阅读说明：本技术 一种污泥发酵耦合反硝化检测芥菜亚硝酸盐含量的方法 (Method for detecting nitrite content of mustard by sludge fermentation coupled denitrification ) 是由 余元善 徐玉娟 吴继军 温靖 傅曼琴 彭健 程丽娜 于 2020-07-10 设计创作，主要内容包括：本发明属于亚硝酸盐含量检测领域,尤其是一种污泥发酵耦合反硝化检测芥菜亚硝酸盐含量的方法,针对现有的亚硝酸盐与对氨基苯磺酸和N－1－萘基乙二胺混合后,需要人工摇晃均匀,加重了检测人员的劳动强度的问题,现提出如下方案,其包括以下步骤：S1：称取5-10g芥菜,然后剪碎作为样品,将样品放进容器内；S2：向容器内加入20-50ml蒸馏水,然后加热提取5-10min,加热温度为70-75℃,制得溶液,S3：将溶液投入反硝化反应器,投加污泥发酵上清液,缺氧搅拌反硝化,监测反应过程中pH值的变化曲线,本发明一次可以完成多个试管的摇匀工作,提高工作效率,节省人力,检测方法简单。(The invention belongs to the field of nitrite content detection, in particular to a method for detecting nitrite content in mustard by sludge fermentation coupling denitrification, aiming at the problems that after the existing nitrite is mixed with sulfanilic acid and N-1-naphthyl ethylenediamine, the manual shaking is required to be uniform, and the labor intensity of detection personnel is increased, the following scheme is proposed, and the method comprises the following steps: s1: weighing 5-10g of mustard, then cutting into pieces to be used as samples, and putting the samples into a container; s2: adding 20-50ml of distilled water into a container, heating and extracting for 5-10min at the temperature of 70-75 ℃ to obtain a solution, S3: the method has the advantages that the solution is put into a denitrification reactor, sludge fermentation supernatant is added, denitrification is carried out under anoxic stirring, and the change curve of the pH value in the reaction process is monitored.)

1. A method for detecting nitrite content in mustard by sludge fermentation coupled denitrification is characterized by comprising the following steps:

s1: weighing 5-10g of mustard, then cutting into pieces to be used as samples, and putting the samples into a container;

s2: adding 20-50ml distilled water into the container, heating and extracting for 5-10min at 70-75 deg.C to obtain solution;

s3: putting the solution into a denitrification reactor, adding sludge fermentation supernatant, carrying out anoxic stirring denitrification, monitoring a change curve of the pH value in the reaction process, stopping anoxic stirring in time to stop denitrification reaction after an inflection point appears in the process of pH value rising, precipitating, and draining to obtain a nitrite solution;

s4: measuring nitrite solution by using a test tube, dropwise adding aminobenzenesulfonic acid and N-1-naphthyl ethylenediamine into the test tube, uniformly shaking by using a shaking device to form red dye, and comparing the red dye with standard color developing solution to obtain the nitrite content of the mustard.

2. The method for detecting nitrite content in mustard by sludge fermentation coupling denitrification according to claim 1, wherein the shaking device comprises a base (1), a fixed seat (2) is fixedly installed at the top of the base (1), a rotating column (3) is rotatably installed at the top of the fixed seat (2), a rotating disc (4) is fixedly installed at the top of the rotating column (3), and a test tube rack (5) is arranged at the top of the rotating disc (4).

3. The method for detecting nitrite content in mustard by sludge fermentation coupling denitrification according to claim 2, wherein a mounting frame (12) is fixedly mounted at the top of the base (1), an air cylinder (13) is fixedly mounted at the top of the mounting frame (12), a bearing (14) is fixedly mounted on an output shaft of the air cylinder (13), a rotating shaft (15) is fixedly mounted on an inner ring of the bearing (14), and a cover plate (16) is fixedly mounted at the bottom of the rotating shaft (15).

