CN102393466B - Primary amino radical tester - Google Patents

Abstract

The invention provides a primary amino acid measuring instrument mainly used for measuring the content of primary amino groups in proteins by improving the paradigm amino acid measuring instrument, which can be popularized and used for measuring the content of primary amino groups in various organic compounds. The device is mainly composed of a reaction part, a gas measuring part, a gas washing part and a recovery part, and has the characteristics of fast, accurate and clean.

Description

Primary Amino Tester

Technical field:

The invention belongs to the field of chemical analysis testing instruments and equipment, and relates to an instrument mainly used for measuring the content of primary amino groups in proteins (including collagen polypeptides and various amino acids)—a primary amino group measuring instrument.

Background technique:

The methods currently used to measure the content of primary amino groups in proteins include ninhydrin colorimetry, TNBS colorimetry, micellar electrokinetic chromatography, formaldehyde method, Van Slyck method, and gas chromatography. Among them, ninhydrin colorimetry and TNBS colorimetry belong to spectrophotometric methods, and both have instrument errors. In addition, in the ninhydrin colorimetric method, the length of time for heating the color and the depth of the color after color development will cause errors; the TNBS colorimetric method is very specific, mainly reacting with the ε-amino group of lysine, and cannot Quantitation of all primary amino groups. In the formaldehyde method, the methylol compound also has a side reaction of further condensation with the primary amino group, which affects the measurement accuracy. In addition, formaldehyde is easily oxidized to formic acid due to the influence of the external environment during storage, and formic acid will consume additional sodium hydroxide during the titration process, resulting in high measurement results. Although chromatography has high sensitivity, it has high requirements on instruments and equipment, for example, the stainless steel reaction device required in gas chromatography has high processing requirements and is expensive. During the use of the Van Slyck method, the measurement cycle is long, the experimental operation is complicated, and the experiment is greatly affected by the external environment temperature.

The existing Paradigm amino acid analyzer is mainly composed of three parts: a reaction device, a gas measuring device and a gas scrubbing device. Wherein the reaction device and the gas washing device are respectively integrated structures, which bring a lot of inconvenience to cleaning. The original Paradigm Amino Acid Analyzer needs a special bracket for fixing, which takes up a lot of space. The test is greatly affected by the surrounding environment, and it cannot be measured at low temperatures. The Paradigm Amino Acid Analyzer does not conduct unified treatment of waste gas and waste liquid, which seriously pollutes the environment.

Invention content:

Aiming at the deficiencies of the prior art, the object of the present invention is to provide a primary amino acid analyzer and its usage method.

The invention is based on the Van Slyck method and on the basis of the Paradigm amino acid measuring instrument, and designs a fast, simple, accurate and clean primary amino acid measuring instrument. The reaction part (I) of the analyzer contains a magneton (9), with a water bath jacket (4) and magnetic stirring (10), and the bottom of the reactor (1) is designed as a flat bottom. The gas washing part (III) of the measuring instrument contains a magneton (29) and is equipped with a magnetic stirrer (30), and the bottom of the gas washing hemisphere (27) is a flat bottom design. The device can be used for the measurement of primary amino groups in protein, gelatin and trace amino acids.

A kind of primary amino measuring instrument, is made up of reaction device (I), gas measuring device (II), scrubbing device (III), recovery device (IV), is characterized in that, reaction device (I), gas measuring device (II ), the gas scrubber (III), and the recovery unit (IV) are connected in sequence, and the exhaust ports and liquid outlets of the reaction device (I), the gas measuring device (II), and the gas scrubber (III) are all connected to the recovery part ( IV) on.

Preferably, the reaction device (I) comprises a reactor (1), a feeding pipe (2) and a three-way connecting pipe (14). Preferably, the three-way connecting pipe (14) is equipped with a cock (15), and the cock (15) is located at the junction of the three-way connecting pipe (14) for adjusting the direction of gas in the three-way connecting pipe (14).

Preferably, the upper part of the reactor (1) is a grinding port (12), and the bottom is a flat bottom with a water bath jacket (4), as shown in FIG. 1 . The bottom of the reactor (1) has an upward narrow-necked glass tube (7) and a downward discharge tube (11); one end of the narrow-necked glass tube (7) is connected to the feeding tube (2), and the other end passes through the jacket (4) is connected with the inner wall of the reactor (5); the discharge pipe (11) is connected with the inner wall of the reactor (5) through the jacket (4), and is used for discharging of the reactor (1). Preferably, two ports (6) are provided on the outer wall of the reactor jacket (4) for communicating with the circulating water bath. Preferably, the reactor (1) contains a magnet (9), and the bottom is equipped with a magnetic stirring (10).

