stability and noise prevention in service station grease. Vekser and Rodzaevskaya (1470) determined syneresis of grease by a centrifugal method. Froeschmann (580) reported the results of comparative tests of the corrosion protective behavior of grease in different corrosion test machines. Knott et al. (?’,OD) described a water spray resistance tester comprised of a temperature controlled water bath, a gear pump, spray head, mount for the test panel, and a shield.
R. T. Edwards and D. R. Cushman, Mobil Oil Corp., Paulsboro, N. J.
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of wax laminations and heat seals was examined by Moyer and Zmitrovis ( 2 l F ) and the factors leading to seal strength or failure were discussed. Finck ( S F ) described new measurements of hardness of waxes using a modified Haake consistometer. He developed new values of “absolute hardness” by correcting for the contact area with wax and by extending the testing time. Spengler and Wilderotter (26F) measured the penetration of spheres and cones into various waxes as a function of temperature and established a correlation by means of which the plastic state of waxes could be described. Fabian, Mozes, and Vamos ( 2 F ) proposed rheological parameters for characterizing the consistency of a petrolatum below the dropping point. Factors affecting the breakdown and regeneration of the quasi-plastic structure were discussed. A color testing method based on the Pulfrich photometer for wax stocks used to make cosmetic and pharmaceutical products was described by Fischer and Keil (4F). Krupskii and coworkers (13F) measured the thermal conductivity of paraffin wax a t low temperatures. Differential thermal analysis was used by Lange and Jochinke (14F) to characterize waxes and wax mixtures including synthetic products. Work has continued on testing of waxes for carcinogenic polycyclic aromatic hydrocarbons. Howard and Haenni (108’) used paper chromatography to separate polynuclear hydrocarbons extracted from wax by dimethyl sulfoxide. Paper chromatography was repeated until extracts from the cut-out bands gave significant spectral peaks. The same authors (11F) used column chromatography with Magnesia-Celite to separate compounds from a dimethyl sulfoxide-phosphoric acid extract from a solution of wax in an aliphatic solvent. Helberg ( 7 F ) continued his work with a paper chromatographic procedure. Lijinsky and coworkers (1627) used gas chromatography with an electron-capH E PERFORMANCE
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ANALYTICAL CHEMISTRY
ture detector to detect polycyclic aromatics in an extract from wax. Jaforte and Cavallero ( 1 I F ) extracted wax with methanol and cooled the filtrate to precipitate paraffinic hydrocarbons prior to spectroscopic analysis of the extract. Hofmann (9F) summarized specifications and testing methods required in Germany and the U.S.A. for liquid petrolatum, hard paraffin wax, and microcrystalline waxes used in foods, drugs, and/or food packaging. Three papers dealt with the measurement of oil content of wax. Lizogub and coworkers (17F) used an optical analyzer employing modulated radiation from a hydrogen lamp and a photocell. The same authors ( I F ) in a later paper described the AMP 2 analyzer (presumably the same instrument) for oil content determination. Triems and Heinze (26F) determined oil in microcrystalline wax using an acetone-benzene-toluene mixture, cooling, and washing the precipitate with fresh cold solvent. Tronov and Khamzina (27F) determined neutral resins in samples of petroleum and industrial paraffin. After removing asphaltenes, optical density of the filtrate was compared to a control from which the resins had been removed with silica gel. A nomograph for the estimation of paraffin wax composition was developed by Melpolder, Turner, and Wilbur (20F). I t is based on the relationship of melting point, refractive index, and viscosity to chemical composition of the wax. Raouf, Triems, and Heinze (I@) determined the composition of crude waxes obtained by fractional dewaxing of a neutral oil by n-d-hf analysis, urea adduction, and column chromatography to determine optimum dewaxing (deoiling) temperature. Three papers dealt with gas chromatography. Hildebrand et al. (8F)used high temperature gas chromatography to study chain length distribution of n-alkanes in lignite wax. The concentration of odd numbered was greater than that of even numbered n-alkanes. Ludwig (19F) separated n-alkane homologs in the urea adductible fractions of various waxes by gas-liquid chromatography reporting data up to a carbon number of 67. Van der Wiel (28F) used molecular sieves to separate normal and branched paraffins and determined carbon number distribution of the two fractions by gas chromatography. Guseva and Leifman (6F) followed the crystal structure of narrow fractions of paraffins, obtained by urea adduction, as a function of temperature by means of refractive index measurements in the liquid and solid states. Ludwig (18F) analyzed films of waxes in the solid and molten states by means of infrared spectra and differentiated microcrystalline from paraffin waxes by changes in inten-
sity of CHTchain rocking absorptions at 13.7 and 13.9 microns and other measurements. Polyakova and coworkers (25F) reported on the mass spectrometric analysis of paraffin waxes. By modifying earlier methods to fit the instrumentation available, to correct for differences in relative ionization sensitivities, they could determine normal, iso-, and cycloparaffins and molecular weight distribution of the normal paraffins in waxes of predominantly normal paraffin type. Gabrielli and Puggelli (5F) used a monolayer method to determine the molecular weight of a paraffin. Measurements of the monomolecular film (expanded or condensed) on various solutions yielded values in agreement with cryoscopic data. Lindeman and Nicksic (168’) studied the phase behavior of oil in commercial waxes by means of nuclear magnetic resonance. The effects of molecular weight distribution of the wax and other factors were discussed. Under selected conditions, oil contents correlated with the ASTM D721 method but nuclear magnetic resonance values were consistently lower. Nyul, Juhos, and Furedi (22F) reported on analyses of petrolatum by adduct formation. The semiparaffins form no adduct with urea or thiourea, but can be separated by solvent dewaxing and make the major contribution to product properties. The T-paraffins form adducts with thiourea but not with urea. Analyses of high quality U.S. petrolatums were given.
Asp halt John A. Wronka, Cities Service Oil Co., Cranbury, N. J.
H
(36GS8G) is editing a three-volume treatise concerning itself with asphalts, coal tars, and pitches with Vol. I, Vol. 11, Part 1, and Vol. I11 completed. Redfield et al. (TSG) described a proposed ring and ball test for asphalts, tars, and pitches softening between 35” and 150” C; Schmidt and Santucci (78G) described a falling-plunger viscometer for determining asphalt viscosity a t low temperatures; and Griffith (29G) reported recent progress in the development and specification of fundamental viscosity measurements to replace empirical tests for asphalt cements. Kofalt (48G) reported that a single viscosity specification for a specific penetration grade cannot cover asphalts from all sources and Mapstone (6fG) presented tables and nomograph for determining the asphalt penetration with a penetrometer weighing 50-250 grams from a known penetration with a 100-gram penetrometer and for deterOIBERG
