• Description: Brownish- yellow powder.
  • Solubility: Soluble in water.
  • Identification:
  1. Thin-layer chromatographic

Test for flavonoids

Standard solution: A solution of 0.6 mg/mL of USP Rutin RS, 0.2 mg/mL of USP Chlorogenic Acid RS, and 0.2 mg/mL of USP Quercetin RS in methanol

Sample solution: Transfer 1.0 g of finely powdered Ginkgo to a 50-mL round-bottom flask fitted with a reflux condenser. Add 10 mL of methanol, reflux in a water bath for 10 min, allow to cool to room temperature, and filter. [NOTE—Reserve some of the Sample  solution for use in the Test for terpene lactones.]

Adsorbent:   Chromatographic silica gel mixture with an average particle size of 5 µm (HPTLC plates

Application volume: 5µL

Developing solvent system: Ethyl acetate, water, anhydrous formic acid, and glacial acetic acid (100:26:11:11)

Spray reagent 1: 5 mg/mL of 2-aminoethyl diphenylborinate in methanol

Spray reagent 2: 50 mg/mL of polyethylene glycol 400 in alcohol


Samples: Standard solution and Sample solution Before development of the chromatograms, saturate the chamber for 20 min with Developing solvent system. Record temperature and humidity in the laboratory. If the relative humidity exceeds 50%, condition the plate to about 35% relative humidity using a suitable device. Apply the samples separately as bands to a suitable thin-layer chromatographic plate , and allow the bands to dry. Develop the plate oven at 1050 for 5 minute. Immediately spray the hot plate with spray reagent 1, then with spray reagent 2, dry, amd examine under long-wave length UV light.

           Acceptance criteria: The Standard solution shows in its lower part with increasing RF values

a  yellowish-brown  fluorescent zone due to rutin (RF 0.28), a light blue fluorescent zone due

to chlorogenic acid (RF 0.36) and a yellow fluorescent zone due to quercetin (RF 0.92).

The Sample solution shows a yellowish -brown fluorescent zone, a light blue fluorescent zone

,  and a yellowish brown fluorescent  zone at RF similar to those of rutin, chlorogenic acid,

and  quercetin, respectively, in  the Standard solution. Additional yellowish to yellowish

green  zones due to flavonoids  detected in the Sample  solution chromatogram include

one zone below the  rutin and chlorogenic acid zones, Other zones may be seen in the

Sample solution chromatogram.

Heavy Metals : NMT 20µg/g

  • Microbial Enumeration Tests

The total aerobic bacterial count does not exceed 105 cfu/g, the total combined molds and yeasts count does not exceed 103 cfu/g and the bile-tolerant gram negative- bacteria does not exceed 103 cfu/g.

 Absence of Specified  Micro Organisms

Meets the requirements of the tests for absence of Salmonella species and Escherichia coli.

  • Loss On Drying

Sample : 1.0 g of finely powdered Ginkgo.

Analysis : Dry the Sample at 1050  for 2 h.

Acceptance criteria: NMT 11.0%

  • Total Ash

Sample : 1.0 g of finely powdered Ginkgo.

Acceptance criteria: NMT 11.0%