Preferably, the reaction device (I) includes two feed pipes—the first feed pipe (2) and the second feed pipe (3). Preferably, the lower parts of the first feeding tube (2) and the second feeding tube (3) are narrow-necked glass tubes, the first feeding tube (2) is 25-35ml, and the second feeding tube (3) is about 10-20ml. Reactor (1) comprises two narrow-necked glass tubes, the first narrow-necked glass tube (7) and the second narrow-necked glass tube (8), respectively connecting the first feed pipe (2) and the second feed pipe (3) .

Preferably, the three-way connecting pipe (15) is connected with the ground port (12) on the upper part of the reactor through the ground plug (13) at one end of the narrow-necked glass tube, and the other end of the three-way connecting pipe (15) passes through the narrow-necked elbow ( 17) link to each other with inclined hole three-way piston (19).

Gas scrubbing device (III) includes gas scrubbing hemisphere (27) and buffer ball (26); gas scrubbing hemisphere (27) and buffer ball (26) pass through narrow neck glass connecting pipe (23) and oblique hole three-way piston (19) connect. Preferably, the air washing hemisphere (27) has a radius of 100-150 mm, and the buffer ball (26) has a radius of 80-100 mm.

Preferably, the top of the gas washing hemisphere (27) is connected with a narrow-necked glass tube (24) for gas entry and exit; the bottom has a downward glass tube (25) for liquid drainage, and has a 90 ° upward bend (28) is used for connecting buffer ball (26). The air-washing hemisphere (27) is flat-bottomed, contains magnets (29), and is equipped with a magnetic stirrer (30).

The recovery device (IV) comprises a four-way connecting pipe (31) and a recovery bottle (33). Preferably, the recovery bottle (33) is equipped with a rubber stopper (36) containing two glass tubes (34), (35).

The reactor (1) of the present invention is equipped with a water bath jacket (4), the bottom end is connected with two feeding pipes, the first feeding pipe (2) and the second feeding pipe (3), and the upper grinding port (12) passes through the narrow neck glass The ground plug (13) at one end of the pipe is connected with the three-way connecting pipe (14), and the other end of the three-way connecting pipe (14) is connected with the oblique hole three-way piston (19) through a narrow neck bend (17), and the gas measuring pipe ( 20) The lower part is connected to the level ball (21) through the latex tube (22) (the length of the latex tube (22) is 1.5 times that of the trachea (20)), and the upper straight tube (18) of the trachea (20) passes through the connecting tube (23) Connect the gas washing hemisphere (27), and the gas washing hemisphere (27) lower end 90 ° upward elbow (25) connects the buffer ball (26). Three-way connection pipe exhaust pipe (16), reactor drain pipe (11), and gas washing hemispherical drain pipe (25) all pass through the silicone tube (the silicone tube on the drain pipe (11), (25) mouth There is a water stop clamp) to be connected with the four-way connecting pipe (31), and then connected to the recovery device (IV) through a silicone tube (32).

The water-bath jacket (4) of the reactor (1) of the present invention is connected with a constant temperature water bath to adjust the reaction temperature; the reactor (1) contains a magnet (9), and the bottom is equipped with a magnetic stirrer (10). The stirring speed can adjust the reaction speed. The air-washing hemisphere (27) of the present invention contains magnets (29), and the lower part is equipped with a magnetic stirring (30), and the air-washing speed is adjusted by adjusting the stirring speed.

The present invention also provides the using method of described primary ammonia quantifier, comprises the following steps:

Before the use of the present invention, preparatory work is carried out, each interface is sealed, and the reactor drain pipe (11) and the gas washing hemispherical drain pipe (25) are clamped with water-stop clips. First inject deionized water from the level ball (21), after filling the trachea (20) with deionized water, turn the trachea cock to keep the trachea (20) full of water. Then pour the scrubbing liquid (20-40g potassium permanganate, 20-40g sodium hydroxide, 200-400ml deionized water) from the buffer bottle (26), fill the scrubbing hemisphere (27) to the cock of the measuring tube When at (19), turn the trachea cock (19) so that the trachea (20) communicates with the three-way connecting pipe (14). Raise the level ball (21), and fill the measuring gas pipe (20) with deionized water to the three-way connecting pipe cock (15). Turn the three-way connecting pipe cock (15) so that the reactor (1) communicates with the recovery device (IV) through the three-way connecting pipe exhaust pipe (11), and at the same time turn the measuring air pipe cock (19) to the horizontal direction, and close the volume trachea. Put the level ball (21) in a low place, and now the air-washing hemisphere (27) and the gas measuring tube (20) are all full of liquid, and are isolated from the outside air. Turn on the circulating water bath with magnetic stirring (10).

