Method and kit for detecting sucralose and application thereof

Abstract

The invention discloses a method and a kit for detecting sucralose and application of the method and the kit. The detection method comprises the following steps: adding a to-be-detected sample into a reaction solution, adding an acetate buffer solution, incubating to obtain a to-be-detected solution, measuring the characteristic absorbance of the to-be-detected solution to obtain a light absorption detection value, and determining the concentration of sucralose in the to-be-detected sample according to the light absorption detection value, the reaction solution comprises 3, 3 ', 5, 5'-tetramethyl benzidine, H2O2 and neutral gamma-CD-MOFs, and the neutral gamma-CD-MOFs is a cyclodextrin metal organic framework constructed by gamma-cyclodextrin and potassium ions. The invention discloses that neutral gamma-CD-MOFs have peroxidase-like catalytic activity for the first time, based on interaction of sucralose and the neutral gamma-CD-MOFs, affinity with a substrate is enhanced, more OH is generated, peroxidase-like activity of the neutral gamma-CD-MOFs is increased, sucralose detection is achieved, and the advantages of being rapid, easy to operate, specific and high in detection accuracy are achieved.

Description

Technical Field

[0001] This application relates to the field of chemical component detection technology, and in particular to a method, kit, and application for detecting sucralose. Background Technology

[0002] Sweeteners are frequently added to atomized matrices and oral products, primarily to improve sensory palatability. Sucralose, a synthetic sweetener, chemically named 1,6-dichloro-1,6-dideoxy-β-D-fructofuranosyl-4-chloro-4-deoxy-α-D-galactopyranoside (IUPAC designation), is the most widely used sugar substitute. Similar in structure to sucrose, sucralose is chemically synthesized by replacing three hydroxyl groups with chlorine atoms, with one chlorine atom adopting an inverted stereochemistry relative to the corresponding hydroxyl group in the sucrose parent molecule. The cumulative effect of these structural changes makes sucralose 400 to 700 times more sweet than sucrose by weight.

[0003] Although sucralose was initially considered safe, new evidence suggests that the compound can degrade even under mild thermal conditions, leading to the production of toxic polychlorinated aromatic hydrocarbons; therefore, it is essential to achieve reliable, rapid and low-cost analysis of sucralose. Summary of the Invention

[0004] The purpose of this application is to provide a new method for detecting sucralose, a kit for this detection method, and its application.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] This application discloses a method for detecting sucralose, wherein the sample to be tested is added to a reaction solution, acetate buffer is added, and incubation is performed to obtain a test solution. The characteristic absorbance of the test solution is measured to obtain an absorbance detection value, and the concentration of sucralose in the sample is determined based on the absorbance detection value. The reaction solution includes 3,3',5,5'-tetramethylbenzidine, H2O2, and neutral γ-CD-MOFs, wherein the neutral γ-CD-MOFs are cyclodextrin metal-organic frameworks constructed from γ-cyclodextrin and potassium ions.

[0007] In one implementation of this application, the absorbance detection value is the characteristic absorbance of the test liquid at 654 nm.

[0008] In one implementation of this application, the incubation temperature is 37°C.

[0009] In one implementation of this application, the incubation time is 20 min to 30 min.

[0010] In one implementation of this application, the concentration of sucralose in the sample to be tested is determined based on the absorbance detection value, specifically including: obtaining an absorbance analysis regression equation, wherein the absorbance analysis regression equation is obtained based on the sucralose concentration of several standard samples and the corresponding absorbance detection values ​​of several standard samples; and determining the concentration of sucralose in the sample to be tested based on the absorbance detection value of the test liquid and the absorbance analysis regression equation.

[0011] In one implementation of this application, the light absorption analysis regression equation is:

[0012] y = 0.001[Sucralose] + 0.427

[0013] Wherein, sucralose is the concentration of sucralose, and y is the absorbance value detected by light.

