Abstract: The present invention provides a general assay methodology suitable for the detection of organic analytes which are neither aldehydes nor ketones and for inorganic substances. The methodology utilizes prepared sensitized films of derivatizing agents and specific developer solutions for the selective and controlled formation of light scattering crystals whose presence serves as a qualitative and/or quantitative measure of the individual analyte of interest in the sample.

Abstract: Method for determining levels of sulfhydryl amino acids, particularly total homocysteine levels in samples of body tissue from warm-blooded animals, methods of detecting cobalamin and folic acid deficiency using an assay for total homocysteine levels, and methods for distinguishing cobalamin from folic acid deficiency using an assay for total homocysteine levels in conjunction with an assay for methylmalonic acid.

Abstract: Indicators for the detection of thio groups are disclosed together with processes for the preparation of such indicators.

Abstract: An organosulfur compound is detected and/or quantified, optionally in admixture with one or more other compounds, by reacting the organosulfur compound with gaseous fluorine at sub-atmospheric pressure and observing the chemiluminescence which develops. Detections at ultra-trace levels are achieved. A special detector cell is provided in which the reaction is performed.

Abstract: A method and apparatus are described for quantitatively determining the different forms of sulphur present in a solid matrix, e.g. coal. The novel method comprises intimately mixing finely divided coal with a finely divided solid diluent material, e.g. silica, which is inert to sulphur under reaction conditions. This mixed sample is then burned within a confined combustion zone at a predetermined elevated temperature and the combustion gases from the combustion chamber are continuously removed. These gases are passed through an infrared analyzer which continuously monitors the intensity of the infrared spectra for sulphur oxycompounds in the combustion gases. The infrared intensity is measured as a function of evolution time of sulphur oxycompound from the sample to obtain peaks in an infrared intensity-time pattern indicative of different forms of sulphur.

Abstract: A method of preparing a sulfonamide-food color additive for detecting the presence of a compound such as a sulfonamide in animal feeds and pharmaceutical preparations for human or veterinary use involves admixing a minor amount of an approved food color additive with the compound in the presence of water and drying the resulting mixture to the desired form so as to incorporate the food color additive into the water of crystallization or other molecular structure of the compound. Upon being wetted, the resulting compound-food color additive produces a readily detectable color indicative of the presence of the compound. The method is particularly useful for detecting unacceptable levels of sulfonamides in animal feeds.

Abstract: The concentration of unspent zinc-based hydrogen sulfide scavenger in an aqueous drilling fluid is controlled by selectively extracting the 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.

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

Abstract: The invention provides a method and apparatus for measuring the sodium sulfide content of liquid industrial process streams. According to this method, a sample of the liquid is passed through a heated filter to remove solids and reduce viscosity and a portion of the sample is then mixed with carbon dioxide to generate hydrogen sulfide gas. The hydrogen sulfide gas is separated from the reacted liquid sample, and a portion of the gas is mixed with dilution air and then analyzed quantitively for hydrogen sulfide.

Abstract: A stain for detecting molecules having amine or thiol groups, comprising halogenated maleimides and derivatives thereof, such as halogenated maleicdiamides. Upon binding to nitrogen- or sulfur-containing molecules, such as proteins, the halogenated stains undergo a chemical transformation which causes them to fluoresce. By applying the stain to a substrate suspected of containing amine or thiol groups and applying an ultraviolet light source thereto, any fluorescence, indicative of the presence of amines or thiols, can be readily detected.

Abstract: A process is described for separating and identifying organic sulphur compounds in petroleum distillates which comprises subjecting an aromatic-containing fraction to chromatography in a dual packed silica gel-alumina column employing pentane-ethyl acetate as a solvent to obtain a sulphur-containing eluate and analyzing the sulphur-containing eluate by gas chromatography and mass spectrometry. The aromatic-containing fraction is usually a naphtha fraction or a light gas oil fraction, with the gas oil fraction being subjected to chromatography on a silica gel column to obtain an aromatic fraction which is then subjected to the chromatography in the above silica gel-alumina column.

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.

Abstract: A method of chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction that generates chemiluminescent light and a specifically designed chemiluminescence detection cell for the reaction.

Abstract: A method for the simultaneous detection, separation and analysis by reverse hase HPLC of sulfur mustard type compounds and their major hydrolysis and oxidation by-products utilizes a novel precolumn enhancement derivatization procedure. The method involves the reaction of these nonchromophoric sulfides with N-halogeno-N-metal arylsulfonamidates on a microscale to produce UV or visible absorbing or fluorescing arylsulfonylsulfilimine compounds. These arylsulfonylsulfilimine derivatives can then be readily separated on a low polarity C-18 column by reverse phase HPLC. The method permits quantitation of these sulfides by UV detector response in quantities as small as 20 nanograms.

Abstract: A method of chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction and a specifically designed chemiluminescence detection cell for the reaction.

Abstract: An analyzer for natural gas to determine the existence of and concentration of wanted and unwanted sulfur compounds and odorizing agents.

Abstract: The geochemical oil prospecting method is disclosed in which a crude oil sample is analyzed for the presence of distinctive patterns of aromatic sulfur compounds which are indicative of the petroleum source rock type. Using relative proportions of benzothiophenes, dibenzothiophene, isomeric methyl dibenzothiophenes, dimethyl- and trimethydibenzothiophenes a crude oil can be identified as having a carbonate or siliciclastic source. The information obtained can be used in combination with geological and seismic studies to determine potential oil locations.

Abstract: Novel 4,4'-dithiodianil compounds are prepared by reacting 4,4'-dithiodianiline with an aromatic or pyridine aldehyde, such as 4-nitrobenzaldehyde. The novel dithiodianil compounds can be employed for detecting thiol compounds. They react with thiols to yield reaction products which possess a different color from the novel dithiodianil compound itself. The color change obtained in this manner with the novel compounds in many cases is stronger than that obtained with Ellman's reagent frequently employed for detecting thiols.

Abstract: Vapor permeable microcapsules filled with volatile perfluoroalkyl pentafluorosulfide and used to tag articles for the detection thereof.

Abstract: A method for determining the concentration of a brine tolerant sulfonate surfactant in a complex mixture containing, in addition to said brine tolerant sulfonate surfactant, lignosulfonates, crude oil, salts, and water and, optionally, petroleum sulfonates and alcohols, that comprises incorporating into the brine tolerant sulfonate surfactant molecule a small amount of deuterium prior to addition to the complex mixture and determining the concentration of the brine tolerant sulfonate surfactant by measuring its infrared absorption at 2150 cm.sup.-1.