The present invention adds about 20～30ml of glacial acetic acid earlier from the first feeding pipe (2) during sample testing, then adds about 20～30ml of 40% sodium nitrite aqueous solution, closes the first feeding pipe (2) and the second feeding pipe ( 3). React in the reactor (1) to generate NO or NO ₂ gas, keep it for 5-8 minutes, and exhaust the air in the reactor (1). Turn the three-way connecting pipe cock (15) to close the reactor (1). Open the first feeding pipe (2) and the second feeding pipe (3), gas is generated in the reactor (1) and the liquid is driven out from the first feeding pipe (2) and the second feeding pipe (3), when the second After the gas in the lower narrow neck of the first feed pipe (2) and the second feed pipe (3) is completely driven out, the first feed pipe (2) and the second feed pipe (3) are closed. Rotate the three-way connecting pipe cock (15) and the burr cock (19), so that the reactor (1) is only communicated with the burr (20), so that the gas in the reactor (1) enters the burr (20). Fill the first feed pipe (2) with deionized water and seal it with liquid. Add the protein solution to be tested in the second feeding pipe (3), slowly open the cock of the feeding pipe (3), so that the liquid to be tested slowly flows into the reactor (1), and rinse the second feeding pipe (3) with a small amount of deionized water, Seal with n-pentanol. Close the second feed tube (3) at the end of the feed. During the reaction process, when the gas in the trachea (20) exceeds the thin neck part of the trachea, the level ball (21) is raised rapidly, and the trachea cock (19) is rotated to drive the gas into the wash hemisphere (27). After the gas is driven away, turn the trachea cock (19) to close the gas washing hemisphere (27), so that the trachea (20) communicates with the reactor (1). Put the level ball (21) at a low place, and continue to keep the gas in the reactor (1) entering the burette (20). The reactor (1) starts timing the reaction for 30 minutes to 60 minutes from the time of adding the test solution, and stops the reaction. Open the first feeding pipe (2) and the second feeding pipe (3) respectively, so that the liquid in the first feeding pipe (2) and the second feeding pipe (3) enters the reactor (1). After driving away the gas in the reactor (1), turn the trachea cock (19) to close the trachea (20). Open the water stop clip of the reactor drain port (11), so that the reaction waste liquid all flows into the recovery bottle (33). Lift the level ball (21), turn the trachea cock (19), and all the gas is driven into the gas washing hemisphere (27). Turn the burette cock (19) to close the burette (20). Turn on the stirring speed of the magneton (29) in the gas washing hemisphere (27) and keep it for 2-5 minutes. Stop the magnetic stirring (30) of the gas washing hemisphere (27), turn the upper cock (19) of the gas washing tube, lower the level ball (21), and drive the gas in the gas washing hemisphere (27) into the gas measuring tube (20). When the gas-liquid flows to the trachea cock (19), turn the trachea cock (19) to close the trachea (20). Raise the level ball (21), make the level of the liquid level in the level ball (21) and the liquid level in the gas tube (20), read the scale of the gas tube (20), record the volume V, and record the air pressure and temperature at the same time, for later calculations.

Compared with prior art, the present invention has the following advantages:

1. The reaction is not affected by changes in external environmental conditions. Compared with the Paradigm Amino Acid Analyzer, it can be measured at low temperature in winter. The measurement data is stable, and the average error is reduced by half compared with the standard amino acid analyzer.

2. The reaction temperature can be adjusted through the circulating water bath, the detection cycle is short, and the reaction time is shortened by 1/3 compared with the normal amino acid analyzer.

3. The air washing hemisphere (27) is equipped with a magnetic stirring (10), which can automatically wash air. The reactor (1) is equipped with a magnetic stirring (30), which can fully carry out the reaction and adjust the reaction process.

4. Easy to clean, each part can be disassembled and cleaned separately, and the reactor (1) and the gas washing hemisphere (27) can be passed through the magnetic stirring (10) of the reactor (1) and the agitator of the gas washing hemisphere (27) (30) Carry out self-cleaning.

