CN118454653A - A grapefruit peel adsorbent and its preparation method and application - Google Patents

Abstract

The present invention relates to the field of chemical technology, and in particular to a grapefruit peel adsorbent and a preparation method and application thereof. The preparation method of the grapefruit peel adsorbent comprises the following steps: boiling grapefruit peel; rinsing the boiled grapefruit peel to neutrality; soaking the neutralized grapefruit peel in a 0.1-0.5 mol/L calcium chloride solution, and then ultrasonicating at a temperature of 65-75°C and a power of 60-70 Hz; rinsing the ultrasonicated grapefruit peel again to neutrality and drying; finally, crushing the dried grapefruit peel and filtering it with an 8-80 mesh sieve to obtain the grapefruit peel adsorbent. The grapefruit peel adsorbent of the present invention has good adsorption performance for nicotine, can adsorb nicotine in smoke, reduce its harm to the human body and pollution to the environment, and has broad application prospects.

Description

A grapefruit peel adsorbent and its preparation method and application

Technical Field

The invention relates to the technical field of chemistry, and in particular to a grapefruit peel adsorbent and a preparation method and application thereof.

Background Art

Nicotine, also known as nicotine, is an addictive chemical. Nicotine has a pungent smell and is a colorless oily liquid. It is highly volatile and easily turns brown in the air. It is easily soluble in water and organic solvents. Nicotine can damage many organs of the human body and cause cancer, hypertension, chronic bronchitis and other lung diseases. Studies have shown that only a few milligrams of pure nicotine are needed to cause headaches, loss of consciousness, etc., so people who smoke too much will suffer from chronic poisoning. The harm of nicotine to the human body is not only manifested in the addiction of people, but also can cause smoke-induced optic neuropathy. Long-term smoking can cause vision loss, severe cases can cause optic atrophy, and eventually blindness. Therefore, it is necessary to develop a product that can reduce the amount of nicotine inhaled by smokers in cigarettes.

At present, most of the cigarettes sold on the market rely solely on ordinary acetate fiber to further reduce nicotine in smoke. Acetate fiber has the advantages of good taste absorption effect, beautiful appearance, good hardness, etc., but its production is complex and slow, the cost is high, and the adsorption effect of nicotine in cigarettes is poor; the carbon content of activated carbon is as high as over 90%. It is a non-toxic and tasteless porous substance with good adsorption effect, but its preparation process is complex and the production cost is high, which limits its large-scale use.

Therefore, there is an urgent need to provide a method for preparing an adsorbent with low cost and good adsorption performance.

Summary of the invention

In order to solve the above problems, the object of the present invention is to provide a grapefruit peel adsorbent and a preparation method and application thereof.

The present invention provides a method for preparing a grapefruit peel adsorbent, comprising the following steps:

Wash the grapefruit peel and remove surface stains;

Boil the washed grapefruit peel in 95-100℃ water;

Rinse the boiled grapefruit peels until they are neutral;

The washed grapefruit peel is soaked in a 0.1-0.5 mol/L calcium chloride solution, and then placed in an ultrasonic instrument for ultrasonication, wherein the temperature of the ultrasonication is 65-75° C. and the power is 60-70 Hz;

Rinse the grapefruit peels again after ultrasound until they are neutral;

Then dry the neutral grapefruit peel;

Finally, the dried grapefruit peel is crushed by a crusher and filtered through an 8-80 mesh sieve to obtain a grapefruit peel adsorbent.

Furthermore, the concentration of the calcium chloride solution is 0.4 mol/L.

Furthermore, the mesh size is 40 mesh.

Furthermore, the temperature of the ultrasound is 68° C. and the power is 70 Hz.

Furthermore, the ultrasonic treatment time is 20-40 minutes.

Furthermore, the ultrasonic time is 20 minutes.

Furthermore, the boiling time is 20-30 minutes.

Furthermore, the boiling time is 20 minutes.

The invention also provides a grapefruit peel adsorbent, which is prepared by the preparation method.

The present invention also provides an application of the grapefruit peel adsorbent in preparing a cigarette filter, wherein the grapefruit peel adsorbent is used to reduce the amount of nicotine inhaled in cigarettes.

Furthermore, the amount of the grapefruit peel adsorbent is 0.05-0.2g.

Furthermore, the amount of the grapefruit peel adsorbent is 0.1 g.

