Abstract: Sample water is supplied to an oxidative decomposer, heated to 90.degree. C. under presence of a photooxidation catalyst, and irradiated with ultraviolet radiation by a low pressure mercury lamp while being supplied with air, to cause photooxidative decomposition reaction. After the reaction, nitric acid ions are measured with an absorption photometer at a wavelength of 220 nm. Then, a color developer is added to the sample water, and the colored solution is employed for measurement of phosphoric ions with the absorption photometer at a wavelength of 880 nm.

Abstract: A kit for detecting nitroaromatic, organic nitrate, nitramine, inorganic nitrate, and chlorate and bromate explosives is characterized by the fact that for the detection of an inorganic nitrate, a reagent is used which comprises zinc powder suspended in a liquid comprising at least one water-miscible organic solvent, while for the detection of chlorates or bromates, a reagent is used which comprises an aniline salt in a homogeneous strongly acidic solution including at least one water-miscible organic solvent.

Abstract: An apparatus and method for the sensitive detection of atmospheric and/or surface absorbed nitrocompounds has been developed. The apparatus and method may be employed to detect the presence or absence of propellants, explosives, and nitropollutants. The unique feature herein is that the apparatus and method employ one laser operating at or near 226 nm. The laser photofragments the target molecule and facilitates the detection of the characteristic NO fragment, by resonance-enhanced multiphoton ionization (REMPI) and/or laser-induced-fluorescence (LIF) via its A.sup.2 .SIGMA..sup.+ -X.sup.2 II.sub.i transitions. The analytical utility of this apparatus and method has been demonstrated on numerous compounds, such as, DMNA, nitromethane, nitro-benzene, TNT, and RDX. With the present system, a limit of detection of 8 and 24 ppb is obtained for RDX and TNT, respectively, using only 100 micro-Joules per pulse of laser energy.

Abstract: The present invention relates to a method and a device for the detection of vessel dilatation components. The invention particularly relates to the detection of explosives, such as trinitrotoluene (TNT) and nitroglycerin. A biological detector is used, and precontracted blood vessels or parts thereof function as sensor elements.

Abstract: A method for analyzing total bound nitrogen in a sample and providing an output data of total bound nitrogen and constituent compounds (nitrate and nitrite) is disclosed. The total nitrogen bound method provides a discrete sample through a furnace in the presence of continuous flow of water as carrier as well as oxygen carrier gas, resulting in the oxidation of the nitrogen compounds to nitric oxide. The nitrate method involves a discrete sample with water as a carrier provided to a sparge tank. The nitrite is catalytically reduced to nitric oxide in the presence of tartaric acid and ascorbic acid. The nitrate method involves a first conversion to change the nitrate to a nitrite. The first conversion occurs in the presence of a copper-cadmium catalyst causing the formation of the NO.sub.2. The nitrile is subsequently converted into NO. The nitric oxide produced in each of the three methods is measured in a chemiluminescent nitrogen detector.

Abstract: In a color reaction method for detecting particular classes of explosives, a sample from a suspect source is subjected serially to the indicated reagents in the liquid phase, the reagents after the first being applied only if no color reaction has been obtained in the preceding test. The second and third reagents only are applied in presence of the preceding reagent(s). The first reagent is an alkaline solution of a diazotizable aminoaromatic azo-dye precursor, which detects nitroaromatic explosives. The second reagent is a strongly acidic reagent containing a nitrate to nitrite ion reducing agent and a diazo-coupler, which detects organic nitrates and nitramines. The third reagent is zinc powder suspended in a liquid, which detects inorganic nitrates. The fourth reagent is an aniline salt in a homogeneous strongly acidic solution including a water-miscible organic solvent, which detects chlorates and bromates. The invention includes also a test kit for use in the method.

Abstract: The invention relates to a procedure and agent for the colorimetric determination of nitrate ions in aqueous solutions by mixing the sample which is to be investigated with resorcinol and a mixture of sulfuric acid and phosphoric acid, characterized in that at least 2 g/l, preferably about 10 to 30 g/l chloride ions are also added.

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: A very rapid, sensitive method if provided for determination of the potential mutagenicity and/or carcinogenicity of certain petroleum oils by nitration of the oil and comparison of the light absorbance of its nitrated material with that obtained from one or more oils of known mutagenicity and/or carcinogenicity.