5. The addition of recovery part (IV) makes the reaction process cleaner, and the reaction waste liquid (mixture of sodium nitrite, glacial acetic acid and liquid to be tested) and scrubbing waste liquid (mixture of potassium permanganate and sodium hydroxide) It can be directly discharged into the recovery bottle through the silicone tube (32), and the waste liquid can react with each other and self-clean, and the waste gas generated by the reaction is uniformly discharged through the recovery part (IV) to keep the environment clean.

6. It is small in size and easy to place. Except for the recovery device (IV), it can be placed on the test bench for operation.

Description of drawings:

Fig. 1 schematic diagram of the primary amino group measuring instrument of the present invention. in:

1. Reactor 2, first feeding pipe 3, second feeding pipe 4, water bath jacket 5, reactor inner wall 6, circulating water bath interface 7, first thin neck feeding pipe 8, second thin neck feeding pipe 9 , magnet 10, magnetic stirring 11, drain pipe 12, reactor grinding mouth 13, grinding mouth plug 14, three-way connection pipe 15, three-way cock 16, exhaust pipe 17, thin neck elbow 18, thin neck straight Pipe 19, oblique hole three-way piston 20, measuring gas pipe 21, level ball 22, latex pipe 23, thin neck connecting pipe 24, thin neck buffer pipe 25, drain pipe 26, buffer ball 27, gas washing hemisphere 28, liquid inlet Tube 29, magnet 30, magnetic stirring 31, four-way connecting tube 32, silicone tube 33, recovery bottle 34, liquid inlet tube 35, exhaust tube 36, rubber plug

Specific implementation plan:

The following examples are further illustrations of the present invention, but the present invention is not limited thereto.

Example 1

The primary amino acid measuring instrument of the present invention is composed of a reaction device (I), a gas measuring device (II), a gas washing device (III), and a recovery device (IV).

Preferably, the reaction device (I) includes a reactor (1), a first feeding pipe (2), a second feeding pipe (3) and a tee connecting pipe (14). Wherein the reactor contains a water bath jacket (4), and the outer wall of the water bath jacket (4) contains two interfaces (6) for connecting a circulating water bath. Preferably, the bottom of the reactor is a flat bottom, containing a first narrow-necked glass tube (7), a second narrow-necked glass tube (8) and a downward discharge tube (11). One end of the first thin-necked glass tube (7) is connected to the first feed pipe (2), and the other end passes through the water bath jacket (4) and is connected with the inner wall of the reactor (5) for adding the reaction solution; One end of the neck glass tube (8) is connected to the second feed pipe (3), and the other end passes through the water bath jacket (4) to connect with the inner wall of the reactor (5) for adding the liquid to be tested; the discharge pipe (11) It passes through the water bath jacket (4) and connects with the inner wall of the reactor (5) for discharge of the reactor (1). The discharge pipe (11) is connected with the four-way connection pipe (31) in the recovery device (IV) through a silicone tube, and the discharge pipe (11) is equipped with a water stop clip. Preferably, the reactor (1) contains a magnet (9), and the bottom is equipped with a magnetic stirring (10). The upper part of the reactor (1) is a grinding port (12), which is connected with the grinding port piston of the three-way connecting pipe. The glass tubes of the three-way connecting pipe (14) are thin-necked glass tubes, and the intersection is a three-hole cock (15). One end (13) with a ground plug in the three ends of the three-way connecting pipe is connected to the reactor grinding port (12), and one end of the exhaust port (16) is connected to the four-way connecting pipe in the recovery device (IV) through a silicone tube. (31) connects, and the last end links to each other with inclined hole three-way piston (19) by thin neck elbow (17).

Preferably, the gas measuring device (II) includes a gas measuring tube (20) and a level ball (21). The upper end of the gas measuring tube contains a three-way cock (19) with oblique holes, and the upper end of the cock is two thin-necked glass tubes; the elbow (17) is connected to the three-way connecting pipe, and the straight thin-necked pipe (18) passes through the gas washing device (III) The thin neck connecting pipe (23) in the middle is connected with the gas washing hemisphere (27). Preferably, the thin neck in the gas measuring tube is divided into a gas measuring part, the scale range is 10-15ml, and the minimum scale is 0.05ml; out), the volume of the buffer part is about 150-200ml, and the bottom contains an interface, which is connected with the level ball (21) through a latex tube. Preferably, the level ball has a volume of about 200-250ml and is placed at a low place.