Furthermore, the cigarette filter also contains other filter additives.

Furthermore, the other cigarette filter additives are selected from Chinese herbal medicine, mineral materials, biological reagents, filter materials with adsorption properties or nanomaterials.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The present invention finds that grapefruit peel adsorbent treated with different calcium chloride concentrations has different effects on the nicotine adsorption effect. With the increase of the calcium chloride concentration gradient, the adsorption of nicotine first increases and then decreases. When the calcium chloride concentration is 0.5 mol/L, the adsorption rate is 15.1%. When the calcium chloride concentration reaches 0.4 mol/L, the adsorption rate can reach 34.8%. Different adsorbent particle sizes have different effects on the nicotine adsorption effect. When the particle size of the grapefruit peel adsorbent becomes larger and larger, the adsorption of nicotine generally shows a trend of first slowly increasing and then slowly decreasing. When the particle size is 40 mesh, the adsorption rate is the largest, which is 40.3%. Different grapefruit peel adsorbent addition amounts have different effects on the nicotine adsorption effect. With the increase of the amount of grapefruit peel adsorbent added, the nicotine adsorption generally shows a trend of first increasing and then decreasing. When the addition amount is 0.1g and 0.15g, the adsorption effect is better, and when the addition amount is 0.1g, the adsorption effect is the best, and the adsorption rate is 39.7%; different adsorbents have different effects on the nicotine adsorption effect. With the increase of adsorption time, the adsorption rate of the grapefruit peel adsorbent of the present invention is the highest, and the adsorption rate of nicotine by acetate fiber is the lowest. Compared with the same period, the adsorption effect of activated carbon is not as good as that of diatomaceous earth, and the adsorption rate of the original grapefruit peel adsorbent is greater than that of acetate fiber, but less than that of activated carbon and diatomaceous earth.

(2) The material preparation of the present invention uses agricultural waste grapefruit peel as raw material, which can turn waste into treasure; secondly, the material preparation is convenient, the process is simple, the cost is low, it is green and environmentally friendly, and it will not cause secondary pollution to the environment.

(3) The grapefruit peel adsorbent prepared by the present invention has good adsorption performance for nicotine, can adsorb nicotine in smoke, reduce its harm to the human body, reduce its pollution to the environment, and has broad application prospects.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is an adsorption device of the present invention;

In the figure, A is the opening of the rubber tube;

B is water-stop clamp;

C is the connection between the vacuum pump and the water stop clamp, through which the gas flow is controlled;

D is a suction filtration bottle.

FIG. 2 shows the effect of different calcium chloride concentrations on the adsorption of nicotine in smoke according to the present invention.

FIG. 3 shows the effect of different adsorbent particle sizes on nicotine adsorption rate of the present invention.

FIG. 4 shows the effect of different amounts of grapefruit peel adsorbent added on nicotine adsorption rate of the present invention.

FIG. 5 shows the effect of different adsorbents on the nicotine adsorption rate of the present invention.

FIG6 is a Fourier transform infrared spectrum analysis of the present invention;

In the figure, 1 is the grapefruit peel adsorbent after adsorption;

2 is a grapefruit peel adsorbent;

Line 3 is the original grapefruit peel adsorbent.

FIG7 is an X-ray analysis of the present invention;

In the figure, 1 is the grapefruit peel adsorbent after adsorption;

2 is a grapefruit peel adsorbent;

3 is the original grapefruit peel adsorbent.

DETAILED DESCRIPTION

In order to make the purpose and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Unless otherwise specified, the technical means used in the following examples are conventional means well known to those skilled in the art, and the materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial sources.

Experimental materials and instruments:

The experimental materials and instruments used in the present invention are as follows:

1. Experimental materials: pomelo peels, collected from the pomelo peel discarded basket in the Royal Fruit Shop at Thanksgiving Plaza.

2. Experimental reagents: Sodium hydroxide, Tianjin Ruijinte Chemical Company; Potassium permanganate, Luoyang Haohua Chemical Reagent Company; Calcium chloride, Tianjin Ruijinte Chemical Products Company; Activated carbon, Tianjin Damao Chemical Reagent Factory.