[0014] In one implementation of this application, the absorbance analysis regression equation is applicable to the detection of test samples with sucralose concentrations ranging from 3.13 μg / mL to 250 μg / mL.

[0015] In one implementation of this application, the concentration of neutral γ-CD-MOFs in the reaction solution is 1 mg / mL, the concentration of 3,3',5,5'-tetramethylbenzidine is 5 mmol / L, and the concentration of H2O2 is 50 mmol / L.

[0016] In one implementation of this application, the pH value of the acetate buffer solution is 4;

[0017] In one implementation of this application, the concentration of the acetate buffer is 0.1~0.2 mol / L.

[0018] In one implementation of this application, the method further includes preparing neutral γ-CD-MOFs before adding the sample to be tested to the reaction solution: γ-cyclodextrin and KOH are added to deionized water and completely dissolved. Methanol is then added to obtain a mixture. The mixture is then placed in a sealed container containing methanol, and the methanol in the container is evaporated and diffused into the mixture. After centrifugation, the supernatant is collected, hexadecyltrimethylammonium bromide is added, and the solution is mixed. The mixture is incubated overnight at room temperature, centrifuged, and the precipitate is collected, washed, and dried to obtain basic γ-CD-MOFs. The basic γ-CD-MOFs are dissolved in anhydrous ethanol and glacial acetic acid, stirred and mixed evenly, centrifuged, and the precipitate is collected, washed, and dried to obtain neutral γ-CD-MOFs.

[0019] This application also discloses a kit for detecting sucralose, comprising neutral γ-CD-MOFs.

[0020] In one implementation of this application, the kit further includes at least one of 3,3',5,5'-tetramethylbenzidine, H2O2, acetate buffer solution, and sucralose standard of known concentration.

[0021] This application also discloses the application of the reagent kit of this application in the detection of sucralose in atomized matrix or oral products.

[0022] Due to the adoption of the above technical solutions, the beneficial effects of this application are as follows:

[0023] This application discloses a method for sucralose detection that utilizes the metal-organic framework of green, biocompatible γ-cyclodextrin for sucralose detection. It is the first to reveal that neutral γ-CD-MOFs possess excellent peroxidase-like catalytic activity. Based on the interaction between sucralose and neutral γ-CD-MOFs, the affinity for the substrate is enhanced, generating more ˙OH, thereby increasing the peroxidase-like activity of neutral γ-CD-MOFs and achieving highly sensitive and specific detection of sucralose. This method is rapid, simple to operate, specific, and highly accurate, with a high recovery rate, providing a new visualization strategy for sucralose detection. Attached Figure Description

[0024] Figure 1 Here are SEM images of the neutral γ-CD-MOFs synthesized in the embodiments of this application;

[0025] Figure 2 is an FTIR spectrum of the neutral γ-CD-MOFs synthesized in the embodiments of this application;

[0026] Figure 3 is the XRD pattern of the neutral γ-CD-MOFs synthesized in the embodiments of this application;

[0027] Figure 4 The UV-Vis absorption spectra of neutral γ-CD-MOFs+TMB+H2O2 and neutral γ-CD-MOFs+TMB+H2O2+Sucralose synthesized in the embodiments of this application are shown below.

[0028] Figure 5 In Example 1 of this application Figure 5 The Michaelis-Menten kinetic curves for the oxidation of TMB (Figure a) and H2O2 (Figure b) by neutral γ-CD-MOFs in Example 1 are shown.

[0029] Figure 6 The Michaelis kinetic curves for the oxidation of TMB (Figure a) and H2O2 (Figure b) by neutral γ-CD-MOFs+ Sucralose in Example 1 of this application are shown.

[0030] Figure 7ESR diagrams of DMPO / ˙OH for neutral γ-CD-MOFs and neutral γ-CD-MOFs+ Sucralose in Example 1 of this application;

[0031] Figure 8 The absorption spectrum (Figure a) and linear fitting curve (Figure b) of sucralose in the embodiments of this application are shown.