Preferably, the gas washing device (III) includes a thin-necked connecting pipe (23), a gas washing hemisphere (27) and a buffer ball (26). Wherein one end of the thin-necked connecting pipe is connected with the gas measuring tube (20) through the thin-necked straight pipe (18), and the other end is connected with the gas washing hemisphere (27) through the buffer pipe (24). Preferably, the air-washing hemisphere (27) is flat-bottomed, with a radius of about 100-150 mm, contains magnets (29), and is equipped with a magnetic stirrer (30). The bottom of the scrubbing hemisphere contains two glass tubes, of which the downward sloping one is the drain pipe (25), which is used to discharge the scrubbing liquid, and is connected to the four-way connecting tube (31) in the recovery device (IV) through a silicone tube ; 90 ° upward elbow (28) is connected with the buffer ball (26) lower end. Preferably, the radius of the buffer ball (26) is about 80-120 mm, and the upper part is a funnel-shaped liquid inlet with a diameter of about 50-70 mm, which is convenient for adding the washing liquid.

Preferably, the recovery device (IV) includes a four-way connecting pipe (31) and a recovery bottle (33). Wherein the three interfaces at one end of the four-way connection pipe (31) are respectively connected to the exhaust port (16), the reactor liquid outlet (11) and the gas washing hemispherical liquid outlet (25), and the interface at the other end is connected to the inlet port through a silicone tube. Liquid pipe (34) is connected. Preferably, the recovery bottle (33) has a volume of 10-20L, which is used for the recovery and storage of the reaction waste liquid; the recovery bottle (33) is equipped with a rubber stopper (36) at the top, and the rubber stopper contains a feed pipe (34) and Air outlet pipe (35), air outlet pipe (35) is directly connected in exhaust hood or fume hood air outlet by silicone tube, prevents gas from escaping.

The primary amino acid analyzer of the present invention, its reaction device (I), gas measuring device (II), and gas washing device (III) can be placed on the test bench and fixed with an iron stand. The recovery unit (IV) is placed at a place where the horizontal position is lower than the reaction unit (I) and the gas scrubber (III), and it can be processed at any time.

Example 2

1. Experimental preparation:

When the present invention is used, the preparatory work is first carried out. At first, the gas washing liquid (20-40 g of potassium permanganate, 20-40 g of sodium hydroxide, 200-400 ml of deionized water) will be prepared, and then each piston is wiped with vacuum grease, and the reaction The upper port (12) of the device is wrapped with a sealing film and fixed with clips, the reactor drain pipe (11) and the gas washing hemispherical drain pipe (25) are clamped with water-stop clips, and the reactor jacket (4) communicates with the circulating water bath . The three-way connecting pipe cock (15) is screwed into The trachea cock (19) is screwed into "\\" (as shown in Fig. 1, the trachea cock (19)), to ensure that the trachea (20) communicates with the recovery device (IV) by the three-way connecting pipe exhaust pipe (11). Inject deionized water from the level ball (21), raise the level ball (21) (higher than the gas tube cock (19)), drive the gas out from the exhaust pipe (11) of the three-way connecting pipe, and remove the gas tube (20) After filling with deionized water, turn the trachea cock (19) 90° to be horizontal, close the trachea (20), and keep the trachea (20) full of water. Finally, pour the gas washing liquid from the buffer bottle (26) into the half bottle of washing gas (27), turn the cock (19) on the measuring trachea into "//", keep the measuring trachea (20) in communication with the washing hemisphere (27), Lower the level ball (21), suck the gas in the gas washing hemisphere (27) into the trachea (20), when the gas washing liquid flows to the cock (19) of the trachea (make sure that there is no gas in the drain port (25)) . Turn the trachea cock (19) 180 ° into "\\", make the trachea (20) and the wash hemisphere (27) closed, and communicate with the three-way connecting pipe (14). Raise the level ball (21), drive the gas out from the exhaust pipe (11) of the three-way connecting pipe, and fill the gas measuring tube (20) with deionized water (the three-way tube (14) is connected with the gas measuring tube (20) with a thin neck There is no gas remaining inside), turn the burette cock (19) to the horizontal direction, and close the burette (20). Turn the three-way connecting pipe cock (15) 180° into The reactor (1) communicates with the recovery device (IV) through a three-way connecting pipe exhaust pipe (11). Put the level ball (21) in a low place, and now the air-washing hemisphere (27) and the gas measuring tube (20) are all full of liquid, and are isolated from the outside air. Turn on the circulating water bath and the magnetic stirring (10) (in the horizontal experiment, the temperature of the circulating water bath is constant, and the rotating speed of the magnetic stirring (10) under the reactor (1) is constant).