3. Instruments and equipment: Electronic balance WT3003, Hangzhou Wantehengqi Co., Ltd.; Water bath HH-4, Shanghai Experimental Instrument Factory; Pulverizer WB1110, Shanghai Precision Scientific Instrument Co., Ltd. Leici Instrument Factory; Drying oven WPL-65BE, Tianjin Tester Co., Ltd.; Element analyzer VarioELcude, German elementar company; Fourier transform infrared spectrometer TENSOR 27, German Bruker company.

Example 1: Preparation of a grapefruit peel adsorbent.

1. Raw material processing: clean the grapefruit peel with running tap water to remove surface stains;

2. Boil: Place the washed grapefruit peel in 100℃ water for 20 minutes;

3. Rinse: Rinse the boiled grapefruit peel under running tap water until it becomes neutral;

4. Ultrasonic hydrolysis: Soak the grapefruit peel that has been washed to neutrality in 0.1 mol/L calcium chloride solution, and put it in an ultrasonic instrument at 68°C and 70 Hz for 20 minutes;

5. Rinse: Use running tap water to wash the grapefruit peel after ultrasound until it becomes neutral;

6. Drying: drain the grapefruit peel that appears neutral, put it into a constant temperature drying oven for drying, and then crush it with a grinder; finally, filter it with a 60-mesh sieve to obtain the modified grapefruit peel residue, i.e., grapefruit peel adsorbent, and store it.

Example 2: Preparation of a grapefruit peel adsorbent.

1. Raw material processing: clean the grapefruit peel with running tap water to remove surface stains;

2. Boil: Place the washed grapefruit peel in 100℃ water for 20 minutes;

3. Rinse: Rinse the boiled grapefruit peel under running tap water until it becomes neutral;

4. Ultrasonic hydrolysis: Soak the grapefruit peel that has been washed to neutrality in 0.2 mol/L calcium chloride solution, and put it in an ultrasonic instrument at 68°C and 70 Hz for 20 minutes;

5. Rinse: Use running tap water to wash the grapefruit peel after ultrasound until it becomes neutral;

6. Drying: drain the grapefruit peel that appears neutral, put it into a constant temperature drying oven for drying, and then crush it with a grinder; finally, filter it with a 60-mesh sieve to obtain the modified grapefruit peel residue, i.e., grapefruit peel adsorbent, and store it.

Example 3: Preparation of a grapefruit peel adsorbent.

1. Raw material processing: clean the grapefruit peel with running tap water to remove surface stains;

2. Boil: Place the washed grapefruit peel in 100℃ water for 20 minutes;

3. Rinse: Rinse the boiled grapefruit peel under running tap water until it becomes neutral;

4. Ultrasonic hydrolysis: Soak the grapefruit peel that has been washed to neutrality in 0.3 mol/L calcium chloride solution, and put it in an ultrasonic instrument at 68°C and 70 Hz for 20 minutes;

5. Rinse: Use running tap water to wash the grapefruit peel after ultrasound until it becomes neutral;

6. Drying: drain the grapefruit peel that appears neutral, put it into a constant temperature drying oven for drying, and then crush it with a grinder; finally, filter it with a 60-mesh sieve to obtain the modified grapefruit peel residue, i.e., grapefruit peel adsorbent, and store it.

Example 4: Preparation of a grapefruit peel adsorbent.

1. Raw material processing: clean the grapefruit peel with running tap water to remove surface stains;

2. Boil: Place the washed grapefruit peel in 100℃ water for 20 minutes;

3. Rinse: Rinse the boiled grapefruit peel under running tap water until it becomes neutral;

4. Ultrasonic hydrolysis: Soak the grapefruit peel that has been washed to neutrality in 0.4 mol/L calcium chloride solution, and put it in an ultrasonic instrument at 68°C and 70 Hz for 20 minutes;

5. Rinse: Use running tap water to wash the grapefruit peel after ultrasound until it becomes neutral;

6. Drying: drain the grapefruit peel that appears neutral, put it into a constant temperature drying oven for drying, and then crush it with a grinder; finally, filter it with a 60-mesh sieve to obtain the modified grapefruit peel residue, i.e., grapefruit peel adsorbent, and store it.

Example 5: Preparation of a grapefruit peel adsorbent.

