateIrials, the literature revealed a method by Bertram and Rutgers (1)based on the formation of the sodium-cupri-glycerol comv
AN
plex and its subsequent iodometric determination. A later method published by Whyte ( 4 ) describes the determination of glycerol by spectrophotometric measurement of the blue-colored sodiumcupri-glycerol complex. On analyzing various glycerol-containing materials in the writer’s laboratory, it became desirable to further increase the sensitivity of the spectrophotometric method for application to smaller working quantities of glycerol than employed by Whyte, and to test the application of such a method to products not previously analyzed by the spectrophotometric method. Accordingly, a modified procedure was developed whereby 1. Sensitivity is increased by use of absorption cells of longer light path. 2. Titration of the glycerol solution with cupric chloride reagent to a faintly perceptible turbidity is eliminated by use of a definite amount (6.0 ml.) of reagent and a working aliquot of solution t o contain 17 to 65 mq. of glycerol for the color development. This modification in effect reduces operating variables between analysts. 3. The method can be applied t o products not previously examined, such as glycerol esters and resinous vehicles.
Condensers, water-cooled, to fit Erlenmeyer flasks. Buret, for delivering the cupric chloride reagent. pH meter or Universal-type pH paper. REAGENTS
hqueous sodium hydroxide solution containing 21.0 grams of sodium hydroxide ( 3 ~ 0 . 2gram) per 100 ml. Ethyl alcohol, 95%, reagent grade or formula 3A. Cupric chloride reagent. Dissolve 10.0 grams (fO.l gram of cupric chloride dihydrate) reagent in 95% ethyl alcohol and dilute to 100.0 ml. Benzene, reagent grade. Dissolve 66.0 grams of reagent Potassium hydroxide, 1.0 J\-. grade (85%) potassium hydroxide in 95% alcohol and dilute to 1 liter. Hydrochloric acid, reagent grade. Ethyl ether, reagent grade. Glycerol, reagent grade. Determine purity by the American Oil Chemists’ Society’s specific gravity method No. E.4-7-50, and apply the necessary gravimetric correction. PRODEDURE
Preparation of Standard Calibration Curve. Pipet into 100ml. volumetric flasks various volumes of an aqueous stock solution of glycerol to contain 17 to 65 mg. of glycerol. (At least 5 or 6 aliquots should be taken for the calibration.) Add distilled water to bring the volume to 10.0 ml. Add 10.0 ml. of 21% sodium hydroxide solution, and 60 ml. of ethyl alcohol. rldd slon-ly from a buret, 6.0 ml. of cupric chloride reagent with vigorous swirling. Stopper, shake vigorously for 2 minutes, and dilute to volume with ethyl alcohol. Transfer a well-mixed portion of the colored mixture to a 50ml. centrifuge tube, stopper, and centrifuge a t a relative centrifugal force (r.c.f.) of 420 for 10 minutes. (R.c.f. = 28.6 n * ~ , where n = 1000 X r.p.m., and r = distance in inches from the center of rotation to the center of gravity of the solution.) The time required for sedimentation can be decreased by increasing
APPARATUS
The Beckman Model DU spectrophotometer, equipped with 5.0-cm cells. Volumetric flasks, lOO-ml., 200-ml., and various other sizes. Volumetric pipets various sizes. Separatory funnefs, 250-ml., pear-shaped. Centrifuge, equipped with 50-ml., rubber-stoppered tubes. Erlenmeyer flasks, 200-ml., glass-stoppered, 24/40$, with pourout lip. 1566