[0032] Figure 9 The results show the potential impact of interfering substances on the sucralose colorimetric detection system in the embodiments of this application. Detailed Implementation

[0033] Unlike traditional metal-organic frameworks (MOFs) constructed from synthetic ligands or transition metals, cyclodextrin (CD)-based metal-organic frameworks (CD-MOFs) are a novel type of edible and biocompatible MOFs. They are synthesized via a gas-phase diffusion method based on alkali metal ions and CD. Currently reported CD-MOFs are mainly used for drug delivery and encapsulation of volatile substances, while research on the activity of CD-MOF-based nanozymes is rarely reported.

[0034] This application is the first to discover that neutral γ-CD-MOFs have excellent peroxidase-like catalytic activity. Based on the interaction between sucralose and neutral γ-CD-MOFs, the affinity for the substrate is enhanced, more ˙OH is generated, thereby increasing the POD-like activity of neutral γ-CD-MOFs.

[0035] Based on the above research and understanding, this application provides a novel method for detecting sucralose. The method involves adding the sample to be tested to a reaction solution, adding acetate buffer, and incubating to obtain a test solution. The characteristic absorbance of the test solution is measured to obtain an absorbance detection value, and the concentration of sucralose in the sample is determined based on the absorbance detection value. The reaction solution includes 3,3',5,5'-tetramethylbenzidine (TMB), H2O2, and neutral γ-CD-MOFs, where the neutral γ-CD-MOFs are cyclodextrin metal-organic frameworks constructed from γ-cyclodextrin and potassium ions.

[0036] It should be noted that this application creatively utilizes a cyclodextrin metal-organic framework constructed from γ-cyclodextrin and potassium ions as a colorimetric sensor for the colorimetric detection of sucralose. Neutral γ-CD-MOFs exhibit excellent peroxidase-like (POD-like) activity. Based on the enhancing effect of sucralose on the POD-like activity of neutral γ-CD-MOFs, a simple and sensitive biosensor is constructed, enabling the colorimetric detection of sucralose. The detection method of this application demonstrates excellent performance in actual nicotine bag sample analysis, maintaining a low detection limit of 1.74 μg / mL while showing a satisfactory recovery range, from 97.0% to 102.3%. This nanozyme-based colorimetric method provides a new visualization strategy for the detection of sucralose in electronic nebulizers, exhibiting good specificity and sensitivity.

[0037] In some embodiments, the absorbance detection value is the characteristic absorbance of the test liquid at 654 nm.

[0038] In some embodiments, the incubation temperature is 37°C.

[0039] In some embodiments, the incubation time is 20 min to 30 min.

[0040] Understandably, the incubation conditions are primarily intended to ensure that sucralose in the sample comes into full contact with and reacts with neutral γ-CD-MOFs.

[0041] In some embodiments, determining the concentration of sucralose in the sample to be tested based on the absorbance detection value specifically includes: obtaining an absorbance analysis regression equation, wherein the absorbance analysis regression equation is obtained based on the sucralose concentration of several standard samples and the corresponding absorbance detection values ​​of several standard samples; and determining the concentration of sucralose in the sample to be tested based on the absorbance detection value of the test solution and the absorbance analysis regression equation.

[0042] It should be noted that the absorbance of sucralose at a known concentration is measured, and a linear relationship is fitted between the measured absorbance and the known concentration to obtain a regression equation. In some embodiments, the absorbance analysis regression equation is: y = 0.001[Sucralose] + 0.427, R 2 The linear range was 3.13–250 μg / mL, with a value of 0.991. Here, "Sucralose" refers to the concentration of sucralose, and y is the absorbance detection value. It should be noted that in this application, when "Sucralose" is used in the absorbance analysis regression equation and its interpretation, it specifically refers to the concentration of sucralose; elsewhere, it is used to refer to sucralose.