1. Raw material processing: clean the grapefruit peel with running tap water to remove surface stains;

2. Boil: Place the washed grapefruit peel in 100℃ water for 20 minutes;

3. Rinse: Rinse the boiled grapefruit peel under running tap water until it becomes neutral;

4. Ultrasonic hydrolysis: Soak the grapefruit peel that has been washed to neutrality in 0.5 mol/L calcium chloride solution, and put it in an ultrasonic instrument at 68°C and 70 Hz for 20 minutes;

5. Rinse: Use running tap water to wash the grapefruit peel after ultrasound until it becomes neutral;

6. Drying: drain the neutral grapefruit peel, put it into a 55°C constant temperature drying oven and dry it to constant weight, then crush it with a grinder; finally filter it with a 60-mesh sieve to obtain the modified grapefruit peel residue, i.e., grapefruit peel adsorbent, and store it.

Example 6: Preparation of a grapefruit peel adsorbent.

1. Raw material processing: clean the grapefruit peel with running tap water to remove surface stains;

2. Boil: Place the washed grapefruit peel in 100℃ water for 20 minutes;

3. Rinse: Rinse the boiled grapefruit peel under running tap water until it becomes neutral;

4. Ultrasonic hydrolysis: Soak the grapefruit peel that has been washed to neutrality in 0.4 mol/L calcium chloride solution, and put it in an ultrasonic instrument at 68°C and 70 Hz for 20 minutes;

5. Rinse: Use running tap water to wash the grapefruit peel after ultrasound until it becomes neutral;

6. Drying: drain the grapefruit peel that appears neutral, put it into a constant temperature drying oven for drying, and then crush it with a grinder; finally, filter it with a 40-mesh sieve to obtain the modified grapefruit peel residue, i.e., grapefruit peel adsorbent, and store it.

Example 7: Preparation of a grapefruit peel adsorbent.

1. Raw material processing: clean the grapefruit peel with running tap water to remove surface stains;

2. Boil: Place the washed grapefruit peel in 100℃ water for 20 minutes;

3. Rinse: Rinse the boiled grapefruit peel under running tap water until it becomes neutral;

4. Ultrasonic hydrolysis: Soak the grapefruit peel that has been washed to neutrality in 0.4 mol/L calcium chloride solution, and put it in an ultrasonic instrument at 68°C and 70 Hz for 20 minutes;

5. Rinse: Use running tap water to wash the grapefruit peel after ultrasound until it becomes neutral;

6. Drying: drain the grapefruit peel that appears neutral, put it into a constant temperature drying oven for drying, and then crush it with a grinder; finally, filter it with an 8-mesh sieve to obtain the modified grapefruit peel residue, i.e., grapefruit peel adsorbent, and store it.

Example 8: Preparation of a grapefruit peel adsorbent.

1. Raw material processing: clean the grapefruit peel with running tap water to remove surface stains;

2. Boil: Place the washed grapefruit peel in 100℃ water for 20 minutes;

3. Rinse: Rinse the boiled grapefruit peel under running tap water until it becomes neutral;

4. Ultrasonic hydrolysis: Soak the grapefruit peel that has been washed to neutrality in 0.4 mol/L calcium chloride solution, and put it in an ultrasonic instrument at 68°C and 70 Hz for 20 minutes;

5. Rinse: Use running tap water to wash the grapefruit peel after ultrasound until it becomes neutral;

6. Drying: drain the grapefruit peel that appears neutral, put it into a constant temperature drying oven for drying, and then crush it with a grinder; finally, filter it with an 18-mesh sieve to obtain the modified grapefruit peel residue, i.e., grapefruit peel adsorbent, and store it.

Example 9: Preparation of a grapefruit peel adsorbent.

1. Raw material processing: clean the grapefruit peel with running tap water to remove surface stains;

2. Boil: Place the washed grapefruit peel in 100℃ water for 20 minutes;

3. Rinse: Rinse the boiled grapefruit peel under running tap water until it becomes neutral;

4. Ultrasonic hydrolysis: Soak the grapefruit peel that has been washed to neutrality in 0.4 mol/L calcium chloride solution, and put it in an ultrasonic instrument at 68°C and 70 Hz for 20 minutes;

5. Rinse: Use running tap water to wash the grapefruit peel after ultrasound until it becomes neutral;

6. Drying: drain the grapefruit peel that appears neutral, put it into a constant temperature drying oven for drying, and then crush it with a grinder; finally, filter it with an 80-mesh sieve to obtain the modified grapefruit peel residue, i.e., grapefruit peel adsorbent, and store it.

