CN108872226B - Reagent for rapid colorimetric detection of nitrate and nitrite - Google Patents

Abstract

The invention provides a reagent for rapidly detecting nitrate and nitrite by colorimetric detection, which is prepared from aniline compounds and strong acid. The reagent can achieve naked eye visible color change 3s after being contacted with nitrate and nitrite, and complex analytical equipment is not needed, so that low-cost, instant and trace detection of nitrate and nitrite is realized. In addition, the reagent is easy to prepare, simple and convenient to operate, high in sensitivity and low in cost, overcomes the defects that nitrate cannot be directly detected in a colorimetric way, the sensitivity is low, the reaction time is long and the like in the prior art, and provides effective technical support for trace detection of nitrate and nitrite in non-standard explosives.

Description

Reagent for rapid colorimetric detection of nitrate and nitrite

Technical Field

The invention belongs to the field of non-standard explosive detection, and provides a reagent for rapidly detecting nitrate and nitrite through colorimetric detection.

Background

Terrorist attack events frequently occur in the last 20 years, and seriously threaten the life and property safety of people all over the world (analytical chimica acta,2015,893: 1-13; Nanoscale, 2016, 8: 1305-1308; Forensic science international,2014,242: 228-235). Non-standard explosives are the first choice for terrorists because of their low cost, readily available raw materials, and low susceptibility to detection (Talanta, 2016, 161: 219-227). Nonstandard explosives are generally based on inorganic energetic oxidizers such as nitrates, chlorates or perchlorates (TrAC Trends in Analytical Chemistry,2014,56: 27-36). Nitrates (ammonium nitrate, potassium nitrate, sodium nitrate, etc.) are among the most commonly used agricultural fertilizers, and when mixed with any fuel (gasoline, diesel, sugar, charcoal, flour, etc.) they can easily produce explosives (accessories of explosives detection. elsevier, 2011). The boston marathon explosive case noted in 2013 is an explosive attack using black powder (potassium nitrate, sulfur and charcoal) that resulted in 3 deaths and 170 injuries (Forensic Science International,2014,242: 228-235). Furthermore, it has been statistically found by the authorities that most vehicular explosive attacks are the use of ammonium nitrate explosives, including the Russian-Homalus explosive attack which is heard by hackers (Defence Today,2008,4649: 46-49). The "Ireland Junior" well known to the republic of Ondardy, which utilizes a mixture of ammonium nitrate and candy, produced a number of terrorist attacks in North Ireland and London (Science and Juustice, 2009,49: 73-80). In addition, the Egypt (ETA) of the Spanish terrorist organization, the Columbia revolutionary Force (FARC), and the extreme molecules of Balstein use ammonium nitrate-petroleum for terrorist attack activities (Applied Magnetic Resonance,2012,43: 557-566). It is further reported that nitrite can be used as an oxidant component in non-standard Explosives (applications of Explosives Detection,2009, 11-26). Therefore, researchers have developed many detection methods for nitro explosives. For example, the M.R. Mahmoudian group of university of Malaysia successfully achieved nitrate detection using electrochemical methods with limits of detection as low as 0.4535. mu.M (Journal of electrochemical Chemistry, 2015, 751: 30-36). The Paul J.Worsfold project group of the university of Primedes, UK achieved detection limits of 0.02 μ g N/L and 0.02 μ g N/L for nitrate and nitrite, respectively, using chemiluminescence (Luminesconce, 2012,27.5: 419-425). The Hitoshi Kodamatani project group of the university of Kagoshima, Japan, has achieved detection of nitrate and nitrite in river water, pond water, rainwater, commercial mineral water, and tap water by liquid Chromatography (Journal of Chromatography A,2009,1216: 3163-3167). The Shin-ichi Wakida project group of the national institute of Industrial and technology successfully achieved detection of nitrite and nitrate at limits of 2.6 and 1.5. mu.M by capillary electrophoresis (Journal of Chromatography A,2004,1051: 185-191). The Andrea K Nussler subject group of Berlin university medicine in Germany realizes the fluorescence detection of nitrite by utilizing the phenomenon that 2, 3-diaminonaphthalene can react with nitrite to form 2, 3-nitronaphthalene and generate stronger fluorescence (Nature Protocols,2006,1, 2223-2226). The Jianguo Li project group of Suzhou university successfully realizes the detection of nitrite by using a water-soluble CdSe quantum dot electrochemical Luminescence method (Luminescience, 2013,28: 551-556). Among The numerous detection methods, spectroscopic techniques are widely used due to their low detection limit and ease of operation, including ultraviolet-visible analysis (Analytical chip acta,1994,299:81-90), chemiluminescence analysis (Fresenius' Journal of Analytical Chemistry,2000,367.3: 264-269), fluorescence analysis (Analytical Letters,2000,33: 1869-3), infrared spectroscopy (Journal of Plant Nutrition,2000,23:79-90), Raman spectroscopy (The Journal of Chemical Physics,1999,110:2202-2207), molecular vacancy emission spectroscopy (Analytical, 1989,114.5: 563-566). However, these methods of detecting nitrate by chemical reaction, including the most commonly used grits reagent, are all performed by reducing nitrate to a more chemically active nitrite (analytical chimica acta,1995,308: 413-424). According to extensive literature research, only the Michael Gozin subject group of Delavav university in Israel utilizes the characteristic that nitrate can oxidize thioether into sulfoxide under a molybdenum-copper catalytic system, and the aim of directly detecting nitrate by a fluorescence method is successfully achieved (Organic letters,2011,13: 5532-5535). The colorimetric method is the most promising method in the detection field because of simple operation and visual and reliable result. Unfortunately, however, to date, no one has been able to directly detect nitrate species by chemical colorimetric methods. In order to realize the on-site rapid detection and analysis of suspicious nitrate explosives, the development of a reagent capable of directly detecting nitrate through colorimetric detection becomes an urgent and most challenging world problem.

