Method for identifying origin of chrysanthemi flos
A method for identifying an origin of Chrysanthemi flos is provided, which belongs to the technical field of chemical analysis and detection, and comprises the following steps: mixing Chrysanthemi flos extract with aluminum ion solution, and gold nano-clusters (AuNCs) solution in a solvent, standing for reaction, detecting fluorescence intensity of Chrysanthemi flos , comparing the fluorescence intensity of Chrysanthemi flos to be detected with that of Chrysanthemi flos from a target origin, and determining whether they are from a same origin. According to the application, excited-state intramolecular proton transfer effect between 3-hydroxyflavone derivatives of Chrysanthemi flos and aluminum ions is utilized to enhance the fluorescence of 3-hydroxyflavone derivatives, where AuNCs combines aluminum ions to enhance aggregation-induced fluorescence, and reacts with flavonoids to quench their fluorescence; and visual characterization and traceability of Chrysanthemum morifolium quality are achieved by further comparing obvious rich fluorescence color changes before and after the reaction.
1. A method for identifying an origin of Chrysanthemi flos , comprising: preparing an extract of a Chrysanthemi flos to be detected;
preparing an extract of a Chrysanthemi flos from a target origin;
preparing a gold nano-clusters (AuNCs) solution with orange fluorescence;
uniformly mixing the extract of the Chrysanthemi flos to be detected, an aluminum ion solution and the AuNCs solution in a solvent, standing for reaction, detecting a fluorescence intensity of the Chrysanthemi flos to be detected after the reaction, taking photos of fluorescence color change before and after the reaction, obtaining fluorescence color change according to the photos of fluorescence color change before and after the reaction, and converting the obtained fluorescence color change into red-green-blue (RGB) data;
uniformly mixing the extract of the Chrysanthemi flos from the target origin, the aluminum ion solution and the AuNCs solution in a solvent, reacting, detecting a fluorescence intensity of the Chrysanthemi flos from the target origin after the reacting, taking photos of fluorescence color change before and after the reacting, acquiring fluorescence color change according to the photos of fluorescence color change before and after the reacting, and converting the acquired fluorescence color change into RGB data; and
comparing the RGB data of the Chrysanthemi flos to be detected with the RGB data of the Chrysanthemi flos from the target origin, and thereby identifying the origin of the Chrysanthemi flos to be detected.
2. The method for identifying the origin of Chrysanthemi flos according to claim 1 ,
wherein each of the preparing an extract of a Chrysanthemi flos to be detected and the preparing an extract of a Chrysanthemi flos from a target origin specifically comprises:
using a methanol aqueous solution as an extraction solvent, and performing ultrasonic extraction; and
wherein the preparing an AuNCs solution with orange fluorescence specifically comprises:
dropwise adding a chloroauric acid solution into a reduced glutathione solution under a stirring condition, then adjusting a pH value to be in a range of 4.5 to 5.5, and heating in a dark environment under the stirring condition to obtain the AuNCs solution with orange fluorescence.
3. The method for identifying the origin of Chrysanthemi flos according to claim 2 ,
wherein each of the preparing an extract of a Chrysanthemi flos to be detected and the preparing an extract of a Chrysanthemi flos from a target origin specifically comprises:
crushing and grinding the Chrysanthemi flos and sieving the crushed and ground Chrysanthemi flos with a 50-mesh sieve to obtain Chrysanthemi flos powder, mixing the Chrysanthemi flos powder with the methanol aqueous solution of 70% by volume according to a material-liquid ratio of 5 grams (g):1,000 milliliters (mL), then performing the ultrasonic extraction at 40 degree Celsius (° C.) for 30 minutes (min) to obtain a crude extract, centrifuging the crude extract at 8,000 revolutions per minute (rpm) for 10 min, and then taking supernatant to pass through a microporous membrane with a pore size of 0.22 microns (μm) to obtain the extract of the Chrysanthemi flos;
wherein during the preparing an AuNCs solution with orange fluorescence:
a mass fraction of chloroauric acid in the chloroauric acid solution is 1%, a concentration of reduced glutathione in the reduced glutathione solution is 0.001 g/mL, and a molar ratio of the chloroauric acid to the reduced glutathione is in a range of 1: (1.4-1.6); a sodium hydroxide solution with a concentration of 0.1 mol/L is used to adjust a pH value to 5; and
wherein the heating in a dark environment under the stirring condition specifically comprises:
heating in the dark environment at 70° C. and 1,000 rpm for 20 hours (h), centrifuging at 8,000 rpm for 10 min, and then filtering supernatant with the microporous membrane with the pore size of 0.22 μm to obtain the AuNCs solution with orange fluorescence.
4. The method for identifying the origin of Chrysanthemi flos according to claim 1 ,
wherein a concentration of the AuNCs solution is in a range of 0.8 mg/mL to 6.4 mg/mL, a concentration of the aluminum ion solution is in a range of 1 millimole/liter (mmol/L)-20 mmol/L, and a mixing volume ratio of the extract of the Chrysanthemi flos to be detected:the aluminum ion solution:the AuNCs solution is 100:50:50; and a duration of the standing for reaction is in a range of 2 min to 10 min;
wherein the solvent is ethanol; and
wherein the fluorescence intensity of the Chrysanthemi flos to be detected is under an emission wavelength of 380 nanometres (nm) to 650 nm, an excitation wavelength of 340 nm, and a slit width of 10 nm.