Abstract: Improved Karl Fischer reagents of the two-component type are described which eliminate problems such as inaccurate results and false end-points during titrations to determine the water content of a sample. The two-component reagent includes a vessel solution and a titrant solution, where the sample is added to the vessel solution and is titrated with the titrant in order to determine the water content of the sample. The improved vessel solution is one containing an amine such as diethanolamine or imidazole, a reducing ion such as SO.sub.2, alcohol, and iodide in an amount between 0.002 and 0.4 mol/liter. The titrant is an iodine-containing solution.

Abstract: Photometric apparatus, for counting the particulate components in blood and for determining the degree of particulate agglutination is disclosed. The apparatus comprises a body provided with an absorbent well for holding the blood bearing solution. The body is further provided with a passage to allow communication between the well and a detector which is capable of detecting the response of the particulate material to stimulating radiation. The absorptive well has the characteristic of absorbing radiation at the wavelength which characterizes the response of the particulate material to stimulating radiation. The well advantageously prevents the detector from detecting radiation that would otherwise be reflected by the well, whereby the linearity of the response of the apparatus is greatly increased. Linearity is further enhanced by assuring full crenation of the cells with a specific reagent.

Abstract: A small volume electron capture detector has a cylindrical cell 120 inside which there is provided a generally funnel-shaped insert structure 130 having a cup-shaped section and a cylindrical section. The rims of the cup-shaped section nearly touch the inner walls of the cell 120 so as to separate the active volume from the areas at the top corners of the cell 120 which are not actively swept by the carrier gas, thus reducing the tailing of chromatographic peaks.

Abstract: Method for measuring particulates in flue gas streams containing chemicals reactive with trace elements in the filters is disclosed which features pretreating the filters with chemicals comparable to those in the process stream whereby the reactions are completed prior to the measurement step, in particular, prior to establishment of the tare weight of said filter.

Abstract: The present invention relates to a novel method and apparatus which can provide continuous monitoring of the oxygen content of a gas over an indefinite period of time and at a minimal cost.In the novel apparatus of the present invention, a light source and a light sensitive detector are disposed within the atmosphere to be measured, and a polymeric film formed from a manganese tertiary phosphine polymer complex is deposited between the light source and the detector. As oxygen pressure increases or decreases a change in color intensity of the film takes place which controls passage of light from the light source to the detector. The detector in turn is suitably connected to an audio and/or visual warning device and/or a recorder which will provide the desired form of warning.

Abstract: The invention relates to a process for determining water in samples containing water. This process is characterized in that a solvatochromic compound is added to a solution or dispersion of the sample in a solvent or directly to the liquid sample, the solvatochromism band .lambda..sub.max in the UV-vis-spectrum is determined, the E.sub.T -value (molar excitation energy) of the solvatochromic compound is calculated and the water concentration is determined in accordance with the following equation:c.sub.H.sbsb.2.sub.O =C*exp(E.sub.T /E.sub.D -E.sub.T.sup.o /E.sub.D)-c* (1)in whichE.sub.T is the molar excitation energy of the solvatochromic compound,E.sub.T.sup.o is the E.sub.T -value of the pure anhydrous solvent,c* and E.sub.D are empirical parameters which may be taken from Tables or empirically determined.

Abstract: The invention relates to a process for determining the composition of binary liquid mixtures. This process is characterized in that a solvatochromic compound is added to the sample to be analyzed, the solvatochromism band .lambda..sub.max is determined in the UV-spectrum, the E.sub.T -value (molar stimulation energy) of the solvatochromic substance is calculated and the concentration of the more polar component is determined in accordance with the following equationc.sub.P =c*exp(E.sub.T /E.sub.D -E.sub.T .degree./E.sub.D)-c* (1)in whichc.sub.P represents the concentration of the more polar component, the component having the greater E.sub.T 30-value being defined as the more polar component,E.sub.T represents the molar excitation energy of the solvatochromic compound,E.sub.T .degree. represents the E.sub.T -value of the pure, more apolar component,E.sub.T 30 is the E.sub.T -value using pyridinium phenol betaine andc* and E.sub.

Abstract: There is shown a cartridge assembly which is used to analyze the coagulation of blood when subjected to an additive reagent. A base plate is divided into two sections as a right and left section by means of a longitudinal groove. Located on the right side of the groove is a plurality of first cylindrical chambers. Located on the left side of the groove is a second plurality of cylindrical chambers. The chambers on the right side of the groove have a top depression with sloping sidewalls which are adapted to receive extending tapered flanges associated with the chambers on the left side of the groove. In this manner upon folding or pivoting the cartridge about the groove, the chambers on the left and right side coact with one another. In operation the chambers on the left side of the groove receive a blood sample while the chambers on the right side of the groove receive a suitable reagent.

Abstract: In a method for determining macromolecules in polyacrylamide gels comprising the steps of forming a latent stain image by nucleating the macromolecules in the gel with a palladium tetramine salt and developing the latent stain image by treating the gel with a physical developing solution comprising dimethylamine borane and a transition metal salt, the improvement comprises contacting the developed latent stain image with a 1-phenyl-2-tetrazoline-5-thione or a salt of 1-phenyl-1H-tetrazole-5-thiol.

