Abstract: A process for measuring the mercury concentration within a hydrocarbon is provided that enables the mercury concentration to be measured simply and quickly, and with good reliability and good reproducibility. A process for measuring the mercury concentration within a hydrocarbon includes the steps of placing and weighing the hydrocarbon in a sample boat 12 containing an adsorbent that contains a metal capable of forming an amalgam with mercury, and heating the hydrocarbon inside the sample boat 12 in a combustion furnace 13, together with the adsorbent, and measuring the quantity of mercury within the thus generated gas.

Abstract: A catalytic testing device comprising a reaction block comprising a set of reaction chambers, each chamber comprising a fluid inlet and outlet connected to an outgoing fluid duct connected to analysis means, fluid feed means capable of performing regulated dosing of flows of the fluid at the required pressure independently in each of the reaction chambers, automatic and dynamic pressure control means, capable of performing pressure regulation in each reaction chamber, which comprise a non-return valve in the outgoing fluid duct between the outlets of the reaction chambers and a common regulating tank that receives the outgoing fluid from the chambers, a pressure sensor provided in a first outlet duct and an automatic needle valve provided in a second outlet duct from the tank.

Abstract: Apparatus and method for determining incomplete combustion in a combustion analyzer comprising a combustion chamber (60). A sample is supplied to the combustion chamber and combusted to produce combustion products. A target gas characteristic of incomplete combustion of the sample is detected in the combustion products by a target gas sensor (72). The target gas may be carbon monoxide, methane, methanal and/or methanol, among others. Preferably, the gas sensor is an electronic or catalytic combustible gas sensor. Whether incomplete combustion of the sample has occurred may be determined. A signal indicative of incomplete combustion is output from the target gas sensor to a controller (78). The combustion products can be directed to waste and/or further supply of the sample/oxygen may be stopped/adjusted. Faulty analysis measurements and/or contamination of downstream components, which would otherwise result from incomplete combustion—in particular, from soot formation—can thereby be avoided.

Abstract: A process and apparatus for testing material libraries, in particular catalysts, by means of coupled use of at least two analytical methods, preferably IR thermography and mass spectrometry. Owing to the selected arrangement, the disadvantages of the two previously known individual methods are compensated for: the subsequent selectivity determination for selected sections by means of mass spectrometry invalidates the argument against IR thermography, of only being able to determine activities; the rapid integrated determination of potentially “good” materials via IR thermography prevents an excessive loss of time by needing to test all materials of a library successively with the mass spectrometer.

Abstract: A method is provided for the quantitative analysis of the contents, in nitrogen, of hydrogen and methane by ionic mobility spectrometry. The method includes the steps of: a) performing a measurement of the apparent hydrogen concentration in the nitrogen to be analyzed; b) performing a measurement of the apparent hydrogen concentration in a flow of the same sample of nitrogen, purified of all impurities but methane; and c) comparing the two measurements. A system of branched lines is also provided for carrying out the method.

Abstract: An ionic liquid bound on an exposed surface of a device such as for detecting organic chemicals, preferably a gas sensor is described. The gas sensor can operate at high temperatures with a fast linear response which is also reversible. At high temperatures, the frequency change (?f) versus concentration (C) curve mirrors the Henry's gas law, such that the concentration of a gas sample in liquid solvent is proportional to the concentration or partial pressure of the sample in gas phase. A single gas sensor, or an array of sensors, can be used for the detection and quantitative analysis of gas vapors.

Abstract: A multi-pin chemiresistor for use in microchemical sensors. A pair of free-standing, bare wires is supported by an electrically insulating support, and are oriented parallel to each other and spaced closely together. A free-standing film of a chemically sensitive polymer that swells when exposed to vapors of a volatile chemical is formed in-between the pair of closely-spaced wires by capillary action. Similar in construction to a thermocouple, this “chemicouple” is relatively inexpensive and easy to fabricate by dipping the pair of bare wires into a bath of well-mixed chemiresistor ink. Also, a chemiresistor “stick” is formed by dipping an electrically insulating rod with two or more linear or spiral-wrapped electrical traces into the bath of well-mixed chemiresistor ink, which deposits a uniform coating of the chemically sensitive polymer on the rod and the electrical traces. These “sticks” can be easily removed and replaced from a multi-chemiresistor plug.