Based on the above, the invention develops a reagent for rapidly and colorimetrically detecting nitrate and nitrite. The reagent mainly utilizes strong acid to improve the nitrification capability of nitrate, and nitrate is more prone to nitrify para position of a strong electron donating group, so that an aniline compound with the strong electron donating group is selected to generate a brown yellow nitrification product. Thereby achieving the purpose of rapid colorimetric detection of nitrate. In addition, the reagent is rapid, sensitive, high in selectivity, simple to operate and beneficial to popularization and application.

Disclosure of Invention

The invention aims to provide a reagent for rapidly detecting nitrate and nitrite through colorimetry, which is prepared from aniline compounds, strong acid and ultrapure water, and the detection reagent disclosed by the invention has extremely low detection limit (10 mu M of naked eye detection limit) and extremely high selectivity on nitrate and nitrite, so that the detection of nitrate and nitrite components in non-standard explosive raw materials can be ensured. The reagent is immediately discolored after being contacted with nitrate and nitrite, and complex analytical equipment is not needed, so that low-cost, instant and trace detection of nitrate and nitrite is realized. The reagent has simple operation, high sensitivity and low cost. Overcomes the defects of complex synthesis, low sensitivity, long reaction time and the like of probe molecules used in the colorimetric detection method of nitrate and nitrite in the prior art, and provides an effective technical means for the field of nonstandard explosive raw material detection.

The invention relates to a reagent for rapid colorimetric detection of nitrate and nitrite, which is prepared by dissolving aniline compounds in an ultrapure water solution with strong acid of a certain concentration, wherein:

the aniline compound is N-benzoylaniline, 2',5' -diethoxyphenylanilide, 3-amino-4-methoxyethoxy acetanilide, 4' -diaminobenzanilide or N-acetanilide, and the content of the aniline compound in the solution is 10mg/L-40 g/L;

the strong acid is perchloric acid, hydroiodic acid, hydrochloric acid or sulfuric acid, and the concentration of the strong acid is 30-98%;

the solvent is ultrapure water;

aniline compounds are dissolved in strong acid diluted by ultrapure water, and the mixture is uniformly stirred for 20-30min to obtain the reagent for colorimetric detection of nitrate and nitrite.