[0043] In some embodiments, the concentration of neutral γ-CD-MOFs in the reaction solution is 1 mg / mL, the concentration of 3,3',5,5'-tetramethylbenzidine is 5 mmol / L, and the concentration of H2O2 is 50 mmol / L.

[0044] In some embodiments, the pH of the acetate buffer is 4.

[0045] In some embodiments, the concentration of the acetate buffer is 0.1~0.2 mol / L.

[0046] In some embodiments, the preparation method of this application further includes the preparation of neutral γ-CD-MOFs before adding the sample to be tested to the reaction solution:

[0047] γ-Cyclodextrin and KOH were added to deionized water and dissolved completely. Methanol was then added to obtain a mixture. The mixture was placed in a sealed container containing methanol, and the methanol in the container was evaporated and diffused into the mixture. The mixture was centrifuged, and the supernatant was collected. Cetyltrimethylammonium bromide was added, and the solution was mixed well. The mixture was incubated overnight at room temperature, centrifuged, and the precipitate was collected, washed, and dried to obtain basic γ-CD-MOFs. The basic γ-CD-MOFs were dissolved in anhydrous ethanol and glacial acetic acid, stirred and mixed evenly, centrifuged, and the precipitate was collected, washed, and dried to obtain neutral γ-CD-MOFs.

[0048] In some embodiments, the conditions for evaporating and diffusing methanol from the tank into the mixture include evaporating methanol at 50 °C for 6-7 h.

[0049] Based on the sucralose detection method of this application, this application uses key components to form a sucralose detection kit, which in particular includes neutral γ-CD-MOFs.

[0050] In some embodiments, for ease of use, the kit of this application further includes at least one of 3,3',5,5'-tetramethylbenzidine, H2O2, acetate buffer solution, and sucralose standard of known concentration.

[0051] In some embodiments, the kit of this application is used for the detection of sucralose in atomized matrices or oral products.

[0052] Oral products refer to products that release their active ingredients and / or flavorings through oral dissolution. They come in various forms, including but not limited to lozenges, lozenge sachets, lozenge films, and various novel forms of oral products. In some embodiments, the active ingredient may include at least one of nicotine and / or nicotine derivatives. In some embodiments, the active ingredient may include substances with specific medical or other active properties, such as vitamins, caffeine, theophylline, tea polyphenols, etc. Exemplary oral products may include nicotine dissolving films, caffeine sachets, nicotine tablets, nicotine hard candies, nicotine laminated tablets, etc.

[0053] The atomizing matrix refers to a matrix that can be atomized into an aerosol under heating or other conditions, and it generally includes active ingredients and / or flavoring agents. In some embodiments, the active ingredient may include at least one of nicotine and / or nicotine derivatives. In some embodiments, the active ingredient may include substances with specific medical or other active properties, such as vitamins, caffeine, theophylline, tea polyphenols, and other active substances.

[0054] The present application will be further described in detail below through specific embodiments. The following embodiments are only for further illustration of the present application and should not be construed as limiting the present application.

[0055] Example

[0056] 1. Preparation of basic γ-CD-MOFs

[0057] 162 mg γ-CD and 56 mg KOH were added to 5 mL of deionized water and stirred to dissolve. The solution was filtered through a 0.45 μm filter to remove particulate matter. 0.5 mL of methanol was added, and the mixture was placed in a sealed container containing methanol. The methanol was evaporated and diffused into the solution at 50 °C. After 6 h, the mixture was centrifuged at 4000 rpm for 10 min. The supernatant was transferred to another tube, and 56 mg CTAB was added. The solution was mixed and incubated overnight at room temperature. The precipitate was collected by centrifugation at 4000 rpm for 10 min, washed 3-4 times with isopropanol, and dried overnight at 37 °C to obtain basic γ-CD-MOFs.

