Method of express detection of explosives

FIELD: measurement equipment.

SUBSTANCE: invention relates to methods of indicator detection of trace amounts of explosives and components of explosives on the basis of three groups of compound classes: nitroaromatic compounds; nitramines and nitroesters; ion nitrates. The method of express detection of explosives on the basis of a set of chemical indicators for three groups of classes of nitrogen-containing compounds includes using a reactive indicator material with reagents, previously applied in dosed quantity onto a carrier, besides, the reactive indicator material is a carrier with immobilised azocomponent of Griess reagent, which is in solid chemically modified protected form with covalently bound amides.

EFFECT: increased sensitivity and reliability, as well as faster detection.

4 cl, 4 ex, 1 tbl

 

The present invention relates to the field of research and analysis of non-biological materials using chemical methods, in particular to improved methods indicator rapid detection of high explosives) by detecting the presence of them trace quantities for preliminary classification of substances for the main classes of nitrogen-containing EXPLOSIVES, specifically to classes of compounds nitroaromatics, nitramines are, of preparing nitric esters and nitrate ion.

Due to low cost, simplicity and reliability of chemical rapid tests based on qualitative color reactions on compounds some chemical classes, exhibiting explosive properties, widely used throughout the world. Searching for ways to improve chemicals rapid detection of EXPLOSIVES has been ongoing for decades. This is confirmed by establishing the existing level of technology in this area published by the offers of various methods, compositions and devices, some of which are implemented and offered on the market.

Improved systems rapid tests is not limited to expanding the range of detectable classes of substances that are dictated by emerging new threats. Develop and already accepted technical approaches identify trace quantities �traditional organic nitrogen-containing EXPLOSIVES three groups of classes: I - vapors of nitroaromatic compounds; II - and nitramines are preparing nitric esters (in a single group); III - nitrate ion. Some representatives of these compounds produced by the industry or are their stocks. To those include TNT, RDX, HMX, PETN, nitroglycerin, black powder (potassium nitrate), ammonium nitrate and other compounds. Main directions of improvement of these methods are included in the art and are to increase sensitivity, selectivity and speed of detection, ensuring safety and convenience when working with the rapid tests, the improvement of operational performance in terms of resistance of systems to external influences during storage and application.

In the overwhelming majority of implemented and required in practice methods and kits for the rapid detection of nitrogen-containing EXPLOSIVES, since the 70-ies of XX century, used the same type of reaction in various modifications. For colorimetric determination of EXPLOSIVES, a class of aromatic policetraining, for example, uses a long-known nucleophilic reaction - their interaction with strong bases (hydroxides of alkali metals, Quaternary organic ammonium bases). This reaction with the formation of intensely colored complexes is vysokochuvstvitel�Oh and can be performed in various modifications (reaction Yanovsky, Zimmerman).

In [Patent RF 2369444, Publ. 21.03.2008, IPC B05B 17/00, G01N 33/22] patented aerosol device for rapid detection of explosives vapors of nitroaromatic number, distinctive features of which is the composition of the material of the bottle, pump sprayer and its parts. As an indicator of the composition of the proposed formulation, which, along with water-alcohol solution of the hydroxide of Quaternary alkylamine contains glycerin.

Proposed and less popular in the practice of the Express analysis of EXPLOSIVES methods such as [RF Patent 2336523, Publ. 04.07.2007, IPC: G01N 31/22, G01N 21/78, USSR Patent No. 930113 Publ. 23.05.1982, IPC: G01N 31/08], based on the formation under the influence of UV radiation dyed products of the interaction of nitro compounds and other nitrogen-containing substances with the ORGANOMETALLIC complex - cymantrene ().

The General scheme of the rapid detection of nitrogen-containing EXPLOSIVES involves the use of alkaline reagents, not only as nucleophilic agents for substances polyaromatics row, forming with them intensely colored compounds, but also the environment for the alkaline hydrolysis of nitramines are and preparing nitric esters. The resulting hydrolytic decomposition of nitrite ion has sufficient reactivity and reliably determined by using p�slichnih color reactions. A possible option may be the oxidation of the aromatic amine in a strongly acidic environment [Application US 20120003746 Publ. 05.01.2012, IPC: G01N 33/22, C07D 279/20], but more often the determining is performed using Griess reagent in various modifications - derivatives solutions 1 - naphthylamine (azocompound) and sulfanilamide acid or its derivatives in an acidic environment, similar as described in the present invention the kits and methods involved [Patent EP 0264252 A2, Publ. 20.04.1988, IPC G01N 31/22; U.S. Patent 5480612, Publ. 12.08.1993, IPC G01N 37/00; U.S. Patent 4788039, Publ. 29.11.1988, IPC G01N 31/22, G01N 33/00; Application US 20070202009 Publ. 05.01.2012, IPC: G01N 33/22, C07D 279/20].