Comparative Example 1:

The grapefruit peel is cleaned with running tap water to remove surface stains, placed in a constant temperature drying oven for drying and then crushed with a grinder; finally, filtered with a 60-mesh sieve to obtain unmodified grapefruit peel residue, i.e., original grapefruit peel adsorbent, which is then stored.

Comparative Example 2: Activated carbon was used as the adsorbent; the activated carbon was purchased from Tianjin Damao Chemical Reagent Factory.

Comparative Example 3: Acetate fiber is used as the adsorbent; the acetate fiber is the acetate fiber pulled out from cigarettes (Hongqi Canal).

Comparative Example 4: Diatomaceous earth was used as the adsorbent; the diatomaceous earth was purchased from Thermo Fisher Scientific (China) Co., Ltd.

Application example 1: Determination of adsorption rate.

1. Effect of grapefruit peel adsorbent treated with different calcium chloride concentrations on nicotine adsorption

Weigh 0.2 g of the grapefruit peel adsorbents in Examples 1 to 5, respectively, and put them into the filter paper sleeves of cigarettes (Hongqiqu) from which the acetate fiber has been removed, and then insert the paper sleeves;

Put the cigarette after the acetate fiber treatment on the adsorption device (Figure 1) and clamp it with a water stop clamp. Turn on the vacuum pump until the vacuum pump pressure reaches 0.095MPa (bubbles appear at this time), open the water stop clamp, light the cigarette, and turn off the vacuum pump and water stop clamp when the cigarette is burned out. Let the smoke completely dissolve in 150mL of distilled water, pour it into a 250mL volumetric flask, and let it stand for 20 minutes.

After 20 minutes, add 5g of sodium hydroxide and 0.02765g of potassium permanganate, and finally adjust the volume to the 250mL mark;

Place in a water bath at 100°C for 8 minutes, cool to room temperature, filter the upper layer of liquid, and take the filtrate;

The nicotine content in cigarette smoke was determined by spectrophotometry.

The calculation formula for the adsorption rate of nicotine by the adsorbent is: adsorption rate = (M1-M1')/M1; wherein: M1 is the total amount of nicotine in the filtration device solution (1.5+blank), and M1' is the nicotine content in the filtration device solution during each experiment.

As shown in Figure 2, with the increase of calcium chloride concentration gradient, the adsorption of nicotine first increases and then decreases. When the calcium chloride concentration reaches 0.4 mol/L, the adsorption rate can reach 34.8%; when the calcium chloride concentration is 0.5 mol/L, the adsorption rate is 15.1%.

2. Effect of different adsorbent particle sizes on nicotine adsorption

Weigh 0.1 g of grapefruit peel adsorbents from Examples 4 and 6-9, respectively, and put them into the filter paper sleeves of cigarettes (Hongqiqu) from which acetate fiber has been removed, and then insert the paper sleeves;

Put the cigarette after the acetate fiber treatment on the adsorption device (Figure 1) and clamp it with a water stop clamp. Turn on the vacuum pump until the vacuum pump pressure reaches 0.095MPa (bubbles appear at this time), open the water stop clamp, light the cigarette, and turn off the vacuum pump and water stop clamp when the cigarette is burned out. Let the smoke completely dissolve in 150mL of distilled water, pour it into a 250mL volumetric flask, and let it stand for 20 minutes.

After 20 minutes, add 5g of sodium hydroxide and 0.02765g of potassium permanganate, and finally adjust the volume to the 250mL mark;

Place in a water bath at 100°C for 8 minutes, cool to room temperature, filter the upper layer of liquid, and take the filtrate;

The nicotine content in cigarette smoke was determined by spectrophotometry.

As shown in Figure 3, when the particle size of the grapefruit peel adsorbent becomes larger and larger, the adsorption of nicotine generally shows a trend of first slowly increasing and then slowly decreasing, and the adsorption rate is the largest when the particle size is 40 mesh, which is 40.3%.

3. Effect of different amounts of grapefruit peel adsorbent on nicotine adsorption

Weigh 0.05g, 0.1g, 0.15g, 0.2g, and 0.25g of the grapefruit peel adsorbent in Example 6, respectively, and put them into the filter paper sleeve of a cigarette (Hongqiqu) from which the acetate fiber has been removed, and then insert the paper sleeve;

Put the cigarette after the acetate fiber treatment on the adsorption device (Figure 1) and clamp it with a water stop clamp. Turn on the vacuum pump until the vacuum pump pressure reaches 0.095MPa (bubbles appear at this time), open the water stop clamp, light the cigarette, and turn off the vacuum pump and water stop clamp when the cigarette is burned out. Let the smoke completely dissolve in 150mL of distilled water, pour it into a 250mL volumetric flask, and let it stand for 20 minutes.