Abstract: Oil aging and particulate building in a lubricant other than one exposed to combustion products is monitored by detecting light transmitted through the lubricant at least one, and preferably, two or more preselected wavelengths over a pathlength greater than about 0.5 cm wherein one wavelength is in the near infra-red spectrum and/or one wavelength is in the visible or near infra-red spectrum. The detected light when compared to predetermined values provides an indication of the condition of the lubricant.

Abstract: A method for quantitative determination of hydrocarbon species in a hydrocarbon sample is disclosed. The method uses Townsend Discharge Nitric Oxide Chemical Ionization Gas Chromatography/Mass Spectrometry.

Abstract: The present invention relates to assays for ascribing catalytic activity to rock samples by virtue of zero-valent transition metals potentially being present within the sample. Embodiments of the present invention are generally directed to novel assays for measuring intrinsic paleocatalytic activities (k) of sedimentary rocks for converting oil to gas and projecting the activities to the subsurface based on the measured linear relationship between ln(k) and temperature (T).

Abstract: The invention relates to an automated method for carrying out reactions with high spatial resolution on libraries of different materials and for analysis of the products obtained using a simple robot system and an analyzer, for example a mass spectrometer.

Abstract: The object of the invention is to propose a novel biomarker for stress states, which biomarker is highly meaningful and capable of enabling quantitative measurements to be made of stress levels. To do this, it has been found, surprisingly, that the air at the end of a person's breathing out, known as “alveolar” air, contains fluorine compounds when that person has been subjected to various stress states. More precisely, the present invention provides components based on fluorine compounds, in particular fluorinated chloroalkanes, used as biomarkers of stress states.

Abstract: An inverse analysis method for characterizing diffusion of vapor from an underground source of volatile contaminant using data taken by an in-situ sensor. The method uses one-dimensional solutions to the diffusion equation in Cartesian, cylindrical, or spherical coordinates for isotropic and homogenous media. If the effective vapor diffusion coefficient is known, then the distance from the source to the in-situ sensor can be estimated by comparing the shape of the predicted time-dependent vapor concentration response curve to the measured response curve. Alternatively, if the source distance is known, then the effective vapor diffusion coefficient can be estimated using the same inverse analysis method. A triangulation technique can be used with multiple sensors to locate the source in two or three dimensions. The in-situ sensor can contain one or more chemiresistor elements housed in a waterproof enclosure with a gas permeable membrane.

Abstract: An object of the present invention is to provide a reagent for activating and unmasking antigens in a immuno-tissue-chemical staining. A slice of tissue cells on a slide glass is heated or heated under pressurization by an electric pot, autoclave, microwave oven, scalder, or constant-temperature bath for a sufficient time period in CCA aqueous solution of suitable pH and CCA concentration, thereby activating and unmasking antigenicity of antigen masked by aldehyde fixation.

Abstract: The present invention relates to a method and an apparatus for analyzing trace impurities in gases, which enable to analyze a very small quantity of impurities by only a simple operation, without making the column arrangement or the structure of flow complicated. In the apparatus and the method, when the trace impurities are measured in ppb-sub ppb level by a combined analyzer which is equipped with an atmospheric pressure ionization mass spectrometer to the back of a gas chromatography, a mixed gas of various gases is used as a carrier gas or purified gases added to the gases outflowed from a gas chromatography.

Abstract: A process is described for determining the stability of asphaltenes in oil fields, which comprises the following steps: a) titrations of stock tank oil are carried out; the values measured are then used, together with physico-chemical analyses of the stock tank oil, to thermodynamically characterize the asphaltenes and the heavy oil fraction; b) using the physico-chemical analyses of live oil, the experimental data relating to its phase behavior are interpolated in order to provide a better representation by means of an equation of state; c) using the equation of state thus calibrated and the characterization of the asphaltenes, the stability of the latter is verified in relation to the temperature and pressure of live oil, using the equation describing the behavior of a sterically stabilized colloid.

Abstract: An air-barrier agent for an aqueous reagent or an aqueous specimen having as an effective component a mixture of a chain hydrocarbon and a silicone oil immiscible with the aqueous reagent as well methods of using and making the same.

Abstract: Methods for evaluating catalysts, in which a multicell holder, e.g., a honeycomb or plate, or a collection of individual support particles, is treated with solutions/suspensions of catalyst ingredients to produce cells, spots or pellets holding each of a variety of combinations of the ingredients, is dried, calcined or treated as necessary to stabilize the ingredients in the cells, spots or pellets, then is contacted with a potentially reactive feed stream or batch, e.g., biochemical, gas oil, hydrogen plus oxygen, propylene plus oxygen, CCl2F2 and hydrogen, etc. The reaction occurring in each cell can be measured, e.g., by infrared thermography, spectroscopic detection of products or residual reactants, or by sampling, e.g., multistreaming through low volume tubing, from the vicinity of each combination, followed by analysis, e.g., spectral analysis, chromatography, etc., or by observing temperature change in the vicinity of the catalyst, e.g.