Determination of nitrate ions described in [U.S. Patent 4690902, Publ. 01.09.1987, IPC: G01N 31/22; Zhang J.-Z., C. Fischer J. A simplified rewcorcinol method for direct spectrophotometric determination of nitrate in seawater // Marine Chemistry. - 2006. - V. 99 - P. 220-226.] involves the use as a tracer reagent of dioxybenzone in concentrated sulphuric acid. The technique was not developed in the Express analysis of EXPLOSIVES. In the implemented methods determination of nitrate involves advanced soft recoveryNO3in the acidic environment of zinc or its modified compounds such as, for example, in [Patent USSR 1638619 A1, Publ. 30.03.1991, IPC: G01N 31/22] to more activeN O2ion. The definition of the resulting ionNO2spend also using Griess reagent.

Modification of the method of determining nitrate in the proposed method [RF Patent №2206889, Publ. 20.06.2003, IPC: G01N 31/00, G01N 21/00] suggests to further increase the sensitivity as azocompound to use the derived naphthylamine without a primary aliphatic amino groups that can react with the nitrite ion in acidic medium without the formation of dye. For practical implementation of the proposed use of N,N-diethyl-N'-naphthylethylenediamine, is not given its resistance to oxidation during storage.

Apply a consistent scheme of research of the object or the sampler moved with the analyte for the presence of BB includes processing it with an alkaline solution, the application of Griess reagent and the addition of zinc dust is used in all similar to the present invention methods and presented on the chemical market rapid tests for the phased identification of compounds from the series of substituted polymicrobial, nitramines are, of preparing nitric esters and nitrate ion. The stage of detection of vapors of nitroaromatic compounds, preparing nitric esters and nitramino� involves the use of various kits and methods implementing them, liquid indicator reagents in a two-component ("anti-burst") or three-component ("Search-XT", "Virage") version. For the determination of nitrate ion in certain kits, you enter the final stage of processing samples zinc dust. Components of Griess reagent may be introduced into a solution of the base and/or in one or two acid solution.

It is known that a decrease in the activity of the solutions components used in various modifications of Griess reagent, are especially prone to oxidation azocompounds, is observed under prolonged storage and after short-term exposure to these external factors, such as intense radiation (light), fever. Set the expiration dates of reagents for detecting EXPLOSIVES, utilizing variants of Griess reagent, do not exceed 2 years, and in most cases be 1 year. To increase the stability of reagents used various techniques, in particular aimed at reducing the rate of oxidation.

For example, in U.S. patent 5480612 proposed to be added to the acidic solution of N-(1-naphthyl)ethylene diamine antioxidants (hydrazine salt, a thiosulfate). Such techniques help to increase the resistance of solutions of readily oxidizable reactants, but the task of safeguarding was not fundamentally solve.

HC�the increased stability azocompound can be achieved through the protection in aromatic amino compound, which slows down its oxidation. So the derivatives of naphthylamine less susceptible to oxidation in the form of salts due to partial deactivation. In most analogues azocompound is placed in the acidic solution, which provides greater stability of reagents.

Storage azocompound separately, in dry form, can reduce the oxidative processes and to exclude the effect of environment and other components of the solution, including dissolved oxygen. Israeli experts (patents EP 0264252, USA 4788039), propose to apply separately placed ("long-lived") components of the Griess reagent. Stored in dry form azocompound, in the form of hydrochloride, is applied before application of the aqueous solution on a filter paper and dried. But long-term storage is obtained in this manner indicator paper does not stand up - the surface gradually changes color, loses activity occurs acid the destruction of the fiber carrier under the action of acid salts and products of its hydrolysis.

A very effective method of increasing the reliability of the method is the separation of components of a system of indicators in a sealed package. However, some technical solutions allow to use for the analysis of metered quantities of reagents. In the set of tests to detect and ID�notificatie BB "Litmus-4" [Patent RF 2203487, Publ. 22.11.2001, IPC: G01N 31/22, G01N 33/22], which implements the closest to the present invention by the technical essence (prototype) that contains the samplers and three reagent ID for three class groups BB. Each reactant-ID is pre-applied in the form of a solution in metered quantities to your own sampler, each placed in a separate airtight container, made of two interconnected sheets of chemically resistant polymer material mainly on the basis of Dacron with a cavity under the sampler. The sampler is made of a porous material; a liquid reactant-ID VC group polyaromatics compounds contains water, dimethylformamide, dimethylsulfoxide, an alkali metal hydroxide, sulfanilate acid; reagent-the ID of the BB group preparing nitric esters and nitramines contains an aqueous solution of hydrochloric acid, alpha-naphthylamine; reactant-ID VC group ion nitrate (ammonium selitrennoye EXPLOSIVES and black powder) contains dry zinc dust.