After 20 minutes, add 5g of sodium hydroxide and 0.02765g of potassium permanganate, and finally adjust the volume to the 250mL mark;

Place in a water bath at 100°C for 8 minutes, cool to room temperature, filter the upper layer of liquid, and take the filtrate;

The nicotine content in cigarette smoke was determined by spectrophotometry.

As shown in Figure 4, with the increase in the amount of grapefruit peel adsorbent added, the overall nicotine adsorption shows a trend of first increasing and then decreasing. When the added amount is 0.1g and 0.15g, the adsorption effect is better; when the added amount is 0.1g, the adsorption effect is the best, and the adsorption rate is 39.7%.

4. Effect of different adsorbents on nicotine adsorption

0.1 g of the grapefruit peel adsorbent in Example 4, the original grapefruit peel adsorbent in Comparative Example 1, and the adsorbents in Comparative Examples 2-4 were weighed respectively, and were placed in the filter paper sleeves of cigarettes from which acetate fiber had been removed (the cigarettes used were shown in Table 1), and then the paper sleeves were inserted; the cigarettes from which acetate fiber had been removed were clamped on the adsorption device and clamped with a water stop clamp, and the vacuum pump was turned on until the vacuum pump pressure reached 0.095 MPa (bubbles appeared at this time), and the water stop clamp was opened, and the cigarette was lit. When one cigarette was burned out, the vacuum pump and the water stop clamp were turned off, and the smoke was completely dissolved in 150 mL of distilled water, poured into a 250 mL volumetric flask, and allowed to stand for 20 minutes;

After 20 minutes, add 5g of sodium hydroxide and 0.02765g of potassium permanganate, and finally adjust the volume to the 250mL mark;

Place in a water bath at 100°C for 8 minutes, cool to room temperature, filter the upper layer of liquid, and take the filtrate;

The nicotine content in cigarette smoke was determined by spectrophotometry.

Table 1 Nicotine content in cigarettes

Cigarette Brand Origin Nicotine content (mg) Red Flag Canal Henan Tobacco Industry 0.7

As shown in Figure 5, with the increase of adsorption time, the adsorption rate of the grapefruit peel adsorbent of the present invention is the highest, and the adsorption rate of nicotine by acetate fiber is the lowest. Compared with the same period, the adsorption effect of activated carbon is not as good as that of diatomaceous earth, and the adsorption rate of the original grapefruit peel adsorbent is greater than that of acetate fiber, but less than that of activated carbon and diatomaceous earth.

Application example 2: Fourier transform infrared spectroscopy analysis.

200 mg of potassium bromide was added to a mortar, and 2 mg of the treated grapefruit peel adsorbent in Example 6 and the original grapefruit peel adsorbent in Comparative Example 1 were taken respectively, and the mixture was fully ground with potassium bromide, and poured into a tablet, which was pressed into a transparent tablet on a tablet press, and scanned under a Fourier infrared spectrometer to measure the spectrum;

Then, the grapefruit peel adsorbent that has absorbed nicotine in Application Example 1 is taken again, and it is fully ground with potassium bromide, poured into tablets after mixing, pressed into a transparent state on a tablet press, and scanned under a Fourier infrared spectrometer to measure the spectrum;

The changes in the properties of the grapefruit peel adsorbent before and after adsorption and before and after modification were judged based on the spectra of different adsorbents.

From the analysis of Figure 6 1 and 2, it can be seen that the adsorption fluctuation changes at 1800cm ^-1 ~ 3412cm ^-1 , 1500cm ^-1 ~ 1750cm ^-1 , 1110cm ^-1 ~ 1400cm ^-1 and 650cm ^-1 ~ 750cm ^-1 , that is, the groups -OH, C = O, C = C, CH have peak changes, indicating that these groups play a role in the adsorption process, which shows that chemical adsorption plays an important role in this adsorption process. From the comparison of Figure 6 2 and 3, it can be seen that the concentration of the groups in the modified grapefruit peel adsorbent is higher than that of the original grapefruit peel adsorbent.