Abstract: A test for determining the bioavailable fraction of an organic pollutant present in soil comprises determining the fraction of the organic pollutant present in the soil which may be extracted by a cyclodextrin or derivative thereof.

Abstract: The invention includes systems and methods which allow reactivation of supported noble metal catalysts. The method involves heating the catalyst in the presence of a gaseous hydrocarbon in the absence of oxidizing agents. Systems of the invention provide for in situ reactivation of catalytic material.

Abstract: A method of assessing a psychiatric or neurological condition such as schizophrenia comprises measuring the presence and optionally the amount of butane (and optionally ethane) in the expired breath of the subject. In certain preferred embodiments the variation in the levels of butane is used as an indicator of the presence and optionally the severity of the condition.

Abstract: In this method of analyzing a gas mixture containing at least one inflammable gas to determine its explosibility, a resistive heating element (15) is energized in an analysis enclosure (12) communicating with the gas mixture to be analysed to burn the gas mixture in the enclosure, an electrical signal (S) at the terminals of the resistive element (15) is measured during combustion, and the explosibility of the gas mixture is determined from a comparison of values of the signal measured during a transient phase in which the concentration of the inflammable gas in the gas mixture is falling. The measurements taken during the transient phase are taken at times chosen to obtain, for different inflammable gases, substantially identical measurement signals for concentrations corresponding to identical explosibilities.

Abstract: The present invention provides methods for detecting the presence of an analyte indicative of various medical conditions, including halitosis, periodontal disease and other diseases are also disclosed.

Abstract: A method and apparatus are disclosed for analyzing the aggregate content of asphalt-aggregate compositions. The method includes placing a preheated, preweighed container carrying a sample of an asphalt-aggregate composition into a preheated furnace with the preheated furnace being warmer than the preheated sample, continuing to heat the furnace while drawing air through the furnace at a rate that avoids impeding the heating of the furnace or the sample until the sample in the container reaches its combustion temperature and the combustion of the sample becomes exothermic, initiating a second draw of air around rather than through the furnace to moderate the exterior temperature of the furnace, accelerating the draw through the furnace to increase the rate of combustion of the exothermic reaction, and reweighing the container and sample after combustion is complete.

Abstract: A method and apparatus are disclosed for analyzing asphalt-aggregate compositions. The method includes directing sufficient microwave radiation from a microwave source to a sample of an asphalt-aggregate composition to ignite the asphalt in the composition and to thereafter entirely combust the asphalt in the sample. The apparatus includes a source of microwave radiation, a cavity in communication with the microwave source, a sample holder in the cavity for holding a sample of an asphalt-aggregate composition during exposure to microwaves from the source, thermal insulation between the sample holder and the remainder of the cavity, and means for minimizing or eliminating any undesired combustion products generated by the burning asphalt.

Abstract: The present invention discloses a method for improving the speed and sensitivity of optical spectroscopic techniques for remote detection of trace chemical species in a carrier gas. The disclosed method can be applied to any optical spectroscopic detection technique whose sensitivity decreases as the total pressure of the sample decreases. The method employs an inert and non-absorbing buffer gas to supplement the pressure exerted by the carrier gas. This ensures that the total pressure of the sample, and hence sensitivity of the detection technique, remains high. The method is especially useful when measuring concentration of chemical species produced at small rates, and therefore should prove useful for rapid serial screening of combinatorial libraries of compounds.

Abstract: In the course of a method for the structural analysis of a chemical compound by data signals measured with the chemical compound being compared with calculated data, a first data signal is generated for at least one first compound having a structure which is similar to the assumed structure and has the same first substructure, but a different substituent Sv (instead of the substituent Sa of the compound being studied) in the substitution position; a second data signal is generated which constitutes the difference between the data from a second Sv-substituted compound and an unsubstituted (third) compound; a third data signal is generated which constitutes the difference between the data from a fourth Sa-substituted compound and an unsubstituted compound; a fourth data signal is generated from the first three data signals, and the measured data signal and the fourth data signal are compared with one another.