The invention relates to a reagent for rapid colorimetric detection of nitrate and nitrite, which comprises the following specific steps:

preparing a detection reagent:

weighing aniline compounds of 0.1mg, 0.2mg, 0.4mg, 0.6mg, 0.8mg, 1mg, 2mg, 4mg, 6mg, 8mg, 10mg, 40mg, 70mg, 100mg and 400mg and dissolving the aniline compounds in strong acid diluted by ultrapure water to obtain strong acid-aniline solutions with the concentrations of 10mg/L, 20mg/L, 40mg/L, 60mg/L, 80mg/L, 100mg/L, 200mg/L, 400mg/L, 600mg/L, 800mg/L, 1g/L, 4g/L, 7g/L, 10g/L and 40 g/L;

diluting aniline-strong acid solutions with different concentrations by using ultrapure water until the concentration of strong acid is 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% and 98%, and obtaining the detection reagent with the aniline compound concentration of 10mg/L-40g/L and the strong acid concentration of 30% -98%;

the prepared detection reagent is applied to colorimetric detection of nitrate and nitrite:

weighing KNO₃Dissolved in ultrapure water, formulated as an aqueous solution of nitrate at a concentration of 1M, 900mM, 800mM, 700mM, 600mM, 500mM, 400mM, 300mM, 200mM, 100mM, 90mM, 80mM, 70mM, 60mM, 50mM, 40mM, 30mM, 20mM, 10mM, 9mM, 8mM, 7mM, 6mM, 5mM, 4mM, 3mM, 2mM, 1mM, 900. mu.M, 800. mu.M, 700. mu.M, 600. mu.M, 500. mu.M, 400. mu.M, 300. mu.M, 200. mu.M, 100. mu.M, 90. mu.M and 80. mu.M;

weighing NaNO₂Dissolved in ultrapure water, formulated as an aqueous solution of nitrite at a concentration of 1M, 900mM, 800mM, 700mM, 600mM, 500mM, 400mM, 300mM, 200mM, 100mM, 90mM, 80mM, 70mM, 60mM, 50mM, 40mM, 30mM, 20mM, 10mM, 9mM, 8mM, 7mM, 6mM, 5mM, 4mM, 3mM, 2mM, 1mM, 900. mu.M, 800. mu.M, 700. mu.M, 600. mu.M, 500. mu.M, 400. mu.M, 300. mu.M, 200. mu.M and 100. mu.M;

measuring 300 mu L of detection reagent into a 96-well plate by using a pipette, respectively adding 3 mu L of nitrate radical or nitrite radical solution with different concentrations, scanning color pictures before and after reaction by using a flat scanner after 3s, and determining the naked eye identification detection limit of the reagent; meanwhile, comparing color changes before and after reaction, and taking an Euclidean distance fitting curve of RGB;

respectively wiping trace KNO with sampling paper₃、NaNO₃、NH₄NO₃、Zn(NO₃)₂、NaNO₂、NH₄NO₂、KClO₃And NH₄Cl, 1-2 drops of detection reagent were dropped and the color change was observed to determine whether nitrate or nitrite was present.

The reagent can detect not only nitrate or nitrite in liquid, but also trace solid nitrate or nitrite residue. In addition, the reagent has excellent selectivity for common inorganic salt interferents.

The reagent for rapid colorimetric detection of nitrate and nitrite is mainly used for detecting nitrate and nitrite components in non-standard explosives, and solves the problem that the nitrate component cannot be directly, rapidly, visually and inexpensively detected at present.