4. The method for detecting nitrite content in mustard by sludge fermentation and denitrification in a coupling manner according to claim 2, wherein a clamping groove (7) is formed in the top of the turntable (4), a clamping block (6) is clamped in the clamping groove (7), and the top of the clamping block (6) is fixedly connected with the bottom of the test tube rack (5).

5. The method for detecting nitrite content in mustard by sludge fermentation coupling denitrification as claimed in claim 1, wherein a gear (8) is fixedly sleeved on the outer side of the rotating column (3), a mounting groove is formed in the top of the fixing seat (2), a motor (9) is fixedly mounted in the mounting groove, a circular plate (10) is fixedly mounted on an output shaft of the motor (9), two sets of teeth are fixedly connected to the outer side of the circular plate (10), a rack (11) is slidably mounted on the top of the fixing seat (2), the rack (11) is alternately meshed with the two sets of teeth, and the rack (11) is meshed with the gear (8).

6. The method for detecting nitrite content in mustard by sludge fermentation and denitrification in a coupling mode according to claim 1, wherein an operating table (17) is fixedly mounted on one side of the base (1), a controller (18) and a timer (19) are arranged on the top of the operating table (17), and the motor (9) and the timer (19) are both electrically connected with the controller (18).

7. The method for detecting nitrite content in mustard according to claim 1, wherein 30ml of distilled water is added into a container in S1, and then the solution is prepared by heating and extracting for 7min at 72 ℃.

8. The method for detecting nitrite content in mustard through sludge fermentation coupled denitrification as claimed in claim 1, wherein in S4, 2-7ml of nitrite solution is measured by a test tube, two drops of aminobenzenesulfonic acid and one drop of N-1-naphthylethylenediamine are added into the test tube, a shaking device is used for shaking uniformly to form red dye, and the red dye is compared with a standard developing solution to obtain the nitrite content in mustard.

Technical Field

The invention relates to the technical field of nitrite content detection, in particular to a method for detecting nitrite content of mustard by sludge fermentation coupled denitrification.

Background

Nitrite, a generic name for a class of inorganic compounds. Mainly means sodium nitrite, which is white to light yellow powder or granular, has slightly salty taste and is easy to dissolve in water. Nitrate and nitrite are widely present in human environment, are the most common nitrogen-containing compounds in nature, and nitrate in human body can be reduced into nitrite, precursor substance of N-nitroso compound under the action of microorganisms. The appearance and taste are similar to common salt, and the common salt is widely used in industry and building industry, and the meat product is allowed to be used as a color former in a limited amount. The chance of food poisoning by nitrite is high. When 0.3-0.5 g of nitrite is eaten, poisoning can be caused, and 3 g of nitrite causes death, so that the method is particularly important for detecting the content of the nitrite.

When the nitrite content is detected, usually, under the weak acid condition, the nitrite is diazotized with sulfanilic acid, then coupled with N-1-naphthyl ethylenediamine to form a mauve dye, and then compared with a standard color developing solution, but after the nitrite is mixed with sulfanilic acid and N-1-naphthyl ethylenediamine, the manual shaking is required to be uniform, and the labor intensity of detection personnel is increased, so that a method for detecting the nitrite content of mustard by sludge fermentation coupling denitrification is provided, and the problem is solved.

Disclosure of Invention

The invention aims to solve the defects that in the prior art, after nitrite is mixed with sulfanilic acid and N-1-naphthyl ethylenediamine, the nitrite needs to be uniformly shaken manually, and the labor intensity of detection personnel is increased, and provides a method for detecting the nitrite content of mustard by sludge fermentation coupled denitrification.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method for detecting nitrite content of mustard by sludge fermentation coupled denitrification comprises the following steps:

s1: weighing 5-10g of mustard, then cutting into pieces to be used as samples, and putting the samples into a container;

s2: adding 20-50ml distilled water into the container, heating and extracting for 5-10min at 70-75 deg.C to obtain solution;

