Abstract: The invention provides methods for isolating a target molecule from a sample. In an embodiment, the method involves contacting a sample with a capture agent, the agent comprising a siderophore and a transition metal cation, under conditions wherein the agent is capable of binding a target molecule to form a target molecule-capture agent complex, wherein the target molecule is selected from the group consisting of a phosphorylated molecule, a nitrotyrosine-containing molecule and a sulfated molecule, and separating the target molecule-capture agent complex from the sample, thereby isolating the target molecule from the sample. Also provided are methods for determining the presence of a target molecule in a sample, that involve contacting a sample with a capture agent, the agent comprising a siderophore and a transition metal cation.

Abstract: The systems and methods described herein relate to the measurement of nitrate levels in a sample of gas, for example, air, exhaust, or other sources of gas. Moreover, the systems and methods described herein are capable of operating using short sample collection periods, permitting rapid data collection and finely time-resolved nitrate monitoring over a span of time. Additionally, ambient nitrate can effectively be distinguished from other airborne particles, such as sulfate and carbon.

Abstract: Elemental analysis of a sample is carried out in an oxygen atmosphere in a combustion reactor and the volume of oxygen required for analysis is determined by means of the algorithm Qo=&Dgr;(Qc)  [1] where Qo is the volume of oxygen required and Qc is the weight of the sample to be analyzed and &Dgr;=Qo1/Qc1 where Qo1 is the volume of oxygen necessary for the combustion of a predetermined quantity Qc1 of the sample to be analyzed, the volume of oxygen Qo is then fed in pulsed mode to the combustion reactor, by means of a flow detector.

Abstract: An analyzer compensates for gas flow perturbations by providing a makeup flow of carrier gas to maintain the pressure and/or flow rate of analyte and inert gas through a detector constant such that a accurate determination of a low concentration of an analyte in the presence of a high concentration of a second analyte can be accurately determined. In one embodiment, a carrier gas is introduced through a valve responsive to the detected pressure in the gas flow stream between a scrubber and a subsequent detector for maintaining the pressure constant during an analysis. In another embodiment of the invention, a flow transducer is positioned in the gas flow path between the scrubber and detector and coupled to a flow control valve coupled to introduce carrier gas as a function of detected gas flow such that the flow rate of gas into the detector is maintained constant.

Abstract: A system and method for controlling a microwave heated chemical process is disclosed. Time varying concentrations of some chemical substances within fumes in the microwave oven are monitored to detect concentration variations for which responses are known. Responses to the detected variations are initiated to control the chemical process without terminating the process. Examples of responses include varying microwave radiation energy, initiating safety systems, increased venting of the microwave oven, and so forth.

Abstract: A system and method for controlling a microwave heated chemical process is disclosed. Time varying concentrations of some chemical substances within fumes in the microwave oven are monitored to detect concentration variations for which responses are known. Responses to the detected variations are initiated to control the chemical process without terminating the process. Examples of responses include varying microwave radiation energy, initiating safety systems, increased venting of the microwave oven, and so forth.

Abstract: A method for microwave assisted chemical processes is disclosed that comprises applying sufficient microwave radiation to a temperature-monitored mixture of reagents, with at least one of the reagents being thermally responsive to electromagnetic radiation in the microwave range, and based on the monitored temperature, to maintain the added reagents at or closely about a predetermined temperature while substantially avoiding thermal dilution (or before substantial thermal dilution can occur) that otherwise would have been caused by the addition of the reagents to one another.

Abstract: A method for microwave assisted chemical processes is disclosed that comprises applying sufficient microwave radiation to a temperature-monitored mixture of reagents, with at least one of the reagents being thermally responsive to electromagnetic radiation in the microwave range, and based on the monitored temperature, to maintain the added reagents at or closely about a predetermined temperature while substantially avoiding thermal dilution (or before substantial thermal dilution can occur) that otherwise would have been caused by the addition of the reagents to one another.

Abstract: A method of monitoring compliance of a patient that has been placed on a medication maintenance program with a prescribed medication dosage by determining a normalized urine medication concentration. An unadulterated urine sample is obtained from the patient. The urine medication concentration and urine specific gravity are measured. The normalized urine medication concentration is calculated as a function of the measured medication concentration in the urine and the urine specific gravity. The calculated normalized urine medication concentration is compared with an expected medication concentration value for the patient for the maintenance program prescribed to determine any significant differences therebetween as an indication of noncompliance. Alternatively, a urinary-parameter normalized urine medication concentration is calculated as a function of the measured medication concentration in the urine, the urine specific gravity and at least one selected pharmacokinetic parameter of the medication.