The main disadvantage of the prototype and analogues described is the lack of stability used in rapid tests, reagents, primarily present in the solution azocompound. For prolonged storage and exposure to elevated temperatures, a sub�there is a loss of its activity, that lowers the sensitivity of VC classes of nitramines are, of preparing nitric esters and nitrate ion. The color change of the solutions also reduces the likelihood of a positive identification of a positive signal.

Despite the preliminary separation, in airtight packaging of each reagent-ID in the closest analogue, a significant increase in the stability of analytical systems for the detection of nitramines are, of preparing nitric esters and nitrate ion prevents the use of indicator dissolved form, where the reactants are solvated condition that can significantly decrease the resistance of each of them and especially azocompound.

The use of the prototype for each analysis in a separate hermetically sealed container also has its drawbacks in addition to the technological difficulties of creating such containers. Should the opening is directly in the place of analysis that given situation may be difficult and will increase the total duration of action. In addition, each kit allows you to perform only one analysis, which limits their total number to dial rapid tests, housed in a compact package.

The technical result of the present invention is to improve the reliability of the indicator detection�Oia trace amounts of nitrogen-containing EXPLOSIVES all three groups of classes in terms of ensuring high sensitivity and speed of the method and improving the overall durability of the system of chemical indicators to external influences in their application and storage components, including leaky, for several years.

This technical result is achieved by a method for the rapid detection of explosives on the basis of a set of chemical indicators for three groups of classes of nitrogen-containing compounds, comprising applying a reactive tracer material with reagents pre-deposited in metered amounts on a carrier, characterized in that as a reactive tracer material is used in the carrier with immobilized azocompounds Griess reagent in solid protected chemically modified form of covalently bonded amino group; for the rapid detection of each of the three groups of classes of nitrogen-containing explosives reactive tracer material is used as a contact probe. Said technical result is achieved by a method for the rapid detection of explosives using chemically modified azocompound Griess reagent to covalently protected amino group representing ecovalence immobilized on the surfaces of synthetic and/or natural polymeric fiber media acylated on the nitrogen atom of N-(1-naphthyl)Ethylenediamine or covalently immobilized che�ithout an amino group on the surface of the polysaccharide of N-(1-naphthyl)Ethylenediamine.

The proposed method is rapid detection of nitrogen-containing EXPLOSIVES in the flow chart of the use of indicators provides an effective analysis of all three groups of classes of compounds: vapors of nitroaromatic compounds; and nitramines are preparing nitric esters (in a single group) and nitrate ion. The use of reactive tracer-containing material outside of a solution of chemically modified azocompound Griess reagent immobilized in protected form the derivative N-(1-naphthyl)Ethylenediamine with covalently bonded amino group provides the functionality of the reagents during storage of a set of chemical indicators over a period of time not less than three years. This reactive tracer material may be out of its sealed packaging in the form of a tape (roll) or single sheets. This doesn't affect its operational and physical (color, rheology) properties. As shown used two liquid components: the basic hydroxide solution of tetraalkylammonium or alkali metal hydroxide, the acidic solution of sulfanilamide, and the metallic zinc dust, in particular, deposited on a substrate, do not limit the shelf life of a whole set of chemical indicators used in this way.

Long, within a month, the influence of external factors: extreme temperatures from minus 10�C to 50°C, relative humidity of 95±2% at an ambient temperature of 40°C, do not cause a noticeable change in performance of a set of chemical indicators that implements the claimed method.

The analysis in the temperature range 18-50°C provides coloration for polyaromatics connections almost immediately (the response time of the order 1 (C) after surface treatment reagent containing a substrate, and the typical colour of nitramines are and preparing nitric esters, nitrate - after 5-6 seconds after treatment with the acidic component of the reactants or by contact with zinc (at detection of NO3-ion). The temperature drops to minus 10°±1C increases the total time of analysis and nitramines are preparing nitric esters, nitrates up to 30-60 seconds.

In addition to the high sensitivity of the class of compounds and nitramines are preparing nitric esters, nitrate ion, provided chemically modified azocompounds Griess reagent, for the method using a reactive tracer material as the contact of the probe shown high sensitivity and selectivity detection of trace vapors of nitroaromatic compounds. This is achieved by reducing erosion of the sample (i.e. the transition of a substance in the surface of the opaque layers) after application of liquid reagents to the surface of the reactive tracer material�and, uniformly covered with immobilized modified azocompounds Griess reagent.

