Identification of licorice herbs
Herbal identification Shape identification (1) Cross section of this product: The cork layer is a series of brown cells. The cortex is narrow. The phloem rays are broad, curved, often with fissures; the fibers are bundled, non-ligninized or micro-lumbered, and the surrounding parenchyma cells often contain calcium oxalate crystals; the sieve group often deforms due to compression. The formation of layers within the beam is obvious. Xylem ray width 3 to 5 columns of cells; more catheters, diameter of about 160μm; wood fiber bundles, surrounding parenchyma cells also contain calcium oxalate crystal. Roots are unmyelinated; roots are medullary. Powder pale brown. Fiber bundles, diameter 8 ~ 14μm, wall thickness, micro-wood, surrounding parenchyma cells containing calcium oxalate crystals, the formation of crystal fiber. Calcium oxalate crystals are more common. Trabeculae with large pits and rare textured catheters. Cork cells red-brown, polygonal, slightly woody. (2) Take this product powder 1g, add ether 40ml, heat reflux for 1 hour, filter, dregs add methanol 30ml, heat reflux for 1 hour, filter, the filtrate evaporated, the residue add water 40ml to dissolve, with n-butanol extraction 3 times, 20 ml each time, the n-butanol solution was combined, washed with water 3 times, evaporated to dryness, and 5 ml of methanol was added to dissolve the residue as a test solution. Another licorice reference drug 1g, with the legal system as a reference drug solution. Then take the ammonium glycyrrhizate control, add methanol to make a solution containing 2 mg per 1 ml as the reference solution. According to the thin layer chromatography (Appendix VI B) test, absorb 1~2μl of each of the above three solutions, and place them on the same silica gel G thin plate prepared with 1% sodium hydroxide solution, with ethyl acetate - formic acid - ice. Acetic acid-water (15:1:1:2) was used as a developing agent, developed, removed, air-dried, sprayed with 10% ethanolic sulphuric acid solution, heated at 105°C until the spots were clearly colored, and viewed under a UV lamp (365 nm). . In the chromatogram of the test sample, fluorescent spots of the same color were observed at positions corresponding to the chromatograms of the control herbs; the same orange-yellow fluorescent spots were observed at the positions corresponding to the chromatogram of the reference substance. Physical and chemical identification 1. Take this product powder on a white porcelain plate, add 80% (V/V) sulfuric acid to a few drops, yellow, gradient yellow orange (glycyrrhizin reaction). Thin layer chromatography TLC Sample solution: Take 1g of this product powder, add ether 40ml, heat to reflux for 1 hour, filter, add 30ml of dregs plus methanol and reflux for 1 hour, filter, dry the filtrate, add 40ml of water to dissolve the residue, and extract 3 times with saturated n-butanol. The extracts were combined, washed with water three times, evaporated to dryness, and the residue was dissolved in 2 ml of methanol. Control liquid: Glycyrrhizic acid plus methanol made of 2mg solution per 1ml. Expand: Silica gel G thin plate, spotting 5 (l, with ethyl ester-formic acid-glacial acetic acid-water (30:2:2:4) as developing agent, exhibition distance 8cm. Color development: ethanolic sulfuric acid spray, heated at 105 °C, UV lamp (365nm) under the examination, the test solution chromatography in the corresponding position with the reference solution chromatography, the same color spots. Determination of content According to HPLC: 1. Chromatographic conditions and system suitability test: octadecylsilane-bonded silica gel as a filler; methanol-0.2mol/L ammonium acetate solution with glacial acetic acid (67:33:1) as the mobile phase; detection wavelength at 250nm . The number of theoretical plates should not be less than 2000 according to the monoammonium salt peak of glycyrrhizic acid. 2. Preparation of reference solution: take about 10mg of glycyrrhetic acid monoammonium salt reference substance, accurately weighed, set it into a 50ml volumetric flask, dissolve it with mobile phase and dilute it to the mark, shake well, that is to say (each glycyrrhizic acid containing 1ml) Ammonium salt control 0.2 mg, 0.1959 mg of glycyrrhizic acid). 3. Preparation of the test solution: take about 0.3g of this product powder, accurately weighed, set the 50ml volumetric flask, add mobile phase about 45ml, ultrasonic treatment (power 250W, frequency 20kHz) for 30 minutes, remove, let cool, Add mobile phase to the scale, shake, filter, that is, too. 4. Assay method: Each 10 μl of the reference solution and the test solution was accurately pipetted and injected into the liquid chromatograph. Advantages and Disadvantages For the inspection of the Chinese medicine market, there are problems such as sulphur smoke, bacteria, and heavy metals exceeding the standard in the licorice on the market, failing to meet medical requirements, and even producing counterfeit goods, posing as licorice for sale. Identification of licorice points are four: First, the root cylindrical, reddish-brown or gray-brown; Second, with vertical groove wrinkles and lenticels; Third, solid quality, yellow-white cross-section, the formation of ring ring pattern is obvious; Fourth, gas micro, special Sweet taste. The similar products of Glycyrrhiza licorice are fine and inconspicuous, with firm quality, less cracks in cross section and sweet taste; while the licorice inflated has thick roots and rhizomes, grayish brown or brown, and it is hard, powdery, sweet or with bitter. As for the yellow licorice, crude licorice root bar is fine, sweet taste is slightly worse; thorn licorice, bitter licorice is bitter, can be distinguished. LH Ovulation Test Strip,Ovulation Test for Women, Ovulation Rapid Test Kit,LH Ovulation Test Kit Devices Weihai Kangzhou Biotechnology Engineering Co.,Ltd , https://www.weihaikangzhou.com