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: A specific binding enzyme-resistant ligand assay test material, which material comprises (a) a solid phase incorporated with one partner of a specific binding pair comprising said ligand or a binding analog thereof and a specific binding protein therefor; (b) a conjugate comprising the other partner of said specific binding pair incorporated with a substance which protects the specific binding protein of said pair from enzyme inactivation when bound with its partner; and (c) an active protein-inactivating enzyme. Also a specific binding method of assaying for an enzyme-resistant ligand in a sample, which method uses the above test material and which results in a reduction in interference caused by non-specific protein.

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: 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: 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: 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 aqueous solution of silver nitrate is effective to detect phosphorus segregates in a metallic material, particularly cast steel. Segregated phosphorus can be detected by etching a surface of steel to be tested, attaching test paper onto the steel surface, applying an aqueous solution of 0.1 to 80% by weight of silver nitrate to the paper, maintaining the paper in contact with the steel surface for a sufficient time, removing the paper from the steel surface, and subjecting the paper to fixing treatment.

Abstract: Phosphorus segregates formed in cast steel upon solidifying are detected by a novel method comprising applying a metal etching reagent, for example, lithium chloride in ethanol, to a surface area of the steel to be examined, and attaching a sheet of test paper bearing an aqueous solution of silver nitrate to said surface, thereby detecting phosphorus segregates as stains on the sheet.

Abstract: Process for the determination of carcinoembryonic antigen (CEA) in a sample of serum or plasma. The process comprises contacting a slightly acidic buffered sample of the serum or plasma with hydrophilic silica at room temperature, separating the silica from the sample and carrying out a radioimmunoassay for carcinoembryonic antigen on said sample.

Abstract: A method of fluxing an oxide sample includes placing the sample in a crucible which has a central axis and a bottom, and heating the crucible and thus the oxide sample. A motion is applied to the crucible whereby the central axis moves to describe a conical surface with an apex on the central axis and spaced from the bottom of the crucible by a distance equal to or less than the crucible height. The crucible itself is restrained against rotation about its own axis.

Abstract: Compositions and methods are provided for clarifying and partitioning aqueous lipid-containing specimens or samples such as lipemic serum and plasma. The compositions contain zwitterionic surfactant and water-immiscible organic solvent for lipids. The components of the compositions are selected such that they are compatible in vitro and, when constituted with aqueous specimens, do not interfere with biological or chemical activity of endogenous and exogenous analytes present in the respective specimens. The methods serve to partition the specimens into discrete aqueous and non-aqueous phases. The phases in turn can be individually assayed with respect to any of various analytes, for diagnostic or other purposes.

Abstract: A composition, test means (and device) and method for determining peroxidatively active substances in a test sample are disclosed. The composition, test means (and device) and method are rendered resistant to the adverse affects of ascorbate which may be present in the sample by the inclusion in the composition of a metal chelate which is polycarboxyalkylamine derivative having the formula: ##STR1## where: (a) R.sub.1 is hydrogen or straight or branched chain alkyl alcohol or alkyl carboxylic acid radicals having from 2 to 3 carbon atoms; R.sub.2, R.sub.3, R.sub.x and R.sub.y, same or different, are straight or branched chain alkyl alcohol or alkyl carboxylic acid radicals having from 2 to 3 carbon atoms; where at least two of R.sub.1, R.sub.2, R.sub.3, R.sub.x or R.sub.y are alkyl carboxylic acid radicals so defined;(b) R.sub.p and R.sub.

Abstract: Method and apparatus for analysis, by ion chromatography, of anions, in a sample solution, wherein accurate analysis of anions in the sample solution is obtained by passing carbonic acid, through a prescribed membrane, into the sample solution, thereby completely eliminating or sharply lessening the so-called water dip effect. The method and apparatus are further directed to enabling anions in the sample solution to be accurately analyzed by passing prescribed cations, through a prescribed membrane, into the sample solution, thereby depriving the sample solution of interfering anions otherwise abundantly present therein.