Abstract: Method for determining monomer conversion in the liquid phase by analyzing vapor phase above a polymerization mixture comprising measuring temperature of the vapor phase, analyzing the vapor phase with a gas chromatograph provided with a flame ionization detector to determine relative amount of a certain monomer in the vapor phase, correlating initial amount of the monomer with an intermediate amount of the monomer adjusted by applying a temperature correction, and determining monomer conversion on the basis of an essentially linear relationship of conversion in the liquid phase with relative amount of the monomer in the vapor phase.

Abstract: The invention relates to the use of a compound of the chemical formula: ##STR1## in which: R.sub.1 and R.sub.2 are the same or different and represent hydrogen, halogen, and a lower alkyl or alkoxy group containing 1 to 4 carbon atoms, a (C.sub.1 -C.sub.4)-dialkylamino group, an acetylamino group, a nitro group or an aromatic group which may be substituted or anellated;n is an integer from 1 to 4, preferably 1 or 2;m is likewise an integer from 1 to 4, preferably 1 or 2; andR.sub.

Abstract: Method for determining the onset of the fertile period of a human female comprising the step of monitoring the axillary secretions of said female during the course of her menstrual cycle to determine variations in the concentration of androstenol or dehydroepiandrosterone sulfate. A first significant increase in the concentration of either of those compounds following the cessation of menses is indicative of the onset of the fertile period. In each case, a follicular phase peak occurs which exceeds by at least twice the concentration of those compounds present at any other time during the menstrual cycle. As a result, the monitoring of these compounds may act as reliable indicators predicting the occurrence of ovulation in five to seven days, and/or indicating the onset of the fertile period at a time when appropriate contraceptive measures can still be taken to avoid pregnancy or sexual intercourse can promote fertility.

Abstract: A test means for determining the presence of an ion in an aqueous test sample is disclosed, as well as a test device incorporating the test means, a method for preparing it and a method for using it. The test means is composed of a porous carrier matrix incorporated, substantially uniformly, with a homogeneous hydrophobic composition and with a buffering substance capable of providing a pH in the range of from about 5 to 10. The homogeneous hydrophobic composition contains an ionophore capable of forming a complex with the ion, a hydrophobic substance and a reporter substance capable of interacting with the complex of ionophore and ion to produce a detectable response. In a preferred embodiment, this invention provides a colorimetric test capable of measuring serum potassium.

Abstract: An apparatus responsive to optical changes in a waveguide when the latter is contacted with an analyte capable of reacting with a specific reactant thereto attached to the surface of said guide involves, for containing the analyte, an interchangeable round bottomed cuvette temporarily held by a suitably shaped carrier in working relationship with the optical components of the apparatus, this arrangement ensuring a correct optical orientation thereof relative to said component whatever the exact positioning of the cuvette.

Abstract: A process for the continuous preparation of slides to be chemically analyzed comprises forming regularly a plurality of hollows on an advancing web material; putting a piece of film to be chemically analyzed in each of the hollows; sticking a long covering member having a plurality of apertures corresponding in their positions to the hollows on the web material onto the surface of the web material so that the apertures and the hollows on the web material are in registration; and cutting the circumference outside of each of the hollows. Also disclosed is a slide to be chemically analyzed which comprises a web material having a hollow in the central region thereof in which a film to be chemically analyzed is put, a covering member having an aperture on the surface thereof stuck to the web material; and downwardly extending flanges on a circumferential portion of the slide having heights substantially equal to that of the hollow to stabilize positioning of the slide.

Abstract: This disclosure relates to a method and reagents for determining ligands in biological fluids such as serum, plasma, spinal fluid, amnionic fluid and urine. In particular, this disclosure relates to a fluorescence polarization immunoassay procedure and to a novel class of tracer compounds employed as reagents in such procedures. The procedure disclosed combines the specificity of an immunoassay with the speed and convenience of fluorescence polarization techniques to provide a means for determining the amount of a specific ligand present in a sample.

Abstract: A gas flow cartridge in which to conduct analytical coagulation tests on a sample of fluid such as blood includes a tube-like member and a resilient flexible membrane having a slit formed therethrough to divide the tube-like member into an upper reaction chamber in which the test takes place and into a lower reagent chamber which initially contains reagent to be mixed with the sample of liquid upon which the test is to be conducted. The contents of the reagent chamber are forced through the slit in the resilient flexible membrane due to the flexing of the membrane around the slit when pressure is applied. Once the reagent is in the reaction chamber with the sample of fluid, a flow of gas is forced upward through the slit in the membrane during the analytical test.

Abstract: An article which in use is heated to an elevated utilization temperature comprises a thermochromic composition, which when heated to a transition temperature, provides a visible color change in less than about 5 seconds. The transition temperature is at least 30.degree. C. greater than the utilization temperature. To place visible indicia on the article, the article is heated to a temperature at least as great as the transistion temperature.

Abstract: A device and method are described for forming a drop of two liquids pendent each from a separate platform. Means are included for moving the platforms from a spaced-apart position to one in which the drops contact each other and coalesce, while still pendent from the platforms.

Abstract: The concentration of unspent zinc-based hydrogen sulfide scavenger in an aqueous drilling fluid is controlled by selectively extracting an unspent scavenger in a solvent, such as glacial acetic acid, measuring the concentration of dissolved zinc, for example, with an X-ray fluorescence spectrograph, and utilizing the results of the measurements to proportion the extent of changes to be made in the concentration of the scavenger.