The surface sensitivity of the method after long-term storage of a set of chemical indicators, implementing it, defined at the level of: PETN, ammonium nitrate - 10-9g/mm2; RDX, and HMX nitroglycerin - 10-10g/mm2, TNT - 10-11g/mm2.

Information confirming the implementation of the present invention with the implementation of the proposed assignment and to achieve the specified technical result is described by the following examples.

Example 1.

For the formation of samples prepare solutions, placing an accurate sample of each compound in the volumetric flask and adding the solvent to bring the liquid level to the mark. Prepared solutions of analytes in acetonitrile: trinitrotoluene with a concentration of 5·10-6g/ml; RDX, HMX and nitroglycerin - with a concentration of 5·10-5g/ml; PETN - with a concentration of 5·10-4g/ml of ammonium nitrate Solution with a concentration of 5·10-4g/ml is prepared in water. On the surface of the slides, apply 2 µl of solutions (the diameter of the formed spot of about 5 mm), after which the straw is dried until complete evaporation of solvent.

Chemically modified form azocompound Griess reagent prepared following�m.

To obtain N-[2-(naphtalen-1 ylamino)ethyl]acetamide (I), 5.2 g (0.02 mole) of N-(1-naphthyl)Ethylenediamine dihydrochloride at room temperature, dissolved in 50 ml of 50% aqueous solution of ethanol. To the solution with constant stirring, 7 g (0,083 mol) of NaHCO3and dosed at 4 ml acetic anhydride (0.04 mol). The solution was heated to 50°C and kept under stirring. The course of the reaction is controlled by TLC (Fluka - Silica on TLS Alu foils, eluent - ethyl acetate). At the end of the exposure duration of 2 h, the reaction mixture was cooled to room temperature. Is a bright crystalline substance. The resulting acetamide was separated by filtration. Final purification is performed by column chromatography on silica gel with the elution by ethyl acetate.

The purity and identity of the obtained substances was determined according to LC-MS spectroscopy: (+head), m/z (Ot, %): 229 [M+H]+(100).

To create a reactive tracer material as a carrier of non-woven fiber "TechniCloth TX-612", laminated on one side with a polymer film. The obtained chemically modified form azocompound in an amount of 30 mg was dissolved in a solution of 0.5 g of polymethyl methacrylate in 5 ml of acetone. Non-covalent (physical) immobilization modifitsirovannoi form azocompound on the media is applying prigotovlennogo� solution on the unlaminated surface of the nonwoven material and subsequent drying. Obtained by reactive tracer material contains about 0.04 mg azocompound on 1 cm2.

Before testing reactive tracer material is subjected to aging at room temperature in an unsealed plastic bag for ~3 years.

For collecting samples from the surface of the glass on the sampler - reactive tracer material are brought into contact with the sample explosives known mass deposited by the method described above to the surface of a glass slide. The transfer of the samples is carried out in a circular wiping motion with light pressure on the laminated side of the probe. Each of the analytes is applied in different areas of the same sampler.

At room temperature on the analyzed surface immediately applied by spray 5% solution of potassium hydroxide in a mixture consisting by volume of 40% dimethyl sulfoxide, 30% ethanol and 30% water. In the place of the presence of traces of TNT almost immediately appear red-brown color. Next, on a slightly moistened surface until complete wetting is sprayed an aqueous solution containing 143,7 g/l of phosphoric acid and 20.0 g/l of sulfanilamide. Red-violet color appears at the place of the presence of traces of nitroglycerine almost immediately, in a place with traces of RDX and HMX with 3-4, PETN - �Erno for 6 seconds. For the determination of ammonium nitrate after application of the above reagents, the sampler is brought into contact with zinc dust and the method of expert evaluations conclude that the appearance of red-violet color after ~ 6 after contact.

Surface concentration of substance at which there is the appearance of color when implementing this example of the proposed method. is: for PETN, ammonium nitrate - 10-9g/mm2; RDX, HMX and nitroglycerin - 10-10g/mm2, TNT - 10-11g/mm2.

Example 2.