Abstract: Method for monitoring changes in contaminant concentration levels between a feedwater inlet and a steam outlet in a steam generating system and system for detecting sources of contaminants in a steam generating system. The method includes a reliable means for detecting organic contaminants, chlorides, sulfides and nitrides. The invention also includes a method for determining whether the organic compounds are chlorinated, sulfinated or nitrogenated. The method is based on monitoring of ion concentration levels and cation exchanged conductivities in samples of feedwater and steam.

Abstract: A microbiological culture test process for detecting the presence of nitrate-reducing microorganisms in an inoculum sample, which comprises(a) culturing a microorganism to be tested in the presence of adequately nitrite-free nitrate, for a period sufficient to allow reduction of nitrate by any microorganism (if present) that has the capacity to reduce nitrate to nitrite, (e.g. 1-6 hours);(b) exposing the culture medium after culture to (diazotizing) acid conditions in the presence of an amino-containing fluorophor thereby to cause diazotization of the fluorophor to the extent of any nitrite present in the medium to form a diazonium derivative (or further reaction product thereof) which is substantially less fluorescent (or fluoresces at a substantially different wavelength) than said amino-containing fluorophor, and(c) assessing the fluorescence of the culture medium as treated by step (b), thereby to show a reduction in fluorescence in the presence of a nitrate-reducing microorganism.

Abstract: The invention provides a multi-reagent test kit for the presumptive identification of traces of explosives and/or discriminating between "innocent" material and explosive containing a first reagent comprising about 2.5 to 20% V/V of a tetra alkyl ammonium or phosphonium hydroxide in a solvent comprising at least 60% V/V dimethylsulfoxide and about 0 to 30% V/V methanol or water and a second reagent comprising a diazotization compound and a coupling compound of a Griess reagent pair.

Abstract: A method for the colorimetric determination of nitrate ions comprises mixing the sample which is to be investigated with concentrated sulfuric acid and a color-generating compound of the formula ##STR1## wherein R is H, one equivalent of a cation, or C.sub.1-6 alkyl. A reagent and kit for colorimetric nitrate determination are also described.

Abstract: A composition for assaying nitrites comprising a diazotizable amine, an acid component and a coupling component, wherein the coupling component is a compound of the following formula I: ##STR1## wherein R represents a hydrogen atom or a straight-chain alkyl group having 1 to 6 carbon atoms, such as a methyl, ethyl, n-propyl, n-butyl, n-pentyl or n-hexyl group and n represents an integer of 1 to 6, with the proviso that the sulfoalkyl group may be substituted with at least 1 hydroxyl group,or a water-soluble salt thereof as well as test devices carrying the composition. This composition is far more sensitive than conventional compositions for assaying nitrites. With this composition, for example, a trace amount of as small as 0.02 mg/100 ml of a nitrite to be detected in urine in the diagnosis of a bacterial infection such as urinary tract infection can be detected surely.

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: A method and a device for the detection of trinitrotoluene (TNT) in efflu water from the purification apparatus of ammunition plants is described. The tube detector utilizes a basic oxide section to convert the TNT to its Meisenheimer anions, followed by an alkyl quaternary ammonium chloride ion-exchange resin which collects the colored anions. The length of the resultant stain is proportional to the concentration of TNT in the water.

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 method for the colorimetric determination of nitrate ions comprises mixing the sample to be investigated with concentrated sulfuric acid and adding a reagent which initiates coloration, the reagent being a compound of the general formula RO--C.sub.6 H.sub.4 --C.sub.6 H.sub.4 --OR, wherein R is H or substituted or unsubstituted C.sub.1-6 alkyl. A reagent and kit for colorimetric nitrate determination are also provided.

Abstract: A method for checking noise of a spectrometer or spectrophotometer. The method is of the type comprising measuring absorbance (A) or percent transmittance (%T) of a solution over a period of time. The method is characterized in that the solution comprises from about 0.040 to about 0.090 M nitrite, the nitrite being present as a nitrite ionized constituent.

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: A method and apparatus for the colorimetric testing of non-opaque fluids that comprises compact test kit apparatus made from readily available plastic components, and sets of such test kits made even more compact by a combination of chemistries for certain tests that simplifies and improves the accuracy of those tests while reducing the number of test kits required in a set. The colorimeter component of each test kit provides non-opaque colored plastic windows made from readily available commercial materials that are accurately color controlled. The colorimeter also makes automatic correction of the color windows to compensate for any initial coloration in the fluid being tested. The colorimeter also serves as the container for one complete kit and allows a set of kits to hang from closely spaced hooks to conserve space and make them exceptionally convenient to use.