2. Test samples:

The present invention first adds about 20～30ml of glacial acetic acid from the first feeding pipe (2) during sample testing, then adds about 20～30ml of 40% sodium nitrite aqueous solution (the liquid in the reactor (1) reaches more than 3/4 of the reactor ), turn the first feeding pipe (2) and the second feeding pipe (3) cocks, the first feeding pipe (2) and the second feeding pipe (3) are closed, and the reactor (1) only passes through the three-way connecting pipe Exhaust pipe (11) links to each other with recovery device (IV). React in the reactor (1) to generate NO or NO ₂ gas, and keep it for more than 2-5 minutes to ensure that all the air in the reactor (1) is exhausted. Turn the three-way connecting pipe cock (15) into The reactor (1) is sealed, and the burette (20) is not communicated with the outside world at the same time. Rotate the cocks of the first feed pipe (2) and the second feed pipe (3), so that the first feed pipe (2) and the second feed pipe (3) are opened, and gas is generated in the reactor (1) to remove the liquid from the first The feeding pipe (2) and the second feeding pipe (3) are driven out. After the gas in the lower part of the first feeding pipe (2) and the second feeding pipe (3) is completely driven out, turn the first feeding pipe ( 2) and the second feed pipe (3) cock, the first feed pipe (2) and the second feed pipe (3) are closed. Turn the trachea cock cock (19) into "\\", so that the reactor (1) is only communicated with the trachea (20) and isolated from the outside world, so that the gas in the reactor (1) enters the trachea (20) (at this time The gas in the reactor (1) and the measuring gas tube (20) is only the NO or _NO gas produced by the reaction). Add deionized water (accounting for 3/4 of the volume, acting as a liquid seal, and preparing for the back of the experiment) into the feed pipe (2). Add the protein solution to be tested into the second feeding tube (3) (if necessary, please heat to keep the protein solution as a flowing liquid), slowly open the cock of the second feeding tube (3), so that the test solution slowly enters the reactor (1) (Do not overdos, leave a trace to prevent air from entering the reactor (1)). Close the cock of the second feeding tube (3), rinse the second feeding tube (3) (5ml-10ml) with a small amount of deionized water, and then add about 1-2ml of n-amyl alcohol (n-amyl alcohol and the solution are layered and placed above the solution) ), slowly open the second feeding pipe (3) cock, so that the solution slowly enters the reactor (1), close the cock when n-amyl alcohol reaches the second feeding pipe (3) cock, add deionized water (accounting for volume 3/ 4. It acts as a liquid seal and prepares for the experiment later). During the reaction, when the gas in the trachea (20) exceeds the thin neck of the trachea, quickly raise the level ball (21), turn the cock of the trachea (19) 180° into "//", keep the trachea (20) and The gas washing hemispheres (27) communicate with each other to drive the gas into the gas washing hemispheres (27) (turn on the magnetic stirring (9) below the gas washing hemispheres (27) to make NO and _NO gas quickly absorbed by the gas washing liquid), equivalent to the trachea After the gas in (20) is driven out, turn the measuring gas pipe cock (19) 180° into "\\", so that the measuring gas pipe (20) is closed with the gas washing hemisphere (27), and communicates with the reactor (1), and the Level ball (21) is put on low place, continues to keep the gas in reactor (10) to enter burette (20). The reactor (1) starts timing reaction for 30-60 minutes after adding the liquid to be tested (the gas needs to be driven into the gas washing hemisphere (27) several times in the process), and the reaction is stopped. Open the first feed pipe (2) and the second feed pipe (3) cocks respectively, so that the liquid in the first feed pipe (2) and the second feed pipe (3) enters the reactor (1), and the first feed pipe (2) and the air in the lower narrow neck of the second feed pipe (3) rush into the reactor (1), close the cock of the second feed pipe (3), and keep the cock of the first feed pipe (2) open. As the liquid is continuously added, the gas in the reactor (1) is all rushed into the gas tube (20). When liquid rushed to the three-way connection pipe cock (15) place, turn the trachea cock (19) 90 ° into a horizontal direction, close the trachea (20), and close the first feeding pipe (2) cock simultaneously. Turn the three-way connecting pipe cock (15) into Open the water stop clip of the reactor drain port (11), so that the reaction waste liquid all flows into the recovery bottle (33). Close the water stop clamp, open the cock of the first feeding pipe (2), add deionized water until the reactor (1) is full, close the cock of the first feeding pipe (2), and automatically clean the reactor (1) with magnetic stirring (10) (keep the opening of reactor (1) circulating water bath and magnetic stirring (10) during the reaction process). Lift the level ball (21), turn the volume trachea cock (19) into "//", and all the gas is driven into the gas washing hemisphere (27) (the narrow neck tube (24) has no gas residue on the gas washing hemisphere (27)), Rotate the trachea cock (19) 90° into a horizontal direction, and close the trachea (20). Turn on the stirring speed of the magneton (29) in the gas washing hemisphere (27) and keep it for 2-5 minutes. Stop the magnetic stirring (30) of the gas washing hemisphere (27), turn the upper cock (19) of the measuring trachea into "//", keep the measuring trachea (20) communicating with the gas washing hemisphere (27), lower the level ball (21) , suck the gas in the gas washing hemisphere (27) into the measuring trachea (20), when the washing liquid flows to the measuring trachea cock (19), turn the measuring trachea cock (19) 90° into a horizontal direction, close the measuring trachea (20 ). Raise the level ball (21), make the level of the liquid level in the level ball (21) and the liquid level in the gas tube (20), read the scale of the gas tube (20), record the volume V, and record the air pressure and temperature at the same time, for later calculations.

