Abstract: An apparatus for single-component measuring of exhaust gas enables the mixture composition of an Otto engine to be determined, wherein a stream of the exhaust gas is cooled, cleansed of condensate, purified and then mixed with a purified air stream in a constant mixture ratio. The stream of the mixture, or a part of the stream of the mixture, is then reacted by burning so that the exhaust gas is completely oxidized by the air and the reacted mixture is then analyzed.

Abstract: A pulsed or discontinuous laser-enhanced flame ionization detector for detection of traces of hydrocarbons in gaseous samples. The use of a laser in conjunction with flame ionization significantly increases the ratio of electronically excited CH radicals to ground electronic state CH radicals thereby increasing the signal to noise ratio during measurement, thus increasing the sensitivity of the flame ionization detection method.

Abstract: A method of regulating fuel for a coke oven by a programmed heating method in which a change of the fuel supply rate contains at least one substantial reduction during the coal carbonization process in the coke oven, wherein the improvement comprises setting up a standard curve for the ethylene concentration or the tar concentration based on the operating conditions of the coke oven and the conditions of feed coal, measuring the ethylene concentration or the tar concentration in the coke oven gas generated in the carbonization chamber, and controlling the fuel supply rate so as to minimize the difference between the measured value and the standard value.

Abstract: Disposable cuvette for essentially simultaneous sampling of a fluid and analyzing the sample. The new cuvette comprises a body member having at least one cavity defined by surrounding walls, into which cavity the sample is permitted to enter by capillary force through an inlet communicating said cavity with the exterior of the body member. According to the invention, the cuvette is characterized in that at least a portion of the walls facing the cavity consists of a semipermeable membrane, optionally with an integrated electrode and/or sensor system, and that at least one reagent or reagent system is incorporated in the cuvette.

Abstract: Serum is passed through a column containing silica gel alkylated with lower alkyl groups. The column is then washed with diluted acid and water, and the digoxin eluted with aqueous methanol at a volume less than about the volume of the serum to provide a digoxin concentrate that may be used in assay determinations.

Abstract: An article for testing liquid for free fatty acid comprises a substantially nonreactive, neutral and non-buffering, porous, absorbant support material having at least one portion thereof which contains a composition comprising an effective amount of acid-base indicator capable of changing color, when the predetermined amount of base has reacted with the known amount of free fatty acid, in a pH range on the order of 6-10, a predetermined amount of base compound reactive with free fatty acid and being present in an amount equivalent to a known concentration of free fatty acid, and about 30-99.5 parts by weight of non-volatile material of a substantially colorless, substantially neutral, humectant polyalkylene glycol organic solvent which is substantially non-volatile under ambient conditions. An organic liquid to be tested is contacted with the article and any color change in the article after the passage of sufficient time is observed.

Abstract: A method is disclosed for separating and measuring the fluorescence of 4-carboxy-p-terphenyl in crude terephthalic acid formed by the liquid-phase oxidation of p-xylene in a solvent.

Abstract: Serum is passed through a column containing alkylated silica gel. The column is then washed with a mixture comprising from about 50 to 85 volume percent of an aqueous buffered medium of pH from about 3.5 to 5.0 and from about 15 to 50 volume percent of an organic solvent containing from 1 to 6 carbon atoms and from 1 to 5 heteroatoms selected from the group consisting of oxygen, nitrogen, and sulfur. The tricyclic antidepressant drug is removed from the column with an eluent mixture comprising from about 0 to 75 volume percent of an aqueous buffered medium of pH of about from 6 to 8 and from about 25 to 100 volume percent of one or more organic solvents containing from 1 to 6 carbon atoms and from 1 to 5 heteroatoms selected from the group consisting of oxygen, nitrogen, and sulfur. In this way, a tricyclic antidepressant drug sample, free from interfering metabolites, for use in assay determinations is obtained.

Abstract: An electron capture detector for use with a capillary column is provided with a sample inlet comprising a tubular anode through which sample molecules and a make-up gas are introduced into the detector cell. The tubular anode has side ports for producing a plug-like flow inside the cell. The inner surface of the anode is protected by an insulating tube so that the capillary column can be extended to a point beyond the side ports without the fear of its electrical contact with the anode. This allows the sample molecules to flow nearly entirely in the center section of the cell. The peripheral regions of the cell where a radioactive foil is disposed is swept nearly entirely by the make-up gas entering the cell through the side ports. This has the effects of reducing sample dilution by the make-up gas and sample loss due to contact with the detector walls.

Abstract: A stable test device capable of manufacture by automated methods for the determination of chloride in an aqueous fluid sample. The test device operates by controlled diffusion of the aqueous sample into a porous matrix. The matrix is incorporated with sodium carrageenan and silver salts capable of dissolving in an aqueous fluid containing chloride, at least part of which silver salts is silver chromate. Devices prepared with the inclusion of sodium carrageenan provide a chloride test device with approximately double the shelf life under room temperature storage conditions of previous test devices prepared without sodium carrageenan. The stable test device provides useful information in less than about 2 minutes after the sample contacts the matrix. The chloride concentration of the sample is determined by comparing the pattern of silver chromate remaining after sample contact to an appropriate pattern chart.

Abstract: A test means for determining the presence of an ion in an aqueous test sample, a method for preparing it and a method for using it. The test means comprises a hydrophilic carrier matrix incorporated with finely divided globules of a hydrophobic vehicle. The hydrophobic vehicle contains an ionophore capable of forming a complex with the ion and a reporter substance capable of interacting with the complex of ionophore and ion to produce a detectable response. The test means of this invention is useful for clinical determinations of serum potassium. The test means forms the reagent layer in a multilayer format which is particularly suited to whole blood electrolyte determinations and does not require washing or wiping before use.