[0058] 2. Preparation and characterization of neutral γ-CD-MOFs

[0059] Dissolve 600 mg of basic γ-CD-MOF in 25 mL of anhydrous ethanol and 2.2 mL of glacial acetic acid, stir for 40 min, centrifuge at 4000 rpm for 10 min, collect the precipitate, wash 3-4 times with anhydrous ethanol, and vacuum dry to obtain neutral γ-CD-MOF nanozyme.

[0060] The prepared neutral γ-CD-MOF nanozymes were analyzed by SEM, FTIR spectroscopy, and XRD. The results are as follows: Figures 1 to 3 As shown. Figure 1 This is an SEM image. Figure 2 For FTIR plots, Figure 3 This is an XRD pattern.

[0061] Figure 1 The results showed that the synthesized neutral γ-CD-MOFs crystals were successfully formed, with a clear cubic geometry and a side length of about 5 µm, consistent with the expected results.

[0062] Figure 2 FTIR spectral data show that its characteristic absorption is at 3434 cm⁻¹. -1 The nearby broad vibrational band corresponds to the OH stretching mode in primary and secondary hydroxyl groups, indicating hydrogen bonding interactions, 2926 cm⁻¹ -1 The significant absorption at 1645-1650 cm⁻¹ originates from the stretching vibration of the CH bond. -1 Spectral characteristics within the range of 1400-1200 cm⁻¹ indicate the presence of water molecules within the molecular framework. -1 The absorption bands within this range are attributed to CH deformation vibrations associated with primary and secondary hydroxyl functions present in neutral γ-CD-MOFs, and furthermore, at 1150 cm⁻¹. -1 and 1020 cm -1 The characteristic peaks at 950-700 cm⁻¹ are attributed to the C=O stretching vibrations of glycosidic bonds and primary alcohols, respectively. -1 The vibrational characteristics of the region originate from the stretching and contracting motion of the pyranose ring and the deformation mode of the CH bond.

[0063] It is noteworthy that neutral γ-CD-MOFs exhibit unique XRD characteristics; the disappearance of the 5.7° diffraction peak is accompanied by a significant decrease in reflection intensity at 16.8°, such as... Figure 3 As shown.

[0064] 3. Evaluation of peroxidase activity of neutral γ-CD-MOF nanozymes

[0065] Mix 100 μL of 5 mmol / L TMB, 100 μL of 50 mmol / L H2O2, and 100 μL of 1 mg / mL neutral γ-CD-MOFs solution. Add 0.1 mmol / L pH 4.0 acetate buffer solution to a final volume of 3 mL, shake well, and incubate at 37°C for 20 min. Then measure the absorbance at 654 nm; a distinct blue color was observed. Under the same conditions, add 100 μL of 50 μg / mL sucralose and measure its UV-Vis absorption spectrum. The results are as follows: Figure 4 As shown. Figure 4 In the above, γ-CD-MOFs (1) is the UV-Vis absorption spectrum of neutral γ-CD-MOFs, TMB and H2O2 without the addition of sucralose, i.e. γ-CD-MOFs+TMB+H2O2, γ-CD-MOFs+Sucralose (2) is the UV-Vis absorption spectrum of neutral γ-CD-MOFs, TMB and H2O2 with the addition of sucralose, i.e. γ-CD-MOF+TMB+H2O2+Sucralose.

[0066] Figure 4 The results showed that neutral γ-CD-MOFs had nanozyme POD-like activity, and the catalytic activity was significantly improved after the addition of sucralose, proving that sucralose has the characteristic of enhancing the peroxidase activity of neutral γ-CD-MOFs.

[0067] Simultaneously, Michaelis-Menten catalytic kinetic parameters were determined, and the results are as follows: Figure 5 , Figure 6 As shown in Table 1. Figure 5 In the figure, Figure a shows the Michaelis-Menten kinetics of TMB oxidation by neutral γ-CD-MOFs, and Figure b shows the Michaelis-Menten kinetics of H2O2 oxidation by neutral γ-CD-MOFs. Figure 6 In the figure, Figure a shows the Michaelis kinetics of the oxidation of TMB by neutral γ-CD-MOFs with sucralose, and Figure b shows the Michaelis kinetics of the oxidation of H2O2 by neutral γ-CD-MOFs with sucralose.