Compared with the prior art, the invention has the beneficial effects that:

1. the raw materials of the reagent used in the invention can be purchased from commercial markets;

2. the detection reagent can sensitively and selectively detect nitrate and nitrite;

3. the detection reagent disclosed by the invention is quick in reaction, and can detect nitrate and nitrite within 3 s;

4. the detection reagent provided by the invention is used for detecting nitrate and nitrite, does not need complex analysis equipment, and can be directly identified and detected by naked eyes;

5. the detection reagent disclosed by the invention does not need to carry out any pretreatment on the object to be detected, is simple to operate and convenient to popularize and apply, has low detection limit, strong anti-interference performance and short reaction time, and can completely realize the purpose of carrying out real-time colorimetric detection on nitrate and nitrite at low cost.

Drawings

FIG. 1 is a graph showing that a flat-bed scanner scans a detection reagent containing N-benzanilide in 50% perchloric acid at a concentration of 10mg/L to 40g/L with 10mM KNO₃The color change before and after the reaction and the color before and after the reaction are subtracted to obtain a picture;

FIG. 2 shows that the content of N-benzanilide treated with RGB data is 50%Detection reagent with concentration of 10mg/L-40g/L in perchloric acid and 10mM KNO₃A color change curve after reaction;

FIG. 3 shows that the reagent for detecting 10mM KNO obtained by dissolving 4g/L of 3-amino-4-methoxyethoxyacetanilide treated with RGB data in 50% -98% sulfuric acid according to the present invention₃The obtained map, wherein the inset is a picture obtained by scanning color change before and after reaction of the detection reagent and color subtraction before and after reaction by a flat-bed scanner;

FIG. 4 shows that the reagent prepared by dissolving 4,4' -diaminobenzanilide in 50% hydroiodic acid at a concentration of 0.1g/L is detected by a flat-panel scanner to detect KNO at a concentration of 0-10mM₃Obtaining an image;

FIG. 5 shows the detection of KNO of 0.8. mu.M to 10mM by a reagent prepared by dissolving 0.1g/L of 4,4' -diaminobenzanilide in 50% hydroiodic acid in RGB data processing according to the present invention₃Obtaining a map;

FIG. 6 is a graph showing that 0.01g/L of N-acetanilide is scanned by a flat-panel scanner and 0-10mM of NaNO is detected by a reagent prepared by dissolving N-acetanilide in 30% hydrochloric acid₂Obtaining an image;

FIG. 7 shows that the reagent for detecting 1. mu.M-10 mM NaNO obtained by dissolving 0.01g/L acetanilide in 30% hydrochloric acid after RGB data processing of the invention₂Obtaining the map.

Detailed Description

The present invention will be further illustrated by the following specific examples, but the present invention is not limited to these examples.

Example 1

Respectively dissolving 0.1mg, 0.2mg, 0.4mg, 0.6mg, 0.8mg, 1mg, 2mg, 4mg, 6mg, 8mg, 10mg, 40mg, 70mg, 100mg and 400mg of benzanilide in 10mL of 70% perchloric acid at room temperature, and uniformly stirring to obtain a reagent for rapidly and colorimetrically detecting nitrate and nitrite;

mixing the prepared reagents with KNO of 1M in different concentrations₃The scanning patterns of the plate before and after the reaction are shown in FIG. 1, and it can be seen from FIG. 1 that: the reagent before reaction gradually changes from colorless to dark yellow along with the increase of the concentration of the benzanilide, and the solution after reaction gradually changes from light yellow to brown yellow; to is coming toThe change of the color before and after the reaction can be intuitively contrasted, and the color after the reaction is directly subtracted from the color before the reaction, which is shown in the third row of the picture 1, so that the following can be seen: the color difference between the solution after the reaction and the solution before the reaction is gradually changed from black to brown black along with the increase of the concentration of the benzanilide; further, the Euclidean distance between the color of the solution after the reaction and that before the reaction is plotted as an ordinate, and the concentration of benzanilide as an abscissa show that: the change of Euclidean distance is clearly shown in FIG. 2 when the concentration of N-benzanilide is in the range of 10mg/L to 40 g/L.

