阅读说明：本技术 一种现场快速检测蔗糖的比色试剂及其制备方法 (Colorimetric reagent for rapidly detecting sucrose on site and preparation method thereof ) 是由 窦新存 张天实 于 2019-10-26 设计创作，主要内容包括：本发明提供了一种现场快速检测蔗糖的比色试剂及其制备方法,该试剂是由A,B两部分组成,A是由化学试剂N-甲基吡咯烷酮磺酸盐和甲基氯化咪唑鎓配制而成；B是由化学试剂巴比妥酸、对甲苯胺、冰醋酸和异丙醇配制而成；其主要利用在二元离子液体下,蔗糖可以被快速催化脱水生成羟甲基糠醛,而羟甲基糠醛可以和巴比妥酸与对甲苯胺形成樱桃红色复合物,实现比色检测。本试剂对于含有杂质的样品可以以较快的速度(1min内)实现微量(＞50μg)检测。另外,本试剂原料易得,制备简便,无危险,选择性强,操作简单,可以有效避免传统的糖类检测方法中,无法区分醛类,醇类等类似物的问题。(The invention provides a colorimetric reagent for rapidly detecting sucrose on site and a preparation method thereof, wherein the reagent consists of a reagent A and a reagent B, wherein the reagent A is prepared from a chemical reagent N-methylpyrrolidone sulfonate and methylimidazolium chloride; b is prepared by chemical reagents of barbituric acid, p-toluidine, glacial acetic acid and isopropanol; the method is mainly characterized in that under the binary ionic liquid, sucrose can be quickly catalyzed and dehydrated to generate hydroxymethyl furfural, and the hydroxymethyl furfural, barbituric acid and p-toluidine can form a cherry red compound to realize colorimetric detection. The reagent can realize trace (> 50 mu g) detection for a sample containing impurities at a higher speed (within 1 min). In addition, the reagent has the advantages of easily obtained raw materials, simple and convenient preparation, no danger, strong selectivity and simple operation, and can effectively avoid the problem that aldehydes, alcohols and other analogues cannot be distinguished in the traditional saccharide detection method.)

1. A colorimetric reagent for rapidly detecting sucrose on site is characterized in that the reagent consists of two parts A and B, wherein A is prepared from chemical reagents of N-methylpyrrolidone sulfonate and methylimidazolium chloride according to a molar ratio of 0.5-2.5: 10; b is prepared from barbituric acid (1-5 wt.%), p-toluidine (4-8), glacial acetic acid (4-8) and isopropanol (34-42).

2. The method for preparing the colorimetric reagent for rapidly detecting sucrose on site according to claim 1, which comprises the following steps:

preparing a detection reagent A:

a. putting 10mL of N-methylpyrrolidone into a flask, slowly adding 6mL of concentrated sulfuric acid under an ice bath environment, slowly stirring for 24h at room temperature, and washing for 3 times respectively by using diethyl ether and ethyl acetate to obtain N-methylpyrrolidone sulfonate;

b. putting 5g of 1-methylimidazole into 4 flasks, respectively adding 1.1-time molar ratio of chloroethane, n-butyl chloride, n-hexane chloride and n-octane chloride, reacting for 24 hours in a water bath at the temperature of 60 ℃, and washing for 3 times by using ethyl acetate to obtain methylimidazolium chloride of which the 1 position is ethyl, butyl, hexyl or octyl respectively;

c. fully and uniformly mixing the N-methylpyrrolidone sulfonate obtained in the step a and the methylimidazolium chloride obtained in the step b in a molar ratio of 0.5-2.5:10 in a water bath at the temperature of 50 ℃, cooling and packaging in a reagent bottle A of the kit;

preparing a detection reagent B:

d. weighing 2-10g of barbituric acid in a beaker, adding 40mL of water, fully dissolving in a water bath at the temperature of 50 ℃, and cooling to a volume of 100mL in a volumetric flask;