Abstract: The present invention provides a process for the removal of turbidities in biological fluids by the addition of surface-active agents, wherein, as surface-active agents, there are used(a) a polyethoxylated triglyceride with an HLB value of 4 to 14,(b) a secondary n-alkane sulphonate, as well as optionally(c) a further non- or anionic tenside,in aqueous, optionally buffered solution.

Abstract: The present invention provides for on-site capture of carbonaceous gas at sea, for isotopic examination to enable prediction of hydrocarbon potential of an earth formation underlying a body of water.

Abstract: A sulfur dioxide-containing analysis stream, such as formed by the oxidative pyrolysis of a sulfur-containing liquid, is passed through a trapping medium comprising metal or metal oxide, preferably nickel oxide, wherein the sulfur dioxide is retained while the remainder of the gas flows through. Thereafter, the flow of analysis gas is discontinued and the trap zone is heated to release the sulfur dioxide, which is passed in an inert carrier gas stream through a sulfur dioxide detector such as a conductivity cell. Halides in the analysis stream are removed prior to trapping by being dissolved in an aqueous liquid in a scrubbing chamber. Such chamber is regenerated by vaporizing the halide-containing aqueous solution and venting it. Also, a system of the foregoing type including two traps and a single detector whereby two samples are alternately analyzed and trapped to reduce the overall analysis time.

Abstract: The present invention provides a process for removing ascorbic acid from aqueous solutions by the addition of ascorbate oxidase, wherein catalase and hydrogen peroxide are also added to the solution.The present invention also provides an agent for the removal of ascorbic acid from aqueous solutions, based on a solid carrier material impregnated with ascorbate oxidase, wherein the carrier material also contains catalase and hydrogen peroxide and optionally also a stabilizer and/or buffer substance.

Abstract: The present invention provides for on-site capture of carbonaceous gas at sea, for isotopic examination to enable prediction of hydrocarbon potential of an earth formation underlying a body of water.

Abstract: A novel enzyme of bilirubin oxidase produced by a genus Myrothecium or genus Coprinus origin microorganism and a conventional enzyme of laccase are found, in the presence of a specific additive compound, e.g. a surface active agent, aromatic carboxylic acid, sulfa drug or protease, to oxidize both conjugated and unconjugated bilirubin in biological fluid to biliverdin without formation of hydrogen peroxide, such that in the case of conventional enzymatic methods of the quantitative determination of glucose, cholesterol, neutral fats, free fatty acids, phospholipids or uric acid all existing together with bilirubin in biological fluid, the usual interference with such determination, as otherwise caused by bilirubin coexisting in such fluid, can be prevented by adding such a bilirubin oxidase or laccase together with such a specific additive compound to the determinative reaction system.

Abstract: A novel, inexpensive, highly sensitive and quantitative assay for measuring protein in solution based on the capacity of protein to bind silver is described. In this procedure, protein samples are first treated with glutaraldehyde and then exposed to ammoniacal silver. After a specified time, the reaction is terminated by the addition of sodium thiosulfate and the optical density measured at 420 nm. The useful range of the assay for the majority of standard proteins tested lies between 15 and 2000 ng. This represents a 100-fold increase in sensitivity over the Coomassie Brilliant Blue dye binding procedure. There is little or no interference from carbohydrates, non-ionic detergents or ethanol. Pretreatment of protein samples with Bio-Gel P-2 to remove salts, thiol agents, EDTA and SDS, makes this procedure compatible with most commonly used buffers.

Abstract: A multizone analytical element for the determination of an analyte in an aqueous liquid comprises a registration zone and a porous spreading zone to receive and transport the aqueous liquid. The spreading zone contains a nonpolymeric quaternary ammonium compound represented by either of the structures: ##STR1## wherein represents a single or double bond; R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are independently alkyl; aryl; cycloalkyl; or alkaryl; provided that R.sub.1, R.sub.2, R.sub.3 and R.sub.4 together comprise at least 12 carbon atoms; or R.sub.1 and R.sub.2 taken together with the nitrogen atom, form a quaternary 5- to 16-membered heterocyclic ring; or R.sub.1, R.sub.2 and R.sub.3 taken together with the nitrogen atom, form a quaternary 5- to 16-membered heterocyclic ring; and X.sup.- is a monovalent anion.

