Method for detecting permanganate in water samples using ginger carbon quantum dots
By using ginger carbon quantum dots as fluorescent probes, the content of permanganate in water samples was measured, and the problems of cumbersome and long time in the prior art were solved, and rapid, sensitive and highly selective permanganate detection was achieved.
Patent Information
- Application Number
- CN202210978758.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-08-16
- Publication Date
- 2025-05-06
- Estimated Expiration
- 2042-08-16
AI Technical Summary
The existing permanganate analysis and assay technology has problems such as cumbersome pretreatment process and long analysis time, and lacks a simple, fast, high sensitivity and good selectivity detection method.
The ginger carbon quantum dots were used as fluorescent probes to prepare a standard aqueous ginger carbon quantum dot solution, and the fluorescence spectrum was measured in the presence of different concentrations of permanganate, a standard curve was established, and the concentration of the permanganate solution to be measured was calculated.
It has achieved rapid and sensitive detection of the content of permanganate in water samples, with a detection limit of 0.059mol/L, and the ginger carbon quantum dot probe has the characteristics of low toxicity, low cost, good fluorescence stability and environmentally friendly.
Smart Images
Figure CN115479926B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of chemical detection, and in particular to a method for detecting permanganate in a water sample by utilizing ginger carbon quantum dots. Background Art
[0002] Manganese is a major trace element for human health and is essential for growth, metabolism and anti-oxidation. As a chemical oxidant, permanganate is relatively stable, easy to handle and relatively low in cost. It is a key element in controlling taste, odor compounds and algal toxins. - ) and the formation of disinfection by-products in the water supply process have received widespread attention. However, excessive absorption of permanganate may cause nervous system disorders, DNA mutations, depression, hallucinations, extreme weakness and permanent disability. Therefore, it is of great significance to determine the permanganate content in water samples. Current permanganate analysis and determination techniques include redox titration, atomic absorption spectroscopy, electrochemistry, spectrophotometry, etc., but these methods have the characteristics of cumbersome pre-treatment process and long analysis time. There is an urgent need for a simple, rapid, highly sensitive and highly selective method to detect the permanganate content in water samples.
[0003] The comparative document "Study on the Chemiluminescence Mechanism of Fluorescent Carbon Quantum Dots and Potassium Permanganate" explored the situation where potassium permanganate increases the luminescence intensity of fluorescent carbon quantum dots based on the chemiluminescence mechanism of fluorescent carbon quantum dots and potassium permanganate. However, due to the different particle sizes of carbon quantum dots, the fluorescence properties are also different, so there is a situation of carbon quantum dot fluorescence quenching. However, there are few reports on the existing technology about the method of using biomass carbon quantum dot fluorescence quenching to detect permanganate in water samples. Summary of the invention
[0004] In order to solve the problems existing in the background, the present invention provides a method for detecting permanganate in a water sample using ginger carbon quantum dots, characterized in that the method comprises the following steps:
[0005] 1) preparing a fluorescent probe, wherein the fluorescent probe is carbon quantum dots prepared from ginger as a raw material, and preparing a standard ginger carbon quantum dot aqueous solution, wherein the mass concentration of the ginger carbon quantum dots is 0.60 mg / mL;
[0006] 2) taking the same volume of standard ginger carbon quantum dot aqueous solution, adding the same volume and different concentrations of permanganate standard solution to each ginger carbon quantum dot aqueous solution, and measuring the emission spectrum by fluorescence spectroscopy, wherein the excitation wavelength of the emission spectrum is 410 nm and the emission wavelength range is 430-700 nm; establishing a standard curve to record the fluorescence intensity, wherein the standard curve uses the fluorescence intensity as the ordinate and the permanganate solution concentration as the abscissa;
[0007] 3) Take the same volume of the permanganate solution to be tested as the permanganate standard solution, add it to the same volume of the standard ginger carbon quantum dot aqueous solution, measure the fluorescence intensity by fluorescence spectroscopy, and calculate the concentration of the permanganate solution to be tested in combination with the drawn standard curve.
[0008] Optimally, the preparation method of ginger carbon quantum dots in step 1) is to use ginger as raw material, grind it into powder after drying, weigh 0.5g of ginger powder and mix it with 10-16mL of distilled water, place it in a 20mL polytetrafluoroethylene-lined high-pressure reactor, react at 150-250℃ for 8-15h, filter after cooling, purify, and freeze-dry to obtain ginger carbon quantum dot powder. Ginger carbon quantum dot probes have the characteristics of low toxicity, low cost, good fluorescence stability, and environmental friendliness. If ginger juice is used as the carbon source to detect potassium permanganate, the material characterization results show that the optimal excitation wavelength of the purified ginger juice carbon quantum dots is 370nm and the emission wavelength is 450nm, while the ginger carbon quantum dots used in the present invention have an optimal excitation wavelength of 410nm and an emission wavelength range of 430-700nm. Compared with the two, ginger juice is suitable for detecting I in water. - ions, while ginger powder carbon quantum dots have the characteristics of simple preparation, low cost, good fluorescence stability, and environmental friendliness, and are more suitable for detecting MnO4 in water. - ion.