Similar to example 1, but the reactive tracer material contains covalently immobilized on the surface of the polysaccharide of N-(1-naphthyl)Ethylenediamine. Covalent immobilization of chemically modifitsirovannoi form azocompound on the carrier is carried out according to standard methods described in [M. A. Torlopov Synthesis of cellulose derivatives containing phosphate, amino and mercaptopropyl // proceedings of the Komi science center, Ural branch, Russian Academy of Sciences, 2011, 3 (7), pp. 23-26] and implemented as follows. To 40 g of the dried at 80°C filter paper ("the white ribbon"), placed in a conical flask, was added a solution of 1.14 g (0.01 mol) of methanesulfonamide and 2.02 g of triethylamine (0.02 mole) in 40 ml dry DMF. Maintained at 15-20°C for 24 hours. Separate paper and washed thoroughly with distilled�water, dried. Get mesilinka cellulose derivative. For nucleophilic substitution miselnih groups it was placed in the solution to 2.59 g (0.01 mol) dihydrochloride NED and 4.08 g (0.04 mol) of triethylamine in 60 ml of dry dimethylformamide. Incubated at 50°C for 48 hours. Separate the paper, thoroughly washed successively with dimethylformamide, ethanol, water, ethanol and dried.

Before testing reactive tracer material is subjected to aging by temperature control in a climatic chamber at a temperature of 50±1°C in a leaky plastic bag within 15 days. Then spend the cycle of Cycling mode: 3 hours at a temperature of minus 40±1°C, 3 hours at a temperature of 50±1°C.

Formation, collection of samples on the surface of the probe and detection of traces of EXPLOSIVES were performed as described in example 1, but at temperatures from minus 10±1°C (in acidic solution further introduced as antifreeze 15% isopropanol) to 50±1°C and relative humidity of 95±2% at an ambient temperature of 40°C±1°C. In the case of low temperature analysis time increases: the presence of traces of TNT is indicated with 3-5, RDX, and HMX nitroglycerin - within 30 s, ammonium nitrate and PETN - within 60 s. the detection Limits close to example 1 and comprise the sequence: for PETN, ammonium nitrate - 10-8g/mm2; exog�on and HMX - 10-9g/mm2nitroglycerin - 10-10g/mm2, TNT - 10-11g/mm3.

Example 3.

Similar to example 1, but to create a reactive tracer material used derivatives of N-acylated N-(1-naphthyl)ethylene diamine obtained in accordance with the following description.

Obtaining methyl[2-(naphtalen-1 ylamino)ethyl]carbamate (III). 5 g of N-(1-naphthyl)Ethylenediamine dihydrochloride at 20±5°C dissolved in a mixture of 100 ml of water and 40 ml of acetonitrile. With constant stirring dosed at 8 g NaHCO3. Then, within the hour, at 20±5°C dosed 1.5 ml methylcarbamate. The progress of the reaction was monitored by TLC (Fluka-Silica on TLS Alu foils, eluent - ethyl acetate). Upon completion of the reaction on a rotary evaporator to produce evaporation of the reaction mixture by half, the product was extracted with ethyl acetate, the extract washed with water and evaporated. The residue is purified by column chromatography on silica gel with the elution with a mixture of n-hexane and ethyl acetate 2: 1 by volume. The purity and identity of the obtained substances was determined according to LC-MS spectroscopy: (+head), m/z (ot, %): 245 [M+H]+(100).

To obtain ethyl[2-(naphtalen-1 ylamino)ethyl]carbamate (II) 5 g of N-(1-naphthyl)Ethylenediamine dihydrochloride at 20±5°C dissolved in a mixture of 100 ml of water and 40 ml of acetonitrile. With constant stirring dosed at 8 g NaHCO3. ZAT�m, within the hour, at 20±5°C is metered 1.6 ml of ethylchloride. The progress of the reaction was monitored by TLC (Fluka - Silica on TLS Alu foils, eluent - ethyl acetate). Upon completion of the reaction on a rotary evaporator to produce evaporation of the reaction mixture by half, the product was extracted with ethyl acetate, the extract washed with water and evaporated. The residue is purified by column chromatography on silica gel with the elution with a mixture of n-heptane and chloroform (1: 1 by volume. The purity and identity of the obtained substances was determined according to LC-MS spectroscopy: (+head), m/z (Ot, %): 259 [M+H]+(100), 258 [M]+(99), 213 [M-EtO]+(16).

Getting tributyl[2-(naphtalen-1 ylamino)ethyl]carbamate (IV). 5 g of N-(1-naphthyl)Ethylenediamine dihydrochloride at 20±5°C dissolved in a mixture of 100 ml of water and 40 ml of acetonitrile. With constant stirring dosed at 8 g Νą3. Then, within the hour, at 20±5°C is metered 2.2 g 1.5 ml of di-tert-BUTYLCARBAMATE. The progress of the reaction was monitored by TLC (Fluka - Silica on TLS Alu foils, eluent - ethyl acetate). Upon completion of the reaction on a rotary evaporator to produce evaporation of the reaction mixture by half, the product was extracted with ethyl acetate, the extract washed with water and evaporated. The residue is purified by column chromatography on silica gel with the elution with a mixture of n-hexane and ethyl acetate 2: 1 by volume. The purity and identity of the obtained substance was defined p� data LC-MS spectroscopy: (+head), m/z (Ot, %): 287 [M+H]+(100).