Abstract: Method and apparatus for analysis, by ion chromatography, of anions, in a sample solution, wherein accurate analysis of anions in the sample solution is obtained by passing carbonic acid, through a prescribed membrane, into the sample solution, thereby completely eliminating or sharply lessening the so-called water dip effect. The method and apparatus are further directed to enabling anions in the sample solution to be accurately analyzed by passing prescribed cations, through a prescribed membrane, into the sample solution, thereby depriving the sample solution of interfering anions otherwise abundantly present therein.

Abstract: A method for determining the coating weight and composition of a zinc phosphate coating on a ferrous metal surface comprises stripping the coating from a known area using an aqueous solution of sodium hydroxide and triethanolamine, thereafter measuring the iron and phosphate contents by colorimetric analysis of the stripping solution and then determining the coating weight and composition based on such measurements.

Abstract: An improved colorimetric assay method and reagent composition for the quantitative determination of creatinine in biological fluid specimens in the presence of protein, in which the specimen is reacted directly with an alkaline picrate reagent composition which contains an iron chelator, preferably ethylenediaminetetraacetic acid, thereby significantly suppressing interference from bilirubin and improving reagent stability.

Abstract: A method and catalyst for the determination of nitrate in water which has been obtained by reduction of a solution of a salt of a transition metal or group VIII of the periodic system and a transition metal salt of the copper group in the presence of an acid. The nitrate determination is effected by determining the nitrate extinction of a sample of water as compared with a blank sample in the UV region at 210 nm, a part of the sample of water whose nitrate has been reduced in the presence of hydrogen with the use of the catalyst of the invention being employed as blank sample.

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

Abstract: A quantitative method useful for field monitoring low concentrations of water soluble, polyacrylic acids in aqueous systems containing polyacrylic acids and other soluble ionic materials, such as ionic salts and phosphonates, is provided. The method involves adjusting the pH of the aqueous system to suppress the ionization of the polyacrylic acids followed by selective adsorption and concentration of the polyacrylic acids on a suitable adsorbent. Concentrated polyacrylic acids are then desorbed from the adsorbent and the concentration of the polyacrylic acids in the aqueous system is determined by conventional techniques.

Abstract: An improved apparatus for electrochemically analyzing a sample in solution is described. The apparatus comprises an electrochemical detector comprising a plurality of electrochemically isolated flow cells arranged in series so as to define at least one flow path. Each of the electrochemical flow cells in turn comprises at least one working electrode, at least one reference electrode, and at least one counter electrode. Electrical potentials are applied to the various working electrodes so that the sample solution is cyclically subjected to oxidation and reduction conditions whereby selected substances contained in the sample solution may be electrically screaned or modified prior to detection and measurement on a downstream sensing electrode.

Abstract: An overcoat composition for use in ion-selective electrodes comprises: (a) a discontinuous liquid phase comprising an oleophilic solvent dispersed within a continuous phase comprising a hydrophilic binder; (b) a complexing agent useful for extracting oleophilic anions; (c) a buffer which provides a pH in the range of from about 7.5 to about 9.5 under conditions of use; and (d) a nucleating agent. This overcoat composition is particularly useful in ion-selective electrodes for determination of CO.sub.2.

Abstract: A method for eliminating turbidity in a biological fluid by combining said fluid with a surfactant and an enzyme is disclosed as well as a diagnostic reagent formulation for that purpose.