Abstract: A method and apparatus for the chemiluminescent determination of NO/NO.sub.x in a sample gas is disclosed in which the NO.sub.x portion of the gas stream is catalytically converted in a preconditioned vitreous carbon bed at a relatively low temperature effective to catalytically convert NO.sub.x to NO and below 200.degree. C. The vitreous carbon is preconditioned by heating at a temperature of between 300.degree. C. and about 500.degree. C. for a sufficient period of time, on the order of two to five hours. The apparatus consists of a converter containing the preconditioned vitreous carbon in communication with a reaction cell consisting of a hollow cylindrical housing having an open end closed by an optical filter. A suitable photodetecter is disposed to detect light emitted through the optical filter. A chemiluminescent reaction between ozone and NO in the sample stream occurs in a reaction chamber defined by the interior of the housing. A reflector element may be disposed in the reaction chamber.

Abstract: This invention provides a process for determining the nitrogen content of a sample involving (a) combusting the sample in a combustion reactor in the presence of oxygen, which oxygen is introduced into the combustion reactor in pulse form; (b) reducing the resulting combustion gases by flowing them in a flow of helium or other noble carrier gas through a Cu-containing reduction reactor; (c) performing the steps of (i) making anhydrous in a water trap the reduced gases, (ii) flowing the reduced gases through a gas-chromatographic column in order to carry out a gas-chromatographic separation of N.sub.2 from CH.sub.4 possibly present within the reduced gases, and (iii) removing CO.sub.2 from the reduced gases using a CO.sub.2 trap, with the proviso that step (i) immediately precedes step (ii); and (d) analyzing the resulting gases by detecting thermal conductivity.

Abstract: A method of determining nitrogen in various nitrogenous materials, wherein the materials are combusted by being brought into contact with a solid metallic catalytic mass, in the presence of an oxygenated gas, so as to convert the nitrogen into NO. This is then determined, preferably by chemiluminescence or by optical interferometry. The method is improved by adding a halide of an alkali metal or an alkaline earth metal to the materials prior to combustion.An apparatus comprising an oven (1,2,2') charged with catalytic mass (4), which can be a wire acting as a heating element, and provided with an oxygen inlet (6). The catalytic mass is a non-oxidizable ferrous alloy or a metal of the Pt group.

Abstract: A system and method for determining the concentration of nitrate ions in a nitrate ion-containing water sample which also contains chloride ions and bicarbonate ions is disclosed. The potentially interfacing chloride ions are suppressed by reaction with a cation exchange resin in the silver form. The potentially interferring bicarbonate ions are suppressed by reaction with a cation exchange resin in the hydrogen form. The sample, after having been treated with the two resins is passed into a conductivity cell with the conductivity being directly related to the nitrate ion concentration of the sample. The device and method find advantageous application in automated systems for monitoring and controlling water treatment facilities.

Abstract: Gas samples withdrawn from within a reactor vessel (or process in general), as well as from one feed gas thereto, are passed to gas analyzers for particular components or impurities desired to be measured. The response time of the reactor analysis system employed is advantageously minimized by the elimination of dead gas space within the system and the provisions for rapid purging of the system or of individual gas analyzer feed lines. The flexibility of the system to measure both particular gas sample components and periodically present impurities using the same analytical instruments is generated by the addition of an in-line reaction system comprised of reactant addition means and/or catalyst means to individual sample lines leading to particular analytical instruments.

Abstract: A rapid, microwave-based Kjeldahl digestion method wherein microwave energy is applied to an acid/sample mixture at the beginning of, and thereafter during the digestion. After the application of microwave energy is discontinued, the digestate is diluted by pulsed addition of water, followed by continuous addition of water. Dilution in this manner prevents a sudden surge in gas evolution, and eliminates the need for an intervening cooling step, thereby reducing processing time. Also provided is a method for fat separation from a fat-containing protein sample during the digestion.

