Richard E. Kupel

A Convenient Optimized Method for the Analysis of Selected Solvent Vapors in the Industrial Atmosphere

Industrial hygienists have generally sampled for industrial solvent vapors either by taking grab samples or by measuring the concentrations with bulky equipment such as the Davis halide meter. A convenient method is described for the determination of solvent vapors in atmospheric samples. A glass tube packed with activated charcoal is used to take an integrated sample. A standard volume of 10 liters is sampled, and the tube is capped and returned to the laboratory for analysis. The activated charcoal is desorbed with carbon disulfide, and an aliquot is introduced into a gas chromatograph equipped with a flame ionization detector. Optimum operating conditions have been established on the gas chromatograph for the separation and analysis of selected solvent vapors of occupational health interest. Data are presented on both the adsorption and the desorption efficiencies of selected solvent vapors, determined by this method. The solvents were benzene, n-butyl acetate, 2-butanone, carbon tetrachloride, chlorof...

The identification of toxic compounds in the pyrolysis products of polytetrafluoroethylene (PTFE).

Abstract When polytetrafluoroethylene (PTFE) was pyrolyzed in air in the temperature range of 500° to 650°C (932° to 1202°F), the predominate product was COF2. Above 650° C the major products were CF4 and CO2. Other fluorocarbons were produced in lesser amounts. PTFE pyrolyzed in the presence of SiO2 also formed SiF4. Between 550° and 600°C production of COF2 was as high as 63%. Experimental exposure of rats showed COF2 to be the most toxic component of the pyrolysis gases.

Characterization and Solubility of Metals Associated with Asbestos Fibers

Abstract A series of uniform samples representing blends from different sources and types of asbestos were analyzed for nickel, chromium, cobalt and manganese. The bulk samples and the less than 10-micron size fractions were analyzed separately. The metals soluble in bovine serum were determined for the less than 10-micron fractions. Free silica content was also determined. The degree of solubility of the same metal varied considerably by source and type of asbestos. Chrysotile had greater amounts of nickel and chromium whereas Amosite was higher in manganese. Crocidalite had the lowest metal content.

Qualitative detection limits for specific compounds utilizing gas chromatographic fractions, activated charcoal and a mass spectrometer.

Qualitative identification of gas chromatograph (G.C.) fractions has created problems for the organic chemist. One of these concerns the limit of detection for any given compound which can be achieved with a method designed to trap a G.C. peak for further analysis. This paper presents the limits of detection found attainable in the qualitative analysis of specific organic compounds. These limits were established by utilizing an activated charcoal capillary to trap the G.C. fraction prior to introduction into a Bendix Time-of-Flight mass spectrometer via the hot filament probe.

Spectrochemical Determination of Indium and Antimony in Biological Materials

Abstract A spectrographic method for the determination of microgram amounts of indium and antimony in biological material is described. Samples are wet-ashed with nitric acid. An HCl solution containing 2 mg of ash is loaded on waterproofed electrodes charged with 5 mg of spectroscopic buffer and the gallium internal standard. The solution is evaporated to dryness in the electrode crater at 105°C. Electrodes are excited in a 220-voIt d-c arc. Spectral lines used are Ga 2943.6 A, Sb 2877.9 A, and In 3039.3 A. Concentrations as low as 1 ppm indium and 50 ppm antimony in 2 mg of ash can be determined. Mean coefficient of variation for indium is 10.9%, that for antimony is 9.9%.

Determination of sulfur dioxide by adsorption on a solid sorbent followed by ion chromatography analysis

A method for sampling and analysis of atmospheres for sulfur dioxide is presented. This method is based on adsorption of sulfur dioxide on an impregnated charcoal sorbent followed by desorption and analysis by ion chromatography. The precision and recovery of the sampling and analytical method were determined at 2, 1, 0.5 and 0.1 times the present OSHA standard of 5 ppm.

Separation and analysis of the less than 10-micron fractions of industrial dusts.

Abstract A procedure is reported for separating the minus-10-micron fractions of industrial dusts so that the chemical and physical natures of the components of these respirable fractions can be characterized. The procedure has been applied to bulk asbestos samples, and a comparison of the metallic compositions of the bulk, the plus-10-, and the minus-10-micron fractions is presented.

Quantitative Analysis of Polyvinylpyrrolidone in Atmosphere Samples and Biological Tissues

Abstract A quantitative method for the analysis of polyvinylpyrrolidone (PVP), collected in atmospheric samples or extracted from biological tissues, is described. PVP is a component in many aerosol hair sprays. A 0.4M citric acid solution is used to collect or extract the PVP. The color is developed by using a potassium iodide reagent, and the intensity of the color is read on a spectrophotometer at a wavelength of 432 mμ. The low limit of detection for this method has been established at 0.5 μg of PVP per milliliter of final solution.

Experimental Method for Evaluating the Decomposition of Fluorocarbon Plastics by Heat

Abstract In studying the toxicity of pyrolysis products of fluorocarbons, a time-of-flight mass spectrometer was selected for identification of decomposition fragments. Quantitative measurements were made by gas chromatography except for COF, which was collected in 0.5 N NaOH followed by determination of the fluoride. Monel metal tubes were used in the pyrolysis furnaces and temperatures were measured by thermocouples shielded with stainless steel. A cubical chamber (aluminum) of 1245-liter capacity and equipped with an airlock was used for exposure of animals to the pyrolysis products.

Qualitative Limits of Detection of Specific Compounds Obtained by Trapping Gas Chromatograph Fractions with an Activated Charcoal Capillary and Analyzing with the Mass Spectrometer

Qualitative identification of gas chromatograph. (G.C.) fractions has created problems for the organic chemist. One of these concerns the Limit of detection for any given compound which can be achieved with a method designed to trap a G.C. peak for further analysis. This paper presents the limits of detection found attainable in the qualitative analysis of specific organic compounds. These limits were established by utilizing an activated charcoal capillary to trap the G.C. fraction prior to introduction into a Bendix Time-of-Flight mass spectrometer via the hot filament probe.