Abstract: Bacterial endotoxin in an assay sample is determined by an amoebocyte lysate component of horseshoe crab in the presence or absence of a substrate for endotoxin determination by using an assay sample in the liquid state obtained by treating said assay sample with an endotoxin-free acid having a pKa.sup.25.degree. C. value of not more than 3 at a pH of not more than 3; and a kit therefor, a receptacle containing (a) an endotoxin-free acid having a pKa.sup.25.degree. C. value of not more than 3 e.g. perchloric acid, trichloroacetic acid, nitric acid, for treating the assay sample and a receptacle containing (b) an amoebocyte lysate component or horseshoe crab. The acid treatment of the assay sample results in improved accuracy, reliability and reproducibility of the bacterial endotoxin determination.

Abstract: A method for diagnosing and monitoring cancer, which comprises precipitating certain components from blood serum by addition of a benzenesulfonic acid or a benzylsulfonic acid, determining the sialic acid content of the supernatant, and comparing its sialic acid content with the sialic acid content of sera from healthy subjects after identical treatment. The determination of the sialic acid by the thiobarbituric acid colorimetric method is improved by addition of N,N-dimethylacetamide during development of the chromophore.

Abstract: The present invention provides a process for the direct turbidimetric determination of .beta.-lipoproteins (LDL) in body fluids by precipitation with polyanions and divalent cations, wherein the precipitation is carried out in the presence of a complex former at a pH value of from 7 to 9.The present invention also provides a reagent for the direct turbidimetric determination of .beta.-lipoproteins (LDL) in body fluids, comprising a polyanion, a salt of a divalent metal, a complex former and a substance buffering at pH 7 to 9.

Abstract: A composition comprising phenol red, phenol, and deionized water and preferably sodium hydroxide and citric acid and a method for measuring pH wherein such composition is added to a water sample.

Abstract: A substantially solids-free sample of an oil having substantially the same hydrocarbon distribution as a heavy oil contained in a subterranean reservoir is prepared by vacuum-topping a field sample of the oil or oil-containing material while cold-trapping volatiles, diluting the topped oil with a volatile oil solvent, mechanically separating the solution from entrained solids, vacuum-distilling the solvent from the dissolved oil and recombining the oil and the cold-trapped volatiles.

Abstract: A method of analyzing fuel oil for a catalyst component which comprises dissolving a sample amount of the oil in an organic solvent, filtering the oil solution, bringing the filtration residue into contact with hydrofluoric acid to dissolve the silicon contained in the residue into the acid, and then subjecting the silicon solution to colorimetric analysis for the determination of the Si ion content.

Abstract: A method for the separation of theophylline and caffeine contained in body fluids is provided. A macroreticular styrene-divinylbenzene copolymer resin activated by a protic solvent is utilized. The body fluid is eluted with water in an isocratic manner to afford a theophylline sample uncontaminated with caffeine. Such samples are useful in immunoassay procedures for the measurement of theophylline.

Abstract: An improved assay method and reagent composition for the determination of magnesium in a fluid sample by reaction with an alkaline buffered solution of calmagite, in which caffeine and preferably also thiourea have been included, thereby achieving parity between protein-free and protein-containing samples while eliminating the need for cyanide.

Abstract: Vitamin B.sub.12 (cobalamin) and/or folate (folic acid) assay techniques can be simplified, by eliminating the step of heating or boiling the to-be-tested sample prior to its assay. This is accomplished by utilizing compositions and procedures:(1) which substantially completely liberate all vitamin B.sub.12 and/or folate from endogenous binding protein without heating or boiling;(2) which substantially completely destroy all endogenous binding protein which is present in the to-be-assayed sample, and which may bind natural and radioactive vitamin B.sub.12 or folate both due to its liberation from vitamin B.sub.12 or folate in the original sample or due to its unbound presence in the original sample;(3) which substantially completely inhibit or block any undestroyed endogenous binding protein; and(4) which substantially completely inhibit or destroy any intrinsic factor-blocking antibodies which may be present in the to-be-assayed sample.

Abstract: The degree of wear metal contamination in an oil is determined by treating a sample of the oil with a mixture of HF/HCl/nitric acid, diluting the oil/acid mixture with a solvent mixture consisting of a nonionic surfactant and a diluent, and spectrometrically analyzing the resulting diluted mixture. Severe wear in an oil wetted apparatus may be detected by directly analyzing spectrometrically a sample of the oil and comparing the results of such analysis with the results obtained according to the acid dissolution method described above.