Example 2

Diluting 98% concentrated sulfuric acid to 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% and 95% with ultrapure water at room temperature, then weighing 40mg of 3-amino-4-methoxyethoxy acetanilide, dissolving in 10mL of sulfuric acid with different concentrations, and uniformly stirring to obtain a reagent for rapidly colorimetric detection of nitrate and nitrite;

mixing the prepared reagents with different sulfuric acid concentrations and 1M KNO₃The scans of the plates before and after the reaction are shown in FIG. 3 (inset), and it can be seen that: the reagent before reaction gradually changes from colorless to light yellow along with the increase of the concentration of the sulfuric acid, the color reaches the deepest when the concentration of the sulfuric acid is 70 percent, and then gradually changes from light yellow to colorless along with the increase of the concentration of the sulfuric acid; the reacted solution gradually changes from light yellow to brown yellow, and then gradually changes from brown yellow to light yellow along with the increase of the concentration of the sulfuric acid; in order to further compare the color change of the solution before and after the reaction, the Euclidean distance before and after the reaction is plotted as ordinate and the concentration of sulfuric acid is plotted as abscissa (as shown in FIG. 3), it can be seen that: the change of the Euclidean distance can be obviously seen when the concentration of the sulfuric acid is between 50 and 98 percent.

Example 3

Diluting 57% hydriodic acid to 50% with ultrapure water at room temperature, then weighing 1mg of 4,4' -diaminobenzanilide, dissolving in 10mL of 50% hydriodic acid, and uniformly stirring to obtain a reagent for rapidly colorimetric detection of nitrate and nitrite;

mixing the prepared detection reagent with 10mM, 9mM, 8mM, 7mM, 6mM, 5mM, 4mM, 3mM,2mM, 1mM, 900. mu.M, 800. mu.M, 700. mu.M, 600. mu.M, 500. mu.M, 400. mu.M, 300. mu.M, 200. mu.M, 100. mu.M, 90. mu.M, 80. mu.M, 70. mu.M, 60. mu.M, 50. mu.M, 40. mu.M, 30. mu.M, 20. mu.M, 10. mu.M, 9. mu.M, 8. mu.M, 7. mu.M, 6. mu.M, 5. mu.M, 4. mu.M, 3. mu.M, 2. mu.M, 1. mu.M, 0.9. mu.M, 0.8. mu.M₃Reacting the ultrapure water solution, and scanning by using a flat plate to obtain the color change before and after the reaction as shown in FIG. 4; as can be seen from fig. 4: with KNO₃The solution gradually changes from colorless to yellow when the concentration of KNO increases₃The color change can be seen by naked eyes when the concentration is 10 mu M; in order to more accurately compare the color change of the solution before and after the reaction, the Euclidean distance before and after the reaction is taken as the ordinate, KNO₃The concentration of (c) is plotted on the abscissa (as shown in fig. 5), and it can be seen that: with KNO₃Increasing the concentration, the Euclidean distance gradually increases; FIG. 5 by versus Euclidean distance with KNO₃The concentration change of (a) is subjected to exponential fitting, and the following can be seen: euclidean distance and KNO₃The concentrations showed a very good exponential relationship, so that the Euclidean distance was used for KNO₃Quantitative analysis was performed.