Non-covalent immobilization of the obtained chemically modified forms azocompound carried out analogously to example 1, but from solutions of 0.5 g of butadiene-Acrylonitrile rubber in 5 ml of toluene containing 100 mg each derived N-acylated N-(1-naphthyl)ethylene diamine.

In a series of experiments using the fabricated samples reactive tracer material with the immobilized derivatives of N-acylated N[-(1-naphthyl)ethylene diamine formation, collection of samples on the surface of the probe and detection of traces of EXPLOSIVES carried to classes of compounds and nitramines are preparing nitric esters as in example 1. The results are presented in table.1.

Table 1
The results of testing the sensitivity of the method when used as azocompound N-acylated N-(1-naphthyl)ethylendiamine
Azocompound; distributed conc. on the surface, mg/cm2Detectable surface concentration of the substance
RDXthe HMXTengnitroglycerin
; 0.04 (immobilization of example 1)10-10g/mm210-10g/mm210-9g/mm210-10g/mm2
I; 0,17510-10g/mm210-10g/mm210-9g/mm210-10g/mm2
II; 0,0610-9g/mm210-9g/mm210-8g/mm210-10g/mm2
III; 0,0910-9g/mm210-9g/mm210-8g/mm210-10g/mm2
IV; 0,0810-10g/mm210-10g/mm210-8g/mm210-10g/mm2

All tested derivatives acylated at the nitrogen atom of N-(1-naphthyl)ethylene diamine, ecovalence immobilized on the carrier surface, before�a component of a woven fabric of fibers based on cellulose and polyester, showed high sensitivity and performance when implementing the proposed method.

Example 4.

The surface reactive tracer material obtained as described in example 1, wipe with a cotton swab, were in contact with the substance. Thus, in different areas are plotted traces of TNT, trinitrobenzene, tetryl, dinitrotoluene, picric acid, RDX; colorless reactive surface indicator material remains after applying. The entire surface is applied alkaline solution prepared according to example 1, but potassium hydroxide is replaced by Tetramethylammonium hydroxide. Selectively manifest themselves, each with its own color, the area coated with substances: TNT - red-brown, trinitrophenol - yellow-orange, tetryl orange, picric acid yellow, dinitrotoluene - blue-blue. Then the surface is treated with an acidic solution (example 1) and after a few seconds, colorless area with traces of RDX acquires a reddish-purple color.

1. Method for the rapid detection of explosives on the basis of a set of chemical indicators for three groups of classes of nitrogen-containing compounds, comprising applying a reactive tracer material with reagents, previously applied in metered amounts to the media, otlichuy�Xia, as a reactive tracer material is used in the carrier with immobilized azocompounds Griess reagent in solid protected chemically modified form of covalently bonded amino group.

2. The Express of detecting explosives according to claim 1, characterized in that the chemically modified azocompound Griess reagent to covalently protected amino group is ecovalence immobilized on the surfaces of synthetic and/or natural polymeric fiber media acylated on the nitrogen atom of N-(1-naphthyl)Ethylenediamine.

3. The Express of detecting explosives according to claim 1, characterized in that the chemically modified azocompound Griess reagent to covalently protected amino group is a covalently immobilized via an amino group on the surface of the polysaccharide of N-(1-naphthyl)Ethylenediamine.

4. The Express of detecting explosives according to claim 1, characterized in that the reactive tracer material is used in the analysis of each of the three groups of classes of nitrogen-containing compounds as a contact probe.



 

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3 cl, 3 dwg, 1 tbl

FIELD: chemistry.

SUBSTANCE: method includes determination of the density at the fuel temperature 20°C, determination of the averaged boiling temperature Tc, °C, by calculated dependences on temperatures of boiling away of different fuel fractions, setting the density range at 20°C from 700 to 1020 kg/m3, determination of kinematic viscosity at a temperature of 50°C with the fuel density from 860 to 1020 kg/m3 and the temperature of boiling away of final fuel fraction higher than 400°C, equipping a nomogram for CI estimation with an additional scale of viscosity, matched with the Tc scale on the section from 268 to 320°C, setting the Te range from 90°C to 320°C, setting the range of the kinematic viscosity scale from 2.0 to 1000 mm2/s, setting the range of cetane index scale, units, from 0 to 70. The nomogram makes it possible to determine CI of any liquid hydrocarbon fuel (from petrol to the residual one).