Abstract: An aqueous reagent for determining inorganic phosphate in a protein-containing liquid biological sample comprises a molybdate salt, an acid capable of reacting with the molybdate salt to form molybdic acid for complexation with phosphate to form phosphomolybdate complexes, a ferric salt in an amount sufficient to inhibit turbidity in the sample, and a nonionic surfactant reagent in an amount sufficient to further inhibit turbidity in the sample, the molybdate salt and the acid being present in amounts sufficient to form an amount of molybdic acid sufficient to produce a detectible color change when complexed with phosphate in the sample.

Abstract: A solid support "dipstick" immunoassay impregnated with sodium metaperiodate (NaIO.sub.4) is described wherein ascorbate interference with an assay having a peroxidase signal producing system is reduced or eliminated.

Abstract: The present invention provides for on-site capture of carbonaceous gas at sea, for isotopic examination to enable prediction of hydrocarbon potential of an earth formation underlying a body of water.

Abstract: A consistent, stable serum having good optical qualities and improved filterability suitable for control and calibration uses is disclosed as well as its method of preparation.

Abstract: A method for detecting the presence of nitrite ions in fluids by pretreat nitrite containing fluids to enhance the detectability with nitrite detecting reagents of the nitrite ions therein, which pretreatment step comprises passing the nitrite containing fluids through activated charcoal prior to combination with a nitrite detection reagent.Also a test kit for carrying out the above method.

Abstract: A technique of determination of nitrate-nitrite content of a test sample, without also determining additional nitrogen content. The technique is highly selective and sensitive, to the parts per billion level. The nitrate-nitrite content of a sample is reduced to nitric oxide which is determined via its chemiluminescence reaction with ozone. Nitrite is selectively reduced under mild conditions and the total nitrate-nitrite content is determined by stronger reduction conditions. Specific reducing agents to be used in combination with the chemiluminescence reaction are also provided.

Abstract: An improved reagent and method for assay of total bilirubin in biological fluids utilizes diazo sulfanilic acid to convert bilirubin to azobilirubin which is then quantitatively measured. The improved reagent and method include the solvent accelerator tetramethylene sulfone. The use of tetramethylene sulfone as also allows the use of nonionic surfactants, obviating the need for serum blank correction in highly lipemic serum. Furthermore, the use of tetramethylene sulfone and nonionic surfactants renders the reagent mixture less viscous facilitating automated analysis.

Abstract: An improved process for determining glycosylated hemoglobin wherein the contribution of unstable glucose-aldimine-hemoglobin compounds to the HbA.sub.1 value is substantially eliminated by reacting the hemolysate with a primary amine and a hydrazine compound and thereafter subjecting the hemolysate to chromatography. The process enables reliable evaluation of the HbA.sub.1 value as a long-term parameter in diabetic metabolism control.

Abstract: A method for determining the concentration of carbonate salts in solutions containing other inorganic salts. The method includes converting the carbonate salts to carbon dioxide by acidifying the sample, sweeping the acidified solution with an inert gas to strip the carbon dioxide from the solution and contacting an ion-selective gas-sensing electrode with the gas stream. The electrode includes a buffered solution which changes in pH depending on the concentration of carbon dioxide in the gas stream thereby providing a measure of the carbonate salt concentration in the sample.

Abstract: A method and apparatus for the preparation of a liquid sample for the quantitative determination of boron by flame photometry. The sample is combined in a vessel with sulfuric acid, and an excess of methanol is added thereto. The methanol reacts with any boron present in the sample to form trimethyl borate which is volatilized by the heat of reaction between the excess methanol and sulfuric acid. The volatilized trimethyl borate is withdrawn from the vessel by either a partial vacuum or a positive pressure and is rapidly transferred to a standard flame photometer. The method is free of interference from typical boron concomitants.