Abstract: A gas chromatograph system is provided with an improved electrolytic conductivity cell (16) for detecting a selected material species in a fluid stream from conventional gas chromatograph (10, 12) having both gas and liquid phases. Planar electrodes (80, 82) are spaced by an insulator (84) and define borehole diameters (88, 90, 92) which enhance the generated signal-to-noise ratio by providing a short fluid transit time within the conductivity detecting volume compared with the effective time of the chromatographic event of interest. A pneumatic damper (108) may be further included to reduce generated system signal noise.

Abstract: A method is provided for determining the percentage of glycohemoglobin in patient whole blood. The method comprises subjecting total hemoglobin comprising non-carbohydrate fixed hemoglobin and glycohemoglobin of samples of (1) patient whole blood lysate P and (2) whole blood lysates K.sub.1 and K.sub.2 of known glycohemoglobin percentages %.sub.1 and %.sub.2, to batchwise selective adsorption on an adsorbent which is specific either for the hemoglobin or for the glycohemoglobin, thereby adsorbing each sample under the same conditions and leaving in solution the corresponding non-adsorbed total hemoglobin fractions P.sub.f, K.sub.1f and K.sub.2f. The ratios R.sub.p, R.sub.k1 and R.sub.k2 of the optical density of the total hemoglobin fractions P.sub.f, K.sub.1f and K.sub.2f to the respective optical density of total hemoglobin aliquot samples of lysates P, K.sub.1 and K.sub.2 are measured, and the percentage of glycohemoglobin relative to total hemoglobin for each patient blood sample is calculated.

Abstract: A test kit for preparing a chemical test pad used in testing for the presence of occult blood in a specimen. The test kit is a foil package enclosing an absorbant pad bearing a peroxygen agent and a solution of guaiac in alcohol in a separate packet or compartment from the absorbant pad. The separate packet or compartment being rupturable by applying hand pressure to the outside of the foil package to mix the peroxygen agent powder on the test pad and the guaiac solution prior to removing the absorbant pad from the foil package. The method relates to performing a medical test by activating a test pad bearing one reagent by applying another reagent thereto while remaining wholly within a protective foil package. According to the method a test pad containing the peroxygen agent is wetted with a solution of guaiac in alcohol prior to removal from the protective foil package and exposure to a specimen of fecal material and water in a test for occult blood.

Abstract: A new Karl Fischer reagent contains as a pyridine substitute at least one compound of the general formula ##STR1## in which R.sup.1 and R.sup.2, which can be identical or different, =hydrogen or alkyl having 1-6 C atoms,R.sup.3 =alkyl having 1-6 C atoms,X=alkali metal ion or one equivalent of an alkaline earth metal ion,n=0 or a number from 1 to 4 andm=a number from 1 to 4.

Abstract: A test means, test device and method for use for determining the presence of an ion in a test sample are disclosed. The test means comprises a substantially nonpolar, nonporous carrier matrix incorporated with an ionophore capable of forming a complex with the specific ion and reporter substance capable of interacting with the complex of ionophore and ion to produce a detectable response. The test means disclosed is particularly useful for serum potassium determinations. The test means forms the reagent layer in a multilayer format particularly suited to whole blood electrolyte determinations.

Abstract: The determination of fructosamine levels in at least part of a blood sample for use in detecting diabetes in patients or deciding treatment levels is effected by controlling the temperature and pH of the sample, adding a coloring agent such as a nitro-blue tetrazolium and after a first delay in time taking a first color measurment at a predetermined wavelength and after a second delay in time taking a second color measurement at the predetermined wavelength, then comparing any resultant change between the first and second color measurements with those of standard solutions, the selected timing delays, wavelength, coloring agent and pH conditions being such that any change of color in the coloring agent between the first and second color measurements is caused predominantly by the glucose in the sample that is reacted with an amine group of protein and has undergone a molecular rearrangement to form fructosamine and not materially by any non-specific reducing substance which may be present in the sample.

Abstract: An indicator capable of determining whether the concentration of a disinfectant/sterilant solution of glutaraldehyde exceeds a predetermined value comprising an indicator medium impregnated with a sulfite compound and an amino acid or an ammonium salt.

Abstract: The determination of fructosamine levels in at least part of a blood sample for use in detecting diabetes in patients or deciding treatment levels is effected by controlling the temperature and pH of the sample, adding a coloring agent such as a nitro-blue tetrazolium and after a first delay in time taking a first color measurement at a predetermined wavelength and after a second delay in time taking a second color measurement at the predetermined wavelength, then comparing any resultant change between the first and second color measurements with those of standard solutions, the selected timing delays, wavelength, coloring agent and pH conditions being such that any change of color in the coloring agent between the first and second color measurements is caused predominantly by the glucose in the sample that is reacted with an amine group of protein and has undergone a molecular rearrangement to form fructosamine and not materially by any non-specific reducing substance which may be present in the sample.

Abstract: A method and device for determining the clotting time for a sample of whole blood. A sample of whole blood is placed in a cuvette (12) which is centrifuged in a centrifuge (11) to mix the blood sample with a coagulant in the cuvette (12) and simultaneously spin out the cells in the blood. The optical density of a part of the sample which is cleared of cells by the centrifugation is monitored using a light source (14) and a light detector (15) and the time measured for optical density indicative of clotting to be reached by a timer (25).