[0009] In addition, the mass concentration of ginger carbon quantum dots used in the present invention is 0.60 mg / mL. At this concentration, the fluorescent probe has a fast detection speed, high sensitivity, and good selectivity, and can detect permanganate in the sample. When the mass concentration of ginger carbon quantum dots is 0.60 mg / mL, the change in its fluorescence spectrum is most significant. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 The fluorescence spectra of carbon quantum dots under different mass concentration conditions.
[0011] Figure 2 The standard curve of the permanganate standard solution obtained when the excitation wavelength is 410nm with ginger carbon quantum dots as the fluorescent probe, wherein the ordinate is the fluorescence intensity of ginger carbon quantum dots and the abscissa is the emission wavelength, in nm. DETAILED DESCRIPTION
[0012] Example 1: Prepare a standard ginger carbon quantum dot aqueous solution, wherein the concentration of ginger carbon quantum dots is 0.60 mg / mL, add permanganate solution to the ginger carbon quantum dot aqueous solution, the concentration is 1×10 -4 mol / L、2×10 -4 mol / L、3×10 -4 mol / L、4×10 -4mol / L、5×10 -4 mol / L、6×10 -4 mol / L、7×10 -4 mol / L、8×10 -4 mol / L、9×10 -4 mol / L、1×10 -3 mol / L, at an excitation wavelength of 410nm and an emission wavelength range of 430-700nm, the fluorescence spectrum was measured and a, b, c, d, e, f, g, h, i, j were obtained in sequence. Figure 2 It can be seen that the fluorescence intensity of ginger carbon quantum dots decreases with the increase of the concentration of permanganate solution, and the fluorescence intensity value has a good linear relationship with the concentration of permanganate solution. 2 =0.991. It can be seen that the detection limit of permanganate using ginger carbon quantum dots as a fluorescent probe is 0.059 mol / L.
[0013] As a verification of this method, five water samples, 1#, 2#, 3#, 4# and tap water from different areas of Dianchi Lake in Kunming, Yunnan, were tested. The five water samples were filtered and boiled for 30 minutes, and filtered with a 0.22μm filter membrane to avoid interference from microorganisms. The standard addition method was used to add the standard sample to the actual sample, and the recovery rate of permanganate in the actual water sample was determined. The results are shown in the following table:
[0014] Table 1 Results of spiked recovery test of permanganate in actual water samples
[0015]
[0016] The recovery rate determined by this method is 94.72% to 113.36%, and the relative standard deviation RSD is 0.57% to 3.33%. The results show that this method can be used to detect permanganate in actual water samples. Generally speaking, the concentration range of potassium permanganate solution is 0 to 1000 μmol / L.
Claims
1. A method for detecting permanganate in water samples using ginger carbon quantum dots, characterized in that The method comprises the following steps: A fluorescent probe is prepared, wherein the fluorescent probe is carbon quantum dots prepared from ginger as a raw material, and a standard ginger carbon quantum dot aqueous solution is prepared, wherein the mass concentration of the ginger carbon quantum dots is 0.65 mg / mL; Take the same volume of standard ginger carbon quantum dot aqueous solution, add the same volume and different concentrations of permanganate standard solution to each ginger carbon quantum dot aqueous solution, and use fluorescence spectroscopy to measure the emission spectrum, the optimal excitation wavelength of the emission spectrum is 410 nm, and the emission wavelength is 503 nm; establish a standard curve to record the fluorescence intensity, the standard curve uses the fluorescence intensity as the ordinate and the permanganate solution concentration as the abscissa; Take the same volume of the permanganate solution to be tested as the permanganate standard solution, add it to the same volume of the standard ginger carbon quantum dot aqueous solution, measure the fluorescence intensity by fluorescence spectroscopy, and calculate the concentration of the permanganate solution to be tested in combination with the drawn standard curve.
2. A method for detecting permanganate in a water sample using ginger carbon quantum dots as claimed in claim 1, characterized in that In step 1), the preparation method of ginger carbon quantum dots is as follows: ginger is used as raw material, dried and ground into powder, 0.5 g of ginger powder is weighed and mixed with 10-16 mL of distilled water, and then placed in a 20 mL polytetrafluoroethylene-lined high-pressure reactor, reacted at 150-250° C. for 8-15 h, filtered after cooling, purified, and freeze-dried to obtain ginger carbon quantum dot powder.