e. uniformly mixing p-toluidine, glacial acetic acid and isopropanol according to the volume ratio of 1:1:6-10, and placing the mixture in a black reagent bottle for storage;

f. mixing the barbituric acid obtained in the step d with the mixed solution obtained in the step e according to the volume ratio of 1:1, fully and uniformly stirring, and then placing the mixture in a black reagent bottle B for storage, wherein the mass fraction of the barbituric acid in the reagent B is 1% -5%, the volume fraction of p-toluidine is 4% -8%, the volume fraction of glacial acetic acid is 4% -8%, and the volume fraction of isopropanol is 34% -42%;

the prepared detection reagent is used for colorimetric detection of sucrose:

g. after a trace amount of sucrose is wiped by sampling paper, the detection reagent A is firstly dripped, then the reagent B is dripped on the filter paper containing a sucrose sample, and whether cherry red compound is generated or not is observed, so that the existence of the sucrose is determined.

Technical Field

The invention provides a sucrose on-site colorimetric detection reagent with stable property and strong specificity and a preparation method thereof, which can realize on-site rapid detection of sucrose.

Background

Sucrose is one of the most common sweeteners in life, often used as a food additive. However, sucrose content is severely limited in low sugar or sugar-free products for some diabetics as well as infants and young children. Since sucrose is less expensive than other non-sugar sweeteners, some illicit merchants will incorporate sucrose in low-sugar or sugar-free foods. Therefore, there are some qualitative or quantitative detection means for sucrose in the field of food safety. In addition, terrorism activities in the world are rampant and seriously threaten the life and property safety of people. The control of standard explosives in China is strict, and non-standard explosives have the characteristics of wide sources, easiness in obtaining, easiness in manufacturing, easiness in implementation and the like, so that the standard explosives become the most common explosives for terrorists. Since sucrose has the characteristics of easy combustion, easy acquisition, energy supply after combustion and large amount of gas generation, it is a common fuel in non-standard explosives. The sucrose is ubiquitous in life, so that the control is difficult to realize, the sucrose does not have the property of independently making explosives, so that the sucrose is not paid much attention, and the detection of the sucrose is not realized in explosion cases and explosion searching fields.

In conclusion, the rapid field analysis of sucrose has great significance in food safety and social security. The colorimetric detection is very suitable for the detection of the sucrose in the scenes as a simple, direct and intuitive detection means. Currently, the main detection methods for colorimetric detection of sucrose are Fehling reagent method, Benedict reagent method and iron method. These methods all use the reducibility of glucose obtained by hydrolysis of sucrose, and for example, in the iron method, in an alkaline solution environment, the following reaction occurs: c₆H₁₂O₆+6K₃[Fe(CN)₆]+6KOH＝(CHOH)₄·(COOH)₂+6K₄[Fe(CN)₆]+4H₂O, the solution turns from red to yellow, but because the reducing sugar is not very reducing, such reactions must be carried out in a hot water bath, and the reaction is slow, which is not favorable for on-site analysis. The detection method without utilizing the property of reducing sugar mainly comprises a Molish reagent method and an anthrone sulfuric acid method. According to the method, the hydroxymethyl furfural is rapidly dehydrated in the presence of concentrated sulfuric acid to generate the hydroxymethyl furfural, and the heat generated by dehydration can promote the hydroxymethyl furfural and phenol or quinone substances to form a compound, so that colorimetric detection is performed. However, such reactions require concentrated sulfuric acid to treat the sample, which is very dangerous and can create unpredictable field conditions in the presence of impurities.