Abstract: The selectivity of response of resistive gas sensors to specific gases or vapors is improved by the selection of specified gas-sensitive materials which are not previously known for the applications described, which include detection of hydrocarbons in the presence of CO, H.sub.2 S, SO.sub.2, chlorine, NO.sub.2, CO.sub.2 (especially in low concentrations), CFC's, ammonia, free oxygen by determination of partial pressures, and numerous organic gases and vapors.

Abstract: A liquid hydrocarbon fuel composition comprises at least one tagging agent and a mixture of hydrocarbon components having boiling points in the range of about 100 degrees F. to about 800 degrees F. The tagging agent is present at a concentration in the range of from about 0.5 ppb to about 500 ppb. The tagging agent is elutable by chromatographic analysis of the liquid hydrocarbon fuel composition apart from the hydrocarbon components of the fuel composition. The tagging agent is formed from an organic compound containing elements found at natural isotopic abundance. Preferably, two or more tagging agents are employed in the fuel so that each fuel composition can be assigned a unique tagging agent composition. Analysis techniques are also disclosed.

Abstract: The invention provides a gas sensor for selective detection of hydrocarbons in low-oxygen gases, having a capacitive element and a gas-permeable sensitive layer as a dielectric. The sensitive layer is a precious-metal-doped zeolite which has a regular crystalline structure made of primary pores whose diameter is in the order of the gas-kinetic diameter of the gas molecules to be detected.

Abstract: A device for determining at least one petroleum characteristic of a geologic sediment sample placed in a boat, said device including a first heater heating said sample in a non-oxidizing atmosphere, a measuring component determining hydrocarbon-containing products released after feeding the sample into said first heater, a second subsequent heater heating said sample in an oxidizing atmosphere, a measuring component determining the amount of CO.sub.2 contained in effluents discharged from the two heaters, said CO.sub.2 measuring means include a cell for measuring continuously CO.sub.2 throughout heating of the first and second heaters and a measuring component determining the amount of CO contained in the effluents discharged from the two heaters, and thereby allowing determination of said petroleum characteristic.

Abstract: A method of determining or predicting a value P.sub.x of a property of a feed X to a steam cracking process or yield of said process, which method comprises measuring the absorption D.sub.ix of said material at more than one wavelength in the region 600-2600 nm, comparing signals indicative of said adsorptions or a mathematical function thereof with signals indicative of absorptions D.sub.im or mathematical function thereof at the same wavelength for a number of standards S in a bank for which the said property or yield P is known, and choosing from the bank at least one standard S.sub.m with property P.sub.m said standard having the smallest average value of the absolute difference at each wavelength i between the signal for the material and the signal for the standard S.sub.m to obtain P.sub.x, with averaging of said properties or yields P.sub.m when more than one standard S.sub.m is chosen. If desired the method can be used as such to control the steam cracking process by comparison of P.sub.

Abstract: An apparatus for on-line measuring physical property data of hydrocarbon products such as octane number, cetane number, density, vapour pressure and the like or gasoline/alcohol ratio, comprising means for providing (N)IR radiation in a predetermined spectral range; means for transmitting light at selected wavelengths in the (N)IR spectral region; means for delivering light from said transmitting means to a hydrocarbon product line; means for allowing an optical path length in the hydrocarbon product line; means for detecting the light transmitted through the said optical path; means for providing the obtained signal to be input to processing equipment for spectral analysis and correlating the spectral data to the physical property data of hydrocarbon products such as octane number, cetane number, density, vapour pressure and the like or gasoline/alcohol ratio.

Abstract: A method allowing fast assessment of at least one petroleum characteristic of geologic sediments from a sample of these sediments, said method comprising heating the sample in a non-oxidizing atmosphere, and which method comprises different temperature rise stages; determining at least three magnitudes S.sub.1r, S.sub.2a and S.sub.b representative of the quantity of hydrocarbons contained in said sample, and deducing at least one petroleum characteristic of the geologic sediment from these three magnitudes.

Abstract: A substrate carrying a first electrode and a second electrode, the first and second electrodes being disposed adjacent to one another, the first electrode being disposed between the substrate and a gas-sensitive component, the gas sensitive component comprising an n-type semiconductor, the gas-sensitive component having a resistance that is gas-dependent and temperature-dependent, and the second electrode being disposed between the substrate and a non-gas-sensitive component, the non-gas-sensitive component comprising a n-type semiconductor and a p-type semiconductor, the non-gas-sensitive component having a resistance that is temperature-dependent and that is not gas-dependent and wherein the n-type semiconductor of the non-gas-sensitive component is Ga.sub.2 O.sub.3 and the p-type semiconductor of the non-gas-sensitive component is ZrO.sub.2.