3. Post-experiment processing:

Turn the measuring trachea cock (19) into "\\", turn the three-way connection pipe cock (15) into Keep the trachea (20) connected to the recovery device (IV) through a three-way connecting pipe exhaust pipe (16). Lift the level ball (21), drive the gas out from the exhaust pipe (16) of the three-way connecting pipe, fill the measuring gas pipe (20) with deionized water, turn the measuring gas pipe cock (19) 90° to a horizontal direction, and close the volume Trachea (20), keep measuring gas tube (20) and be full of water state (there is no gas residue in the narrow neck glass tube between three-way cock (15) and oblique hole three-way cock (19)). Turn the three-way connecting pipe cock (19) into The measuring gas pipe (20) is closed with the three-way connection pipe (14), and the reactor (1) communicates with the recovery device (IV) through the three-way connection pipe exhaust pipe (16). Put the level ball (21) at a low place, open the water stop clamp of the reactor drain port (11), drain the liquid in the reactor (1), close the water stop clamp of the liquid drain port (11), and prepare for the next test kind of test. During the sampling process, when the gas washing liquid changes from dark purple to dark blue, open the water stop clip of the liquid discharge port (25) to drain the liquid of the gas washing hemisphere (27). Close the water stop clip of the drain port (25), and add new washing liquid. After the test reaction is all finished, open the reactor drain port (11) and the gas washing hemisphere drain port (25) water stop clamp, and drain the waste liquid in the reactor (1) and the gas washing hemisphere (27). Add the mixed solution of glacial acetic acid and sodium nitrite from the buffer ball (26) into the air washing hemisphere (27), turn on the magneton (29) rotating speed in the air washing hemisphere (27), and wash off the Scrubbing fluid remains. After draining the waste liquid, wash it again with deionized water. Inside the recovery unit (IV) is the mixed liquid of potassium permanganate, sodium hydroxide, glacial acetic acid and sodium nitrite discharged from the reactor (1) and the gas scrubbing hemisphere (27), which reacts and absorbs each other. The produced NO and NO ₂ gases are uniformly discharged through the exhaust port (35) for treatment. If the sample to be tested tends to generate a lot of bubbles, a small amount of n-amyl alcohol should be added to the reactor (1) for defoaming before adding the liquid to be tested.

4. Calculate

The following formula gives the calculation formula of the primary amino test instrument and the setting method of related parameters.

Note that n _sample is the molar amount of the primary amino group of the sample, and n _N2 is the molar amount of the measured nitrogen gas. From the reaction principle, it can be known that the molar ratio of the primary amino group reaction to generate nitrogen gas is 1:1, then this equation can be expressed as:

n _sample = n _N2 (1)

Note that c is the molar content of the sample (mol/g), and m is the sample mass (m), then the equation can be expressed as:

n _sample = c m (2)

Note that ρ is the mass density of nitrogen (g/ml), which is obtained according to the external temperature and atmospheric pressure when measuring gas, V is the volume of nitrogen measured (ml), and M is the molecular weight of nitrogen (mol/g), then the equation can be expressed as :

n _N2 = ρV/M (3)

Put the formulas (2), (3) into (1), and sort them out to get:

$\mathrm{<span\; class="notranslate">\; c</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; V</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

The primary amino group content of the sample can be calculated by formula (4).