[0068] Table 1. Michaelis constants (K) with TMB and H2O2 as substrates m ) and maximum reaction rate (V max )

[0069] neutral γ-CD-MOFs Neutral γ-CD-MOFs + sucralose <![CDATA[TMB K m (mM)]]> 0.29 0.23 <![CDATA[H2O2K m (mM)]]> 1.16 1.08 <![CDATA[TMB V max (10 -8 M·s -1 )]]> 0.81 1.75 <![CDATA[H2O2V max (10 -8 M·s -1 )]]> 0.92 1.69

[0070] Figure 5 , Figure 6 The results in Table 1 show that, regardless of whether TMB or H2O2 is used as the substrate, sucralose significantly enhances the affinity of neutral γ-CD-MOF nanozymes for the substrate and the reaction rate.

[0071] To further confirm the catalytic mechanism of neutral γ-CD-MOF nanozymes, electron paramagnetic resonance (ESR) spectroscopy was performed using the probe 5,5-dimethyl-1-pyrrolline-N-oxide (DMPO), and the results are shown in Figure 7. Figure 7 In the figure, the curve for γ-CD-MOFs + Sucralose is the ESR spectrum of neutral γ-CD-MOFs with sucralose, and the curve for γ-CD-MOFs is the ESR spectrum of neutral γ-CD-MOFs.

[0072] Figure 7 The results showed that a significant ˙OH signal was observed in the neutral γ-CD-MOFs system, while the addition of sucralose significantly enhanced the ˙OH signal in the neutral γ-CD-MOFs system. The mechanisms by which sucralose enhances the POD-like activity of neutral γ-CD-MOFs include: 1) sucralose increases the affinity of nanozymes for substrates; 2) sucralose increases the generation of ˙OH during the catalytic process.

[0073] 4. Construction of Standard Curve

[0074] The colorimetric sensor method is based on the enhancement of POD-like activity of neutral γ-CD-MOFs by sucralose. Different concentrations of sucralose (10 μL), 5 mmol / L TMB (10 μL), 50 mmol / L H₂O₂ (10 μL), 1 mg / mL neutral γ-CD-MOFs solution (10 μL), and 0.1 mmol / L pH 4.0 acetate buffer (270 μL) were added to an ELISA plate. After mixing, the plate was incubated at 37 °C for 20 min, and absorbance was measured at 654 nm (see Table 2). A standard curve was then plotted with sucralose concentration on the x-axis and absorbance on the y-axis to obtain the regression equation, correlation coefficient, relative standard deviation, and linear range (see Table 3). Figure 8 . Figure 8 In the figure, the absorption spectrum of sucralose is shown in Figure a, and the linear fitting curve is shown in Figure b.

[0075] Table 2. Sucralose at different concentrations and their absorbance

[0076] Sucralose concentration (μg / mL) absorbance 3.13 0.4265 15.5625 0.4595 31.25 0.4762 62.5 0.504 125 0.5762 187.5 0.6453 250 0.76943

[0077] Table 3. Linear equation, correlation coefficient, relative standard deviation, and linear range

[0078] Sucralose Working curve y = 0.001[Sucralose] + 0.427 <![CDATA[Coefficient of correlation (R 2 )]]> 0.991 Linear range 3.13~250 μg / mL RSD% (n=3) 2.23 LOD 1.74 μg / mL