Abstract: Gas samples withdrawn from within a reactor vessel, as well as from the feed gas thereto, are passed to gas analyzers for particular components or impurities desired to be measured. The response time of the reactor analysis system employed is advantageously minimized by the elimination of dead gas space upon the closing of control valves and the provisions for rapid purging of the system or of individual gas analyzer feed lines.

Abstract: The nitrogen-selectivity of an atomic emission detection system is enhanced by use, as the reagent gas, of a single gas or a mixture of gas components containing oxygen and hydrogen in an oxygen/hydrogen molar ratio of about 1:10 to 10:1.

Abstract: An improved process for quantitatively determining nitrogen content or other elemental content in a wide variety of materials. The process avoids the use of conventional catalysts, is simpler and faster than previous techniques, and results in a very high degree of accuracy. The process involves the use of a hydrogen peroxide which is added to the digest continuously, while the digest is boiling, while refluxing with a fractionating column. The digestion process also enables quantitative determination of various elements other than nitrogen.

Abstract: An improved process for quantitatively determining nitrogen content in a wide variety of materials. The process avoids the use of conventional catalysts, is simpler and faster than previous techniques, and results in a very high degree of accuracy. The process involves the use of a reagent solution prepared by mixing hydrogen peroxide and concentrated sulfuric acid. The digestion process also enables quantitative determination of various elements other than nitrogen.

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

Abstract: The specification discloses an analyzer for determining the carbon, hydrogen, and nitrogen content of an organic material. The analyzer includes a vertically oriented, U-shaped furnace including a combustion chamber containing a crucible in which the sample is combusted into constituent gases and a reagent chamber containing a reagent through which the constituent gases must pass. A lance extends into the combustion chamber to guide the sample into the crucible and to direct oxygen onto the sample combusting in the crucible. The analyzer further includes an equilibration vessel and means for conveying the constituent gases to the vessel and past CO.sub.2 and H.sub.2 O infrared cells to monitor the products of combustion. Means are provided for conveying the equilibrated gases past the infrared cells to obtain readings relating to carbon and hydrogen content. A doser doses an aliquot of the equilibrated gas into a nitrogen measurement apparatus to obtain a reading relating to nitrogen content.

Abstract: A gas chromatographic apparatus is provided which comprises a gas chromatography column, a detector and an extended conduit between the column and the detector, the conduit providing means for flow of a gas so as to enable essentially complete elution of the gas from the column before the gas is detected by the detector. The apparatus can be adapted for use in an instrument for the elemental analysis of a sample for carbon, hydrogen, nitrogen and sulfur. The invention method includes the steps of introducing a sample in vapor form into a gas chromatography column, passing the sample through the column so as to separate at least one component of interest, passing the component of interest through a conduit to the detector so as to reach the detector after the essentially complete elution of the component of interest from the column.

Abstract: An automatic apparatus for loading and feeding crucibles to and removing crucibles from a combustion furnace in which metals are burned for analyzing them. The apparatus has a part for automatically transporting crucibles to a sample weighing position one by one, a sample weighing device at the sample weighing position, and a supply device for placing the desired quantity of metal to be analyzed into crucibles at the sample weighing position. A storage device for automatically storing crucibles containing samples therein extends from the sample weighing position, and a device takes crucibles out of the storage device one by one and a further device automatically takes the crucibles from said taking out device and introduces them into a combustion furnace and removes the crucibles from the combustion furnace. A device then automatically dumps the crucibles removed from the combustion furnace after the completion of analysis.

Abstract: An analytical method for the independent or simultaneous determination of any number of elements selected from the group consisting of nitrogen, carbon, hydrogen and sulfur or chlorine in samples, which comprises passing an oxygen gas through a reaction tube packed with an oxidation catalyst or oxidizing agent having a heating zone of from 800.degree. C. to 1100.degree. C., introducing a sample into said tube to subject it to complete combustion, uniformalizing the gas, dividing the gas into two portions, and introducing one portion in a carrier gas into a copper-reducing tube having a heating zone of from 400.degree. C. to 700.degree. C., determining the resulting nitrogen gas, carbon dioxide gas and steam or acetylene gas on a gas detector, while introducing the second portion in an oxygen gas into an absorption liquor, and determining the resulting sulfate or chlorine ion and, an apparatus useful therefor.