Example 4

Diluting 38% hydrochloric acid to 30% with ultrapure water at room temperature, then weighing 0.1mg of N-acetanilide, dissolving in 10mL of 30% hydrochloric acid, and uniformly stirring to obtain a reagent for rapidly colorimetric detection of nitrate and nitrite;

the prepared detection reagent is mixed with NaNO at 10mM, 9mM, 8mM, 7mM, 6mM, 5mM, 4mM, 3mM, 2mM, 1mM, 900. mu.M, 800. mu.M, 700. mu.M, 600. mu.M, 500. mu.M, 400. mu.M, 300. mu.M, 200. mu.M, 100. mu.M, 90. mu.M, 80. mu.M, 70. mu.M, 60. mu.M, 50. mu.M, 40. mu.M, 30. mu.M, 20. mu.M, 10. mu.M, 9. mu.M, 8. mu.M, 7. mu.M, 6. mu.M, 5. mu.M, 4. mu.M, 3. mu.M, 2. mu.M, 1. mu.M₂Ultra pure water solution reaction, color change before and after the reaction is scanned by a flat plate as shown in FIG. 6; as can be seen from fig. 6: with NaNO₂The solution with increasing concentration gradually changes from colorless to yellow; in order to more accurately compare the color change of the solution before and after the reaction, the Euclidean distance before and after the reaction is taken as the ordinate, NaNO₂The concentration of (c) is plotted on the abscissa (as shown in fig. 7), and it can be seen that: with NaNO₂Increasing the concentration, the Euclidean distance gradually increases; drawing (A)7 by vs. Euclidean distance with NaNO₂The concentration change of (a) is subjected to exponential fitting, and the following can be seen: euclidean distance and NaNO₂The concentrations exhibit a very good exponential relationship, so that the Euclidean distance can be used for NaNO₂Quantitative analysis was performed.

Example 5

Diluting perchloric acid with the concentration of 70% to 60% by using ultrapure water at room temperature, then weighing 0.4mg of benzanilide, dissolving the benzanilide in 10mL of 60% perchloric acid, and uniformly stirring to obtain a reagent for rapidly colorimetric detection of nitrate and nitrite;

wiping trace KNO with sampling paper₃After the solid residue, 1-2 drops of detection reagent are dripped into the center of the sampling paper, and after 3 seconds, the following results are obvious: the sampling paper center can be quickly changed from colorless to yellow; the test object is proved to contain non-standard explosive raw material nitrate.

Example 6

Diluting 57% hydriodic acid with ultrapure water to 40% at room temperature, then weighing 0.1mg of 2',5' -diethoxyphenylanilide, dissolving in 10mL of 40% hydriodic acid, and uniformly stirring to obtain a reagent for rapidly colorimetric detection of nitrate and nitrite;

wiping micro NaNO with sampling paper₃After the solid residue, 1-2 drops of detection reagent are dripped into the center of the sampling paper, and after 3 seconds, the following results are obvious: the center of the sampling paper can be rapidly changed from colorless to yellow, and the fact that the to-be-detected object contains nitrate which is a non-standard explosive raw material is proved.

Example 7

Diluting hydrochloric acid with the concentration of 38% to 30% by using ultrapure water at room temperature, then weighing 6mg of 4,4' -diaminobenzanilide, dissolving in 10mL of 38% hydrochloric acid, and uniformly stirring to obtain a reagent for rapidly colorimetric detection of nitrate and nitrite;

wiping trace NH with sampling paper₄NO₃After the solid residue, 1-2 drops of detection reagent are dripped into the center of the sampling paper, and after 3 seconds, the following results are obvious: the center of the sampling paper can be rapidly changed from colorless to yellow, and the fact that the to-be-detected object contains nitrate which is a non-standard explosive raw material is proved.

Example 8

Diluting concentrated sulfuric acid with the concentration of 98% to 75% by using ultrapure water at room temperature, then weighing 8mg of 3-amino-4-methoxyethoxy acetanilide, dissolving the 3-amino-4-methoxyethoxy acetanilide in 10mL of 75% sulfuric acid, and uniformly stirring to obtain a reagent for rapidly colorimetric detection of nitrate and nitrite;

wiping trace Zn (NO) with sampling paper₃)₂After the solid residue, 1-2 drops of detection reagent are dripped into the center of the sampling paper, and after 3 seconds, the following results are obvious: the center of the sampling paper can be rapidly changed from colorless to yellow, and the fact that the object to be detected contains nitrite which is a non-standard explosive raw material is proved.