Application example 3: elemental analysis.

3 mg of the original grapefruit peel adsorbent in Comparative Example 1, the grapefruit peel adsorbent in Example 6, and the grapefruit peel adsorbent adsorbed with nicotine in Application Example 1 (grapefruit peel adsorbent after adsorption) were weighed, placed on tin foil, and wrapped into small squares as the samples to be tested; the samples to be tested were placed in the element instrument for detection, and the results are shown in Table 2.

Table 2 Element content comparison table

N% C% H% S% Original grapefruit peel adsorbent 4.853 34.31 5.456 0.1402 Grapefruit peel adsorbent 1.869 40.85 6.202 0.0666 Grapefruit peel adsorbent after adsorption 2.032 39.1 6.029 0.0439

It can be seen from Table 2 that compared with the original grapefruit peel adsorbent, the contents of C, H, N, and S elements in the grapefruit peel adsorbent and the grapefruit peel adsorbent after adsorption have changed, indicating that the modified grapefruit peel adsorbent may change the number of polar groups such as C＝N and COOH in the grapefruit peel, thereby playing an important role in the adsorption; the H element content of the grapefruit peel adsorbent increases, indicating that the method of the present invention increases the number of groups such as carboxyl and hydroxyl in the grapefruit peel, and these groups play a great role in the adsorption of nicotine.

Application example 4: X-ray analysis.

According to the method in Application Example 2, the grapefruit peel adsorbent in Example 6, the original grapefruit peel adsorbent in Comparative Example 1, and the grapefruit peel adsorbent after nicotine adsorption in Application Example 1 (grapefruit peel adsorbent after adsorption) were respectively prepared into slides and placed in an X-ray diffractometer (XRD) for detection. The crystallinity was determined based on the peaks, thereby analyzing the structural properties.

From the analysis of Figure 7, it can be seen that there is a strong characteristic diffraction peak at 2θ=22.5°, representing the crystalline area of cellulose; the diffraction peak of the original grapefruit peel adsorbent is the smallest, followed by the treated one, and the diffraction peak of the grapefruit peel adsorbent after adsorption is the largest. The crystallinity of the grapefruit peel adsorbent is enhanced during the entire adsorption process, and the physical structure is more stable, indicating that physical adsorption also exists in the grapefruit peel adsorbent during the entire adsorption process.

Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims (10)

1. A method for preparing a grapefruit peel adsorbent, characterized in that it comprises the following steps: Boil the grapefruit peels; Rinse the boiled grapefruit peels until they are neutral; The washed grapefruit peel is immersed in a 0.1-0.5 mol/L calcium chloride solution, and then ultrasonicated at a temperature of 65-75°C and a power of 60-70 Hz; The grapefruit peel after ultrasonic treatment is rinsed again until it is neutral and then dried; Finally, the dried grapefruit peel is crushed and filtered through an 8-80 mesh sieve to obtain a grapefruit peel adsorbent. 2. The method for preparing a grapefruit peel adsorbent according to claim 1, wherein the concentration of the calcium chloride solution is 0.4 mol/L. 3. The method for preparing a grapefruit peel adsorbent according to claim 1, wherein the mesh sieve is 40 mesh. 4. The method for preparing a grapefruit peel adsorbent according to claim 1, characterized in that the temperature is 68°C and the power is 70 Hz. 5. The method for preparing a grapefruit peel adsorbent according to claim 1, wherein the ultrasonic time is 20-40 min. 6. The method for preparing a grapefruit peel adsorbent according to claim 1, characterized in that the boiling temperature is 95-100°C and the boiling time is 20-30 minutes. 7. A grapefruit peel adsorbent, characterized in that it is prepared by the preparation method according to any one of claims 1 to 6. 8. Use of the grapefruit peel adsorbent according to claim 7 in the preparation of cigarette filters, characterized in that the grapefruit peel adsorbent is used to reduce the amount of nicotine inhaled in cigarettes. 9. Use of the grapefruit peel adsorbent in the preparation of cigarette filters according to claim 8, characterized in that the amount of the grapefruit peel adsorbent is 0.05-0.2g. 10. Use of the grapefruit peel adsorbent in preparing a cigarette filter according to claim 9, characterized in that the amount of the grapefruit peel adsorbent is 0.1 g.