Abstract: The present invention is a method to determine the chemical concentration of one or more of a number of the constituent classes of a feed to a catalytic cracking process. These constituent classes which are referred to as "lumps", include 14 different molecular types in 4 different boiling range fractions. A specific lump will include all individual molecular components which are expected to react in a similar way in the catalytic cracking unit.

Abstract: The present invention relates to a method for determining at least one petroleum characteristic of a geologic sediment sample heated in a non-oxidizing atmosphere and an oxidizing atmosphere. The sample is heated to a first temperature value below 200.degree. C. for a predetermined period of time and then to a second temperature value ranging between 600 and 850.degree. C. according to a temperature gradient between 0.2.degree. C. and 50.degree. C./min. Carbon dioxide and carbon monoxide are continuously measured during the temperature stages in order to determine at least one petroleum characteristic, wherein said petroleum characteristic comprises a quantity of organic oxygen, inorganic oxygen, total organic carbon, or inorganic carbon.

Abstract: A method of evaluating at least on type of pollution characteristic in a soil sample contaminated by hydrocarbon compounds, a method wherein the soil sample is first heated in a non-oxidizing atmosphere, then in an oxidizing atmosphere. The method comprises several temperature rise stages from which at least five quantities Q.sub.0, Q.sub.1, Q.sub.2, Q.sub.3 and Q.sub.4 are measured, wherein the quantities represent concentrations of hydrocarbon compounds in the soil sample. At least one type of pollution characteristic of the sample is determined from quantities Q.sub.0, Q.sub.1, Q.sub.2, Q.sub.3 and Q.sub.4.

Abstract: The present invention relates to a process for indicating the presence of organic vapors comprising the steps of determining the color, absorption or emission spectra of a Pt--Pt double-complex salt of platinum or a neutral platinum complex in the absence of organic vapor, exposing said double-complex salt of platinum or a neutral platinum complex to a gaseous environment, determining the color, absorption or emission spectra of said double-complex salt of platinum or a neutral platinum complex after exposure to said gaseous environment, and comparing the color, absorption and/or emission spectra of said double-complex salt of platinum or a neutral platinum complex in the absence of organic vapor with the color, absorption and/or emission spectra of said double-complex salt of platinum or a neutral platinum complex after exposure to said gaseous environment to determine if there is a difference in the color, absorption and/or emission spectra.

Abstract: A transition metal oxide based calorimetric non-methane hydrocarbon sensor (100) is constructed by disposing a transition metal based catalyst (105), preferably chromium oxide (Cr.sub.2 O.sub.3), onto a carrier (101). A temperature measurement device (103) is positioned thermally coupled to the transition metal based catalyst (105). A preferred application includes sensing non-methane heavy hydrocarbons in an automotive exhaust gas stream (803) by exposing a transition metal oxide catalyst based sensor (805) to the exhaust gas stream (803) and providing a signal (811) indicative of a concentration of non-methane heavy hydrocarbons and carbon monoxide (CO). Then, exposing a compensating sensor (807) to the same exhaust gas stream (803) and providing a compensating signal (813) indicative of a concentration of carbon monoxide (CO). By combining the signal (811) and the compensating signal (813), a measure of non-methane heavy hydrocarbons can be provided.

Abstract: For identifying one of a plurality of known gases in a gaseous mixture ba on air a single catalytic transducer is placed in the gaseous medium. The catalytic transducer is heated to a lower threshold temperature at which the oxidizable gas is oxidized little or not at all and a first value of a parameter characteristic of the thermal state of the transducer is captured. The catalytic transducer is then heated to an upper threshold temperature at which the oxidizable gas oxidizes significantly in contact with the catalytic transducer and a second value of the parameter characteristic of the thermal state of the transducer is captured. Using a predetermined law, a response signal representative of the gaseous medium is produced from the difference between the second and first values of the parameter characteristic of the thermal state of the catalytic transducer. The catalytic transducer is allowed to cool below the lower threshold temperature and the above operations are repeated cyclically.

Abstract: An improved measurement cell and circuit for measuring the electrical characteristics of a liquid sample during exposure to radiation includes a glass cell formed of a main tube extending generally parallel to an elongated lamp emitting the radiation, and a pair of electrodes disposed axially within the sample tube. In the preferred embodiment, the ends of the cell are formed of glass twinbore tubing fused to the glass main tube, the bores retaining ends of the electrodes. Inlet and outlet tubes and a temperature sensing well may also be fused to the main tube. In an implementation for measurement of TOC in water by oxidation to CO.sub.2, the source comprises a low pressure mercury vapor lamp, and the electrodes are formed of solid Ti with catalytic TiO.sub.2 surfaces.