Example 9

Diluting perchloric acid with the concentration of 70% to 60% by using ultrapure water at room temperature, then weighing 10mg of N-acetanilide, dissolving the N-acetanilide in 10mL of 60% perchloric acid, and uniformly stirring to obtain a reagent for rapidly colorimetric detection of nitrate and nitrite;

wiping micro NaNO with sampling paper₂After the solid residue, 1-2 drops of detection reagent are dripped into the center of the sampling paper, and after 3 seconds, the following results are obvious: the center of the sampling paper can be rapidly changed from colorless to yellow, and the fact that the object to be detected contains nitrite which is a non-standard explosive raw material is proved.

Example 10

Diluting hydrochloric acid with the concentration of 38% to 35% by using ultrapure water at room temperature, then weighing 0.4mg of 2',5' -diethoxyphenylanilide, dissolving the 2',5' -diethoxyphenylanilide in 10mL of 35% hydrochloric acid, and uniformly stirring to obtain a reagent for rapidly colorimetric detection of nitrate and nitrite;

wiping trace NH with sampling paper₄NO₂After the solid residue, 1-2 drops of detection reagent are dripped into the center of the sampling paper, and after 3 seconds, the following results are obvious: the center of the sampling paper can be rapidly changed from colorless to yellow, and the fact that the to-be-detected object contains nitrate which is a non-standard explosive raw material is proved.

Example 11

Diluting 57% hydriodic acid to 55% with ultrapure water at room temperature, then weighing 0.2mg of 3-amino-4-methoxyethoxy acetanilide, dissolving in 10mL of 55% hydriodic acid, and uniformly stirring to obtain a reagent for rapidly colorimetric detection of nitrate and nitrite;

wiping trace KClO with sampling paper₃After the solid residue is obtained, 1-2 drops of detection reagent are dripped into the center of the sampling paper, and after 3 seconds, the center of the sampling paper has no color change, so that the object to be detected does not contain non-standard explosive raw material nitrate or nitrite.

Example 12

Diluting 57% hydriodic acid with ultrapure water to 45% at room temperature, then weighing 0.6mg of benzanilide, dissolving the benzanilide in 10mL of 45% hydriodic acid, and uniformly stirring to obtain a reagent for rapidly colorimetric detection of nitrate and nitrite;

wiping trace NH with sampling paper₄After Cl solid residues, 1-2 drops of detection reagent are dripped into the center of sampling paper, and after 3 seconds, the center of the sampling paper has no color change, so that the object to be detected does not contain non-standard explosive raw material nitrate or nitrite.

Although the above embodiments describe the present invention, it is to be understood that the ratio of the reagent components in the present invention can be adjusted and the hypochlorite test used in other fields can be applied without departing from the spirit of the present invention, and these changes are also within the scope of the present invention.

Claims (1)

1. A reagent for detecting nitrate and nitrite by rapid colorimetric method is characterized in that the reagent is prepared by aniline compounds, strong acid and ultrapure water, wherein:

the aniline compound is N-benzoylaniline, 2',5' -diethoxyphenylanilide, 3-amino-4-methoxyethoxy acetanilide, 4' -diaminobenzanilide or N-acetanilide, and the content of the aniline compound in the solution is 10mg/L-40 g/L;

the strong acid is perchloric acid, hydroiodic acid, hydrochloric acid or sulfuric acid, and the concentration of the strong acid is 30-98%;

the solvent is ultrapure water;

aniline compounds are dissolved in strong acid diluted by ultrapure water, and the mixture is uniformly stirred for 20-30min to obtain the reagent for colorimetric detection of nitrate and nitrite.

Images