Claims (6)

1. A primary amino measuring instrument is made up of reaction device (I), gas measuring device (II), scrubber (Ⅲ), recovery device (IV), reaction device (I), gas measuring device (II), Gas scrubbing device (Ⅲ) and recovery device (Ⅳ) are connected sequentially, and it is characterized in that described reaction device (I) comprises reactor (1), feeding pipe (2) and three-way connection pipe (14), wherein reaction The upper part of the device (1) is a grinding mouth (12), the inside contains magnets (9), the bottom is flat and equipped with magnetic stirring (10), and the outside is equipped with a water bath jacket (4); the gas scrubber (Ⅲ) includes a gas scrubber Hemisphere (27) and buffer ball (26), wherein the air washing hemisphere (27) has a flat bottom, contains magnets (29), and is equipped with a magnetic stirrer (30); the recovery device (IV) includes a four-way connecting pipe (31) With recovery bottle (33), the outlet of reaction device (I), measuring gas device (II), gas scrubber (III) and the drain port are all connected on the recovery device (IV). 2. primary amino measuring instrument as claimed in claim 1, is characterized in that, comprises the first feed pipe (2) and the second feed pipe (3) in the described reaction unit (I), wherein the first feed pipe ( The bottom of 2) is connected with the first narrow-necked glass tube (7), and the bottom of the second feeding tube (3) is connected with the second narrow-necked glass tube (8). The volume of the first feeding tube (2) is 25～35ml, and the second The volume of the two feeding tubes (3) is 10-20ml. 3. the primary amino measuring instrument as claimed in claim 1, is characterized in that, there is an upward narrow-necked glass tube (7) and a downward row of glass tubes (7) at the bottom of the reactor (1) in the described reaction device (I). Feed pipe (11), one end of the thin-necked glass pipe (7) is connected to the feed pipe (2), and the other end passes through the jacket (4) to connect with the inner wall of the reactor (5); the discharge pipe (11) passes through the jacket The sleeve (4) is connected with the inner wall (5) of the reactor for the discharge of the reactor (1); the outer wall of the jacket (4) of the reactor contains two interfaces (6) for communicating with the circulating water bath. 4. primary amino measuring instrument as claimed in claim 1, is characterized in that, in described reaction device (I), tee connecting pipe (14) passes through the ground plug (13) of one end of narrow-necked glass tube and reactor The upper grinding mouth (12) is connected, and the other end of the three-way connecting pipe (14) is connected with the oblique hole three-way piston (19) through a narrow neck bend (17), wherein the three-way connecting pipe (14) has a cock (15 ), the cock (15) is positioned at the junction of the three-way connecting pipe (14), and is used for regulating the direction of gas in the three-way connecting pipe (14). 5. the primary amino measuring instrument as claimed in claim 1, is characterized in that, the air washing hemisphere (27) and the buffer ball (26) are connected with the inclined hole three-way piston (19) through the narrow neck glass connecting pipe (23); The top of the gas washing hemisphere (27) is connected with a thin-necked glass tube (24) for gas entry and exit; the bottom has a downward glass tube (25) for liquid drainage, and has a 90° upward bend (28 ) is used to connect the buffer ball (26); the radius of the air washing hemisphere (27) is 100-150 mm, and the radius of the buffer ball (26) is 80-100 mm. 6. the using method of primary amino measuring instrument as claimed in claim 1, comprises the following steps: 1) Preparatory work: prepare the washing liquid, fill the washing hemisphere (27), then fill the gas washing tube (20) with deionized water, and keep the washing hemisphere (27) and the gas washing tube (20) full of liquid , isolated from the outside air, wherein the main components of the washing liquid include potassium permanganate 20-40g, sodium hydroxide 20-40g, deionized water 200-400ml; open the circulating water bath and magnetic stirring (10); 2) sample measurement: add glacial acetic acid 20～30ml to the first charging pipe (2) successively, 40% sodium nitrite aqueous solution 20～30ml, chemical reaction takes place in the reactor (1), generates NO or _NO gas, Drain the air in the reactor (1); drive out the gas in the thin neck of the first feeding pipe (2) and the lower part of the second feeding pipe (3), and keep the reactor (1) only communicated with the measuring gas pipe (20) by adjusting the cock , isolated from the outside atmosphere; add the protein solution to be tested into the second feeding tube (3), seal it with n-amyl alcohol liquid, stop the reaction after 30-60 minutes, and the gas produced is rushed into the gas washing hemisphere from the gas measuring tube (20) (27), turn on magnetic stirring, absorb NO ₂ gas, after 10～30 minutes, drive the remaining gas into the gas tube (20), read the scale of the gas tube (20), record the volume V, and record the air pressure and temperature at this time.