EFFECT: extension of assortment of analysed fuels and increased reliability of estimation.

1 dwg, 1 tbl, 4 ex

FIELD: oil and gas industry.

SUBSTANCE: invention is related to the field of analysis of physical properties of liquids. A device contains a container for sampling with a scale with a piston and rod placed in it, software and hardware to measure time and temperature, a tube for liquid intake during sampling in order to determine the relative viscosity, a thermistor which can be installed at the tube during determination of microcone penetration, demulsifying ability and index of the liquid heating dynamics, a cone that can be installed instead of the piston on the rod by means of a threaded connection for determination of microcone penetration, a plug or a cover which can be installed into the container nipple instead of the tube for determination of microcone penetration and demulsifying ability, and a support for the container installation.

EFFECT: simplification and acceleration of the analysis as well as increase in its information content and reliability.

5 cl, 4 tbl, 10 dwg

FIELD: chemistry.

SUBSTANCE: filler used is chromogenic ion-exchange dispersed silica with covalently grafted hydrazones or formazans.

EFFECT: high sensitivity and selectivity of detecting metals.

3 tbl, 4 dwg, 14 ex

FIELD: chemistry.

SUBSTANCE: method of determining iron (II) includes preparing a sorbent and an iron (III, II) solution; adding hydroxylamine solution to reduce iron (III) to iron (II) and extracting iron (II) from the solution with the sorbent; converting the iron (II) into a complex compound on the surface of the sorbent; separating the sorbent from the solution; measuring the diffuse reflection factor of the iron (II) surface complex and determining content of iron using a calibration curve. The sorbent used is silica which is successively modified with polyhexamethylene guanidine and 3-(2-pyridyl)-5,6-di(2-furyl)-1,2,4-triazine-5',5"-disulphonic acid (Ferene S), and the diffuse reflection factor is measured at 600 nm.

EFFECT: low detection limit and wide range of determined iron content.

4 ex

FIELD: chemistry.

SUBSTANCE: method includes pretreating a sample with an inorganic reagent and determining silicon using a spectrometric method based on a blue-coloured silicon-molybdenum complex followed by re-calculation for silicon dioxide, wherein the reagent used is 20% borofluorhydric acid and treatment is carried out at 70±2°C for 40 minutes.

EFFECT: high selectivity of analysis.

4 tbl

FIELD: chemistry.

SUBSTANCE: claimed is reagent indicator truncated cone, which contains flow hollow profile, inside which sorbent with immobilised on it chromogenic reagents, is placed, with smaller base being input hole of truncated cone, overall dimensions of which are selected by the following dependences: ds = 0.25÷2.5, dl = (4÷50)·ds, ht.c = (8÷100)·ds, where ds and dl are diameters of smaller and larger bases of truncated cone, mm; ht.c is height of truncated cone, mm.

EFFECT: expressivity and increase of sensitivity of ion identification.

2 dwg, 8 ex

FIELD: chemistry.

SUBSTANCE: in order to extract iron (III) from water solutions diphenylguanidine (DPG) is applied as the first organic reagent. As the second organic reagent, salicylic acid (SA) is applied, and as solvent of organic phase chloroform is applied. In organic phase complex with molar component ratio DPG: Fe3+:SA, equal 1:1:1, is extracted. Process of iron (III) extraction is carried out at medium acidity pH=1.5-2.5 with the following detection of iron (III) by trimetric method.

EFFECT: invention makes it possible to increase selectivity and simplify process of extraction and detection of iron from water solutions.

2 cl, 5 dwg, 1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to field of analytical chemistry, namely to express-detection of explosive substances (ES) based on organic peroxides. Method is based on fixation of hydroxen peroxide, released in the process of explosive substance decomposition by indicator method. For this purpose change of indicator colour is fixed within 1 minute after contact with solid-phase material, possessing function of surface acidity and providing decomposition of ES to hydrogen oxide. Application of claimed method simplifies analysis of cyclic peroxides due to reduction of the number of analysis stages, as well as to elimination of liquid reagents, including concentrated acids and organic solvents.

EFFECT: invention provides carrying out express-analysis of trace quantities of peroxide ES outside laboratory in wide range of climatic conditions.

6 cl, 2 tbl, 7 ex

FIELD: chemistry.

SUBSTANCE: invention describes an indicator composition for the detection of disinfectants with an active substance based on quaternary ammonium compounds on surfaces of subjects and detection of disinfection completeness by aerosol spraying, which contains a 0.5-1.5% solution of trinitrotoluene in monoatomic alcohol, with propyl alcohol being applied as the monoatomic alcohol.