[0079] 5. Method specificity investigation

[0080] To investigate the selectivity of the method and the effect of potential interfering substances on the detection of sucralose (10 μg / mL), acesulfame potassium, cyclamate, sodium saccharin, aspartame, neotame, and nicotine at a wavelength of 654 nm were detected at 50 times the concentration of sucralose. Specifically, 10 μL of 10 μg / mL sucralose and 10 μL of 500 μg / mL acesulfame potassium were added to the microplate, followed by 10 μL of 5 mmol / L TMB, 10 μL of 50 mmol / L H2O2, 10 μL of 1 mg / mL neutral γ-CD-MOFs solution, and 270 μL of 0.1 mmol / L pH 4.0 acetate buffer solution. The mixture was incubated at 37 °C for 20 min, and the absorbance was measured at 654 nm. The measurements for cyclamate, sodium saccharin, aspartame, neotame, and nicotine are similar; simply replace 500 μg / mL of acesulfame potassium with an equivalent amount of 500 μg / mL of cyclamate, sodium saccharin, aspartame, neotame, or nicotine. The measurement results are as follows: Figure 9 As shown.

[0081] Figure 9 The results showed that the detection system exhibited high tolerance to coexisting substances and minimal interference was observed under the test conditions, indicating that the neutral γ-CD-MOF nanozyme has good selectivity for sucralose.

[0082] 6. Determination of sucralose in nicotine bag samples

[0083] (1) Sample preparation of nicotine bags

[0084] Nicotine pouches were used for nicotine extraction using Lost Mary's Airplane Mode Nicotine Pouches – Strawberry. 0.5 g of nicotine pouch (accurate to 0.1 mg) was accurately weighed and transferred to a 50 mL stoppered conical flask. 10 mL of deionized water was added, and the mixture was ultrasonically extracted for 30 min. The extract was centrifuged at 8000 rpm for 10 min and then filtered through a 0.22 μm filter membrane to obtain the final extract. Sucralose was added to the extract to a concentration of 3.5 µg / mL to obtain the sample solution.

[0085] (2) Detection of nicotine bag samples

[0086] Add 10 μL of the sample solution from step (1), 10 μL of 5 mmol / L TMB, 10 μL of 50 mmol / L H2O2, 10 μL of 1 mg / mL neutral γ-CD-MOFs solution, and 270 μL of 0.1 mmol / L pH 4.0 acetate buffer solution to the microplate. Mix well and incubate at 37 ℃ for 20 min. Measure the absorbance at 654 nm. Substitute the absorbance value into the regression equation in "4. Construction of Standard Curve" to calculate the concentration of sucralose in the nicotine bag sample after spiking. The results show that the measured absorbance value is 0.43078, and the calculated sucralose concentration is 3.78 µg / mL. After deducting the effect of the spiking amount, the calculated sucralose content in the nicotine bag sample is 0.23 μg / mL.

[0087] (3) Recovery and precision experiments

[0088] Two additional sucralose standard solutions of different concentrations were added to the nicotine bag samples; each concentration was measured in triplicate, the spiked recoveries were calculated, and the relative standard deviations (RSDs) were calculated. The results are shown in Table 4. The spiked recoveries of sucralose ranged from 97.0% to 102.3%, and the RSDs ranged from 2.43% to 3.71%. The method has acceptable accuracy and precision.

[0089] Table 4. Spiked recoveries and RSDs of nicotine bag samples (n = 3)

[0090] scalar Measured values Recovery rate RSD (%, n=3) 0 µg / mL 0.23 µg / mL (calculated) - 3.71 3.5 µg / mL 3.78 µg / mL 101.4% 3.09 15.5 µg / mL 15.27 µg / mL 97.0% 2.43 50 µg / mL 51.38 µg / mL 102.3% 2.78

[0091] (4) Comparative experiment

[0092] The sample solution prepared using the "(1) Nicotine bag sample preparation" method was tested according to both the "(2) Nicotine bag sample detection" method and the method in GB 5009.298-2023 "Determination of sucralose (sucralose) in food". The method in this example was compared with that in GB 5009.298-2023 "Determination of sucralose (sucralose) in food", and the results are shown in Table 5. The results show that only the method in this example can detect it, and the detection sensitivity is higher.

