Microanalytical laboratory

The microanalyses were run by the Schwarzkopf Microanalytical Laboratory, Woodside, NY. The l%Rh/Al203 catalyst was obtained from Johnson Matthey. 

Analyses. Analyses of ash, carbon, and hydrogen by combustion, and nitrogen by Dumas or micro-Kjeldahl methods (17) were obtained from Schwarzkopf Microanalytical Laboratory, Woodside, N. Y. 11377. 

Organic carbon analyses were made in duplicate by a combustion train method in the Microanalytical Laboratory, School of Chemistry, University of Minnesota, and Kjeldahl nitrogen analyses were done in triplicate in the Minnesota State Board of Health Laboratory. Averages of the readings are used here (Table III and VI) and are rounded off to the second decimal. Carbonate was removed from the samples by treatment with 0.5N hydrochloric acid prior to the carbon analyses. 

Analytical Methods. Microanalyses (C,H,OCH3, C—CH3) were performed by Schwarzkopf Microanalytical Laboratory, Woodside, New York. 

Methoxylation of TMP samples was achieved by heating pulp fibres together with appropriate amounts of dimethyl sulphate in an equivolume solvent of water, ethanol and dimethoxyethane(74), methoxyl content of the pulp fibres being controlled by the amount of dimethyl sulphate added (Schmidt, J.A. Heitner, C. J. Wood Chem. Chem. Technol., In Press). Samples were analysed for methoxyl content by Scharwzkopf Microanalytical Laboratories, Woodside, New York. Analysis of the TMP samples for phenolic hydroxyl content was according to the method of Gellerstedt and Lindfors(76). 

Ash and Total Sulfur Analyses. Samples were removed from the specimens and submitted for ash and total sulfur analysis to Schwartzkopf Microanalytical Laboratory, Woodside, N.Y. 11377. For ashing, samples were burned under oxygen at 900-1000°C for ca one half hour. For sulfur, samples were treated with potassium metal to convert sulfur to sulfides, followed by conversion to methylene blue for spectrophotometrlc analysis (at 670 nm). Except for very small samples (less than 0.2mg), values for ash and sulfur have an uncertainty of ca 10% of the reported values. 

The greatest difficulty with the use of thermal analysis is that inherent to any new method--that of a shortage of prior experience on the part of most forensic scientists. However, since the method has been used in the polymer field for many years, it should be possible for the forensic laboratories to draw upon this reservoir of experience. In the interest of furthering this method, the Perkin-Elmer Microanalytical Laboratory would be prepared to help in demonstrating the capabilities of thermal analysis for forensic use. 

CpWIr3(CO)n was prepared as previously described (2). Diphenylacetylene (Aldrich) was used as received. Preparative thin-layer chromatography was carried out on (20 x 20 cm) silica gel Si250F plates (J.T. Baker). Infrared spectra were recorded on a Perkin-Elmer 1750 FT-IR spectrophotometer. H NMR (360 MHz) spectra were obtained on a Nicolet NT-360 spectrometer. Fast atom bombardment (FAB) mass spectra were obtained by the staff of the Mass Spectrometry Laboratory of the School of Chemical Sciences on a VG ZAB-SE mass spectrometer, using a matrix of dithioerythritol/dithiothieitol calculated masses are referenced to 184W and 193Ir. Elemental analyses were performed by the School Microanalytical Laboratory. 

An Orion research digital ion analyzer 510 equipped with a temperature compensation probe was used for all pH measurements. A Hewlett-Packard diode array 8452A spectrophotometer with a thermostatted cell compartment was employed for UV-vis spectra and for kinetic measurements. All C NMR spectra were recorded by use of a Varian 400 XL spectrophotometer. Elemental analyses were performed by E and R Microanalytical Laboratories. A VG 70-SE mass spectrometer with fast atom bombardment was used. 

Ash Content. Samples were removed from the specimens and submitted for ash analysis (Schwartzkopf Microanalytical Laboratory, Woodside, NY). Samples were burned in oxygen at 900-1000 °C for about 0.5 h. 

Chemical Analyses.—Routine CHN analyses were performed on all samples by the Microanalytic Laboratory in the College of Chemistry, University of California, Berkeley, USA. Some samples (given in Table 1) were fully analysed by Galbraith Laboratories, Inc. (Knoxville, TN, USA) C, H, N, As, F and O analyses being carried out. 

Microanalytical Laboratory, Imperial College of Science and Technology, London, England. 

In 1929, the first organic microanalytical laboratory in Canada (and one of the first in North America) was started in his Department, under the direction of the author, and graduate students and professors came from all parts of the Dominion to learn the specialized techniques of Fritz Pregl s procedures (which had been passed from Pregl to H. D. K. Drew and, from him, to the author). It was then that we discovered that all chemists can be divided into two groups— those who, unable to acquire the necessary... 

C7Hi6N0 C H2(N02)30H, analyzed by Clark Microanalytical Laboratory. Calcd. 

Molecular weight and carbon-hydrogen determinations were made by Schwarzkopf Microanalytical Laboratories, New York, New York. Molecular weight was determined in benzene by vapor pressure osmometry. 

Proton NMR spectra were obtained from a Varian T-60 spectrometer. The solvent used was 99.8% CDCl containing trime-thylsilane as a marker. Infrared spectra were obtained with a Beckman Acculab-6 spectrometer. The elementary analyses were determined by Elek Microanalytical Laboratories, Torrance, California. A Waters high pressure liquid chromatograph was... 

Physical and Chemical Analysis. Elemental analyses were done by Elek Microanalytical Laboratories, Torrance, California. Molecular weights were determined on a Mechrolab Model 301A Vapor Pressure Osmometer using THF as the solvent at 40°C. IR spectra were recorded at a concentration of 25 mg/ml in CH Cl using 0.5 mm NaCl cells on a Beckman Acculab 6 instrument. Proton and carbon-13 NMR spectra were obtained on a Varian XL-100 spectrometer operating at 100.1 MHz for proton or 25.2 MHz for carbon. Proton NMR was measured in CD Cl (central residue peak at 5.3 ppm). Carbon-13 NMR was measured in CDCl (central peak at 77.1 ppm). A sample of asphaltene (0.5 g) was dissolved in 2.5 ml of CDCl with 35 mg of Cr(acac) added to it. To obtain reliable quantitative results, a delay time of 4 sec after each 35° pulse and 0.68 sec acquisition time was used in the gated decoupling sequence. All chemical shifts were reported in ppm downfield from TMS. 

Physical Properties. Elemental analyses were determined by the Alfred Bernhardt Microanalytical Laboratories. Molecular weights were determined with a vapor pressure osmometer (Mechrolab) with pyridine as the solvent. 

Mieroanalyses reported in this paper were performed by Miss Emily Davis, Miss Rachel ICopel, and by the Clark Microanalytical Laboratories, Urbana, Illinois. 

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