Disclosure of Invention

The invention aims to provide a colorimetric reagent for rapidly detecting sucrose on site and a preparation method thereof, wherein the reagent consists of two parts, namely A and B, wherein A is a chemical reagent N-methylpyrrolidone sulfonate (NMP [ HSO ]₄]) And methylimidazolium chloridePreparing; b is prepared from barbituric acid, p-toluidine, glacial acetic acid, isopropanol and ultrapure water. The method is mainly characterized in that under the binary ionic liquid, sucrose can be quickly catalyzed and dehydrated to generate hydroxymethyl furfural, and the hydroxymethyl furfural, barbituric acid and p-toluidine can form a cherry red compound to realize colorimetric detection. The method is simple to operate and low in cost, and can realize trace (> 50 mu g) detection at a high speed (within 1 min) for samples containing a large amount of impurities. In addition, the problem that aldehydes and alcohols cannot be distinguished by a Fehling reagent, a Benedict reagent and a silver ammonia reagent in the traditional saccharide detection method can be effectively solved by utilizing the property that sucrose is converted into hydroxymethylfurfural in the binary ionic liquid.

The invention relates to a colorimetric reagent for rapidly detecting sucrose on site, which consists of two parts, namely A and B, wherein the A is prepared from a chemical reagent, namely N-methylpyrrolidone sulfonate and methylimidazolium chloride according to a molar ratio of 0.5-2.5: 10; b is prepared from barbituric acid (1-5 wt.%), p-toluidine (4-8), glacial acetic acid (4-8) and isopropanol (34-42).

The preparation method of the colorimetric reagent for rapidly detecting sucrose on site comprises the following steps:

preparing a detection reagent A:

a. putting 10mL of N-methylpyrrolidone into a flask, slowly adding 6mL of concentrated sulfuric acid under an ice bath environment, slowly stirring for 24h at room temperature, and washing for 3 times respectively by using diethyl ether and ethyl acetate to obtain N-methylpyrrolidone sulfonate;

b. putting 5g of 1-methylimidazole into 4 flasks, respectively adding 1.1-time molar ratio of chloroethane, n-butyl chloride, n-hexane chloride and n-octane chloride, reacting for 24 hours in a water bath at the temperature of 60 ℃, and washing for 3 times by using ethyl acetate to obtain methylimidazolium chloride of which the 1 position is ethyl, butyl, hexyl or octyl respectively;

c. fully and uniformly mixing the N-methylpyrrolidone sulfonate obtained in the step a and the methylimidazolium chloride obtained in the step b in a molar ratio of 0.5-2.5:10 in a water bath at the temperature of 50 ℃, cooling and packaging in a reagent bottle A of the kit;

preparing a detection reagent B:

d. weighing 2-10g of barbituric acid in a beaker, adding 40mL of water, fully dissolving in a water bath at the temperature of 50 ℃, and cooling to a volume of 100mL in a volumetric flask;

e. uniformly mixing p-toluidine, acetic acid and isopropanol according to the volume ratio of 1:1:6-10, and placing the mixture in a black reagent bottle for storage;

f. mixing the barbituric acid obtained in the step d with the mixed solution obtained in the step e according to the volume ratio of 1:1, fully and uniformly stirring, and then placing the mixture in a black reagent bottle B for storage, wherein the barbituric acid in the reagent B accounts for 1-5% by mass, the p-toluidine accounts for 4-8% by volume, the glacial acetic acid accounts for 4-8% by volume, and the isopropanol accounts for 34-42% by volume;

the prepared detection reagent is used for colorimetric detection of sucrose:

g. after a trace amount of sucrose is wiped by sampling paper, the detection reagent A is firstly dripped, then the reagent B is dripped on the filter paper containing a sucrose sample, and whether cherry red compound is generated or not is observed, so that the existence of the sucrose is determined.

The colorimetric reagent for rapidly detecting sucrose on site and the preparation method thereof provided by the invention realize detection by mainly utilizing the phenomenon that sucrose is catalyzed and dehydrated in binary ionic liquid to generate 5-hydroxymethylfurfural, and then the 5-hydroxymethylfurfural and barbituric acid-p-toluidine form a cherry red compound. The reagent has the advantages of easily obtained raw materials, simple and convenient preparation, no danger, strong selectivity, simple operation and wide application potential.

Detailed Description