[0093] Table 5. Method Comparison Results

[0094] Nicotine bags (sucralose) This example method 0.23 µg / mL Values ​​measured according to GB 5009.298-2023 (HPLC method) Not detected

[0095] The method for determining sucralose established in this application has the advantages of fewer processing steps, speed and simplicity, no need for large-scale instruments and equipment as required by GB 5009.298-2023 or professional operators, short processing time, low processing cost, simple operation, and higher detection sensitivity.

[0096] The above description, in conjunction with specific embodiments, provides a further detailed explanation of this application and should not be construed as limiting the specific implementation of this application to these descriptions. Those skilled in the art to which this application pertains can make several simple deductions or substitutions without departing from the concept of this application.

Claims

1. A method for detecting sucralose, characterized in that: The sample to be tested is added to the reaction solution, acetate buffer is added, and incubation is carried out to obtain the test solution. The characteristic absorbance of the test solution is measured to obtain the absorbance detection value. The concentration of sucralose in the sample to be tested is determined based on the absorbance detection value. The reaction solution includes 3,3',5,5'-tetramethylbenzidine, H2O2, and neutral γ-CD-MOFs, wherein the neutral γ-CD-MOFs are cyclodextrin metal-organic frameworks constructed from γ-cyclodextrin and potassium ions.

2. The method according to claim 1, characterized in that: The absorbance detection value is the characteristic absorbance of the test liquid at 654 nm.

3. The method according to claim 1, characterized in that: The incubation temperature is 37°C; And / or, the incubation time is 20 min to 30 min.

4. The method according to claim 1, characterized in that: The concentration of sucralose in the sample to be tested is determined based on the absorbance detection value, specifically including: Obtain the absorbance analysis regression equation, wherein the absorbance analysis regression equation is obtained based on the sucralose concentration of several standard samples and the corresponding absorbance detection values ​​of several standard samples; The concentration of sucralose in the test sample is determined based on the absorbance detection value of the test solution and the absorbance analysis regression equation.

5. The method according to claim 4, characterized in that: The regression equation for the absorbance analysis is: y = 0.001[Sucralose] + 0.427 Where sucralose is the concentration of sucralose, and y is the absorbance value detected by light. And / or, the absorbance analysis regression equation is applicable to the detection of sucralose concentrations in the range of 3.13 μg / mL to 250 μg / mL.

6. The method according to claim 1, characterized in that: In the reaction solution, the concentration of the neutral γ-CD-MOFs is 1 mg / mL, the concentration of 3,3',5,5'-tetramethylbenzidine is 5 mmol / L, and the concentration of H2O2 is 50 mmol / L. And / or, the pH of the acetate buffer is 4; And / or, the concentration of the acetate buffer is 0.1~0.2 mol / L.

7. The method according to any one of claims 1 to 6, characterized in that: The method further includes preparing the neutral γ-CD-MOFs before adding the sample to the reaction solution: γ-cyclodextrin and KOH were added to deionized water and dissolved completely. Methanol was then added to obtain a mixture. The mixture was then placed in a sealed container containing methanol. The methanol in the container was evaporated and diffused into the mixture. The mixture was centrifuged, and the supernatant was collected. Cetyltrimethylammonium bromide was added, and the solution was mixed. The mixture was incubated overnight at room temperature. The mixture was centrifuged, and the precipitate was collected, washed, and dried to obtain basic γ-CD-MOFs. The alkaline γ-CD-MOFs were dissolved in anhydrous ethanol and glacial acetic acid, stirred and mixed evenly, centrifuged, the precipitate was collected, washed and dried to obtain the neutral γ-CD-MOFs.

8. A kit for detecting sucralose, characterized in that: Including neutral γ-CD-MOFs.

9. The reagent kit according to claim 8, characterized in that: It also includes at least one of 3,3',5,5'-tetramethylbenzidine, H2O2, acetate buffer solution, and sucralose standards of known concentration.

10. The use of the kit according to claim 8 or 9 in the detection of sucralose in atomized matrix or oral products.

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