EFFECT: convenience and safety of application, increased term of working capacity and interval of application temperatures, protection of the environment, possibility of application at work on vertical, inclined and horizontal surfaces.

1 tbl

FIELD: chemistry.

SUBSTANCE: indicator testing means for determining content of N-methylaniline in hydrocarbon fuels is neutral aluminium oxide with potassium ferricyanide immobilised on the surface thereof, moulded in form of pellets. The method of determining content of N-methylaniline in hydrocarbon fuels using said indicator testing means is carried out based on colour change thereof after coming into contact with a sample of the analysed sample.

EFFECT: reliability of determining lower concentrations of N-methylaniline in hydrocarbon fuels.

2 cl, 1 tbl, 2 ex

FIELD: measurement equipment.

SUBSTANCE: invention relates to nondestructive examination, to study of metal properties and is intended for confirmation of exhaustion of protective properties of heat-resistant diffusive coatings on details made of carboniferous heat-resistant alloys. The method of confirmation of exhaustion of protective properties of heat-resistant diffusive coatings on details made of carboniferous heat-resistant alloys by change of physical and chemical properties of the surface layer of heat-resistant diffusive coatings during operation in conditions of high temperature, comprises application of reagent on the coating surface, and the fact of exhaustion of protective properties of the heat-resistant diffusive covering is witnessed visually by change of colour of the surface of heat-resistant diffusive coating with formation of carbon and black oxides during the process of chemical reaction between carbide phases, forming in the surface layer of the heat-resistant diffusive coating at the late stages of operation, and reagent.

EFFECT: simplicity, reliability and reliability of tests is achieved.

1 ex, 5 tbl, 10 dwg

FIELD: medicine.

SUBSTANCE: invention refers to medicine and describes using resorufin and/or toluidine blue used as an organic oxidation-reduction colouring agent, one or more polyols, glycerol, and water introduced into gelatine and/or hydroxyethylstarch, and/or methlcellulose used as additives, as an oxygen indicator. The indicator is configured so that an oxygen-sensitive product stays visible.

EFFECT: declared invention provides the light- and heat-sensitive visibly discolouring oxygen indicator.

19 cl, 6 tbl, 10 ex

FIELD: measurement equipment.

SUBSTANCE: invention relates to ecology, namely to sanitary-chemical control of the state of environment and can be used for solution of tasks for detection and measurement of harmful substance concentrations in the air. A device for detection of harmful substances in the air includes an air flow booster and the primary chemical transducer; with that, the air flow booster includes the following: a control unit providing setting of parameters of bleed air, operation and control of the device; an air path for transportation of an air flow; an air pump connected to the control unit for pumping of air through the air path; a self-contained power source, and the primary chemical transducer is connected to the air path. With that, the device includes flow and temperature sensors of the pumped air, which are arranged in the air path, as well as sensors of atmospheric pressure and relative humidity of the pumped air, which are arranged outside the air path, and the control unit includes an information display device; at least one control button and an electronic circuit providing the following: recording of data from sensors; determination of air density; control of volumetric flow of the pumped air; adjustment of air sampling time, and analogue-to-digital conversion of the obtained and transmitted data.

EFFECT: improving accuracy of taken air volumes; increasing quick action of operation of the device; control and fixation of parameters of the taken air (volumetric air flow rate, atmospheric pressure, temperature and humidity); increasing ease of use; improving accuracy of readout of information from the primary chemical transducer; providing technical control and fixation of colorimetric changes of the primary chemical transducer; reducing overall dimensions and the weight of the device; enlarging functional capabilities.

24 cl, 1 dwg

FIELD: analytical methods.

SUBSTANCE: group of inventions is directed on detecting and quantitatively determining hydrogen radicals present in water or in aqueous solution and is characterized by adding sodium 3,5-dibromo-4-nitrosobenzenesulfonate to sample to detect hydrogen radicals from coloration appearing as a result of their absorption characteristics, and additionally characterized by blowing gaseous hydrogen through 1,1-diphenyl-2-picrylhydrazide solution absorbing near 517 nm and sodium 3,5-dibromo-4-nitrosobenzenesulfonate solution at constant velocity in presence of platinum black in order to quantitatively evaluate hydrogen radical concentration using calibration curve based on correlation between coefficient of absorption near 450 nm for azo compound of sodium 3,5-dibromo-4-nitrosobenzenesulfonate and concentration of hydrogen radicals appeared.

EFFECT: increased determination accuracy and enabled analysis of hydrogen radicals in various media.

6 cl, 15 dwg, 1 tbl, 5 ex

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