Abstract: A halogenated hydrocarbon (HHC) detector is formed from a silent discharge (also called a dielectric barrier discharge) plasma generator. A silent discharge plasma device receives a gas sample that may contain one or more HHCs and produces free radicals and excited electrons for oxidizing the HHCs in the gas sample to produce water, carbon dioxide, and an acid including halogens in the HHCs. A detector is used to sensitively detect the presence of the acid. A conductivity cell detector combines the oxidation products with a solvent where dissociation of the acid increases the conductivity of the solvent. The conductivity cell output signal is then functionally related to the presence of HHCs in the gas sample. Other detectors include electrochemical cells, infrared spectrometers, and negative ion mobility spectrometers.

Abstract: A process for the measurement of the level of radioactivity of a solid by contacting the solid with a chemically stable reactant fluid. The reactant fluid is converted by nuclear radiation to a chemically stable product fluid to an extent dependent upon the radioactive content of the solid. The amount of the reactant fluid converted into the product fluid is detected in order to determine the level of radioactivity of the solid.

Abstract: An analytical system for measuring the concentration of non-methane organic gases within a test sample including methane and non-methane component groups. In one version, a dual column analysis system utilizes a metal column and a porous layer open tubular (PLOT column to separate methane and non-methane organic gases (NMOG). The metal column captures non-methane compounds which are more easily thermally trapped on the metal column, generally higher molecular weight compounds and polar molecule, which prevents these compounds from contaminating the PLOT column. In another version, the system incorporates a single trap in the form of a porous layer open tubular (PLOT) column which the sample mixture is directed through and which traps the NMOG group through adsorption. The methane group passes through the trap and is vented to atmosphere or evaluated using a detector.

Abstract: A method for the identification of whether a lubricant in a compressor is an alkylbenzene or a naphthenic oil. This method comprises adding 3,3-bis (p-hydroxyphenyl) phthalide and observing whether there is an absence or presence of turbidity.

Abstract: A method for determining the concentration of a tracer, e.g. nitrogen-bearing marker dye, in a hydrocarbon liquid, e.g. gasoline. In the present method, a sample of the marked hydrocarbon liquid which is to be analyzied is prepared by adding a known volume of a nitrogen-bearing, "internal standard" thereto. The sample is then heated, preferably in a gas chromatograph, to vaporize, separate, and measure the dye and the internal standard. These measurements provide a ratio which is matched or compared to a predetermined, reference ratio which, in turn, is representative of a known concentration of the dye in the sampled hydrocarbon.

Abstract: A quantitative method including separating a mixture of olefins, aromatics, and saturates by supercritical fluid chromatography to obtain an eluent stream that over a first time period contains a mixture of olefins and saturates, and over a second time period contains aromatics, and passing the eluent first to an ultraviolet absorption detector (UV). Importantly, the eluent is irradiated in the UV detector at a wavelength capable of producing an ultraviolet absorbance response of olefins that is independent of specific olefins present, and preferably is substantially similar to a mass detector response for olefins. From a combination of UV and mass response, the mass of the olefins in the mixture of olefins and saturates can be determined. Thereafter, the eluent is passed to a mass detector whereby the mass of the mixture of saturates and olefins is determined and then the mass of the aromatics is determined.

Abstract: Reactions leading to insoluble sediments formation in distillate fuel are accelerated by forcing oxygen into solution in the fuel at pressures of between about 90 and 110 psig and then stressing the fuel under conditions of accelerated storage at temperatures of between about 40.degree. C. to 100.degree. C. The method then makes use of gravimetric determination of the total insolubles formed. The stability of the fuel over a period of time as well as its comparative stability to other fuels can then be predicted from the amount of insolubles formed. The method can be carried out by using a specialized pressure vessel.

Abstract: A method and apparatus for assessing the odor intensity of combustion gas produced from an internal combustion engine in which the odor intensity of combustion gas is obtained from the pH-value of an aqueous solution prepared from odor-producing substances, based on a predetermined relationship between pH-value and odor intensity. The odor intensity thus obtained strongly correlates with organoleptically evaluated odor intensity. Since the odor intensity of the gas is determined from the pH-value, the precision and the reliability of the odor intensity measurement are enhanced.