s3: putting the solution into a denitrification reactor, adding sludge fermentation supernatant, carrying out anoxic stirring denitrification, monitoring a change curve of the pH value in the reaction process, stopping anoxic stirring in time to stop denitrification reaction after an inflection point appears in the process of pH value rising, precipitating, and draining to obtain a nitrite solution;

s4: measuring nitrite solution by using a test tube, dropwise adding aminobenzenesulfonic acid and N-1-naphthyl ethylenediamine into the test tube, uniformly shaking by using a shaking device to form red dye, and comparing the red dye with standard color developing solution to obtain the nitrite content of the mustard.

Preferably, the shaking device comprises a base, a fixing seat is fixedly mounted at the top of the base, a rotating column is rotatably mounted at the top of the fixing seat, a rotating disc is fixedly mounted at the top of the rotating column, and a test tube rack is arranged at the top of the rotating disc.

Preferably, the top fixed mounting of base has the mounting bracket, and the top fixed mounting of mounting bracket has the cylinder, and fixed mounting has the bearing on the output shaft of cylinder, and the inner circle fixed mounting of bearing has the axis of rotation, and the bottom fixed mounting of axis of rotation has the apron.

Preferably, the top of the rotary table is provided with a clamping groove, a clamping block is clamped in the clamping groove, and the top of the clamping block is fixedly connected with the bottom of the test tube rack.

Preferably, the fixed cover in the outside of rotating the post is equipped with the gear, and the mounting groove has been seted up at the top of fixing base, and fixed mounting has the motor in the mounting groove, and fixed mounting has the plectane on the output shaft of motor, two sets of teeth of outside fixedly connected with of plectane, and the top slidable mounting of fixing base has the rack, and rack and two sets of teeth mesh in turn, and rack and gear engagement.

Preferably, one side fixed mounting of base has the operation panel, and the top of operation panel is equipped with controller and time-recorder, motor, time-recorder all with controller electric connection.

Preferably, in the step S1, 30ml of distilled water is added into the container, and then the solution is prepared by heating and extracting for 7min at the heating temperature of 72 ℃.

Preferably, in S4, 2 to 7ml of nitrite solution is measured from a test tube, two drops of aminobenzenesulfonic acid and one drop of N-1-naphthyl ethylenediamine are added dropwise into the test tube, the test tube is shaken uniformly by using a shaking device to form a red dye, and the red dye is compared with a standard developing solution to obtain the nitrite content in the mustard.

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

according to the scheme, the test tubes to be uniformly shaken can be placed on the test tube rack through the arrangement of the shaking device, then the test tube rack is clamped on the rotary table, the solution in the test tubes is uniformly shaken through continuous forward and backward rotation of the rotary table, the shaking work of a plurality of test tubes can be completed at one time, the working efficiency is improved, and the labor is saved;

according to the scheme, the cover plate is arranged, so that a gate of a test tube needing to be shaken uniformly can be sealed, and liquid is prevented from being spilled;

the invention can complete the shaking-up work of a plurality of test tubes at one time, improves the working efficiency, saves the labor and has simple detection method.

Drawings

FIG. 1 is a schematic structural diagram of a shaking device of a method for detecting nitrite content in mustard by sludge fermentation coupled denitrification provided by the invention;

FIG. 2 is a schematic view of a top view structure of a rotating column, a gear, a turntable and a rack connection of the method for detecting nitrite content in mustard by sludge fermentation coupled denitrification provided by the invention.

In the figure: the device comprises a base 1, a fixing seat 2, a rotating column 3, a rotating disc 4, a test tube rack 5, a clamping block 6, a clamping groove 7, a gear 8, a motor 9, a circular plate 10, a rack 11, an installation frame 12, an air cylinder 13, a bearing 14, a rotating shaft 15, a cover plate 16, an operation table 17, a controller 18 and a timer 19.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.