Source: Encyclopedia of Life (Smithsonian Institution, National Museum of Natural History, Department of Botany)^[1]

Method

Test Sample Preparation: 1 g of ground plant material into a Soxhlet thimble and extractovernight with about 90 ml of acetone, centrifuge and use the supernatant. Dilute the extract 1:10 in acetone and mix well. Before injection, filter through a 0.20 um PTFE membrane filter.

Column: 100-mm x 2.1-mm, 1.7 um, Waters Acquity BEH C18

Mobile Phase: 0.1% formic acid in water (Solution A) and acetonitrile (Solution B)

Elution: Gradient, see Table below

Column Temperature: 70°C

Flow rate: 0.6 mL/min

Detection: Vis, 426 nm

Injection volume: 1.0 uL, maintained at 10°C

Needle wash: Acetonitrile

System suitability: Curcumin peak, tailing 0.8 to 1.5

Source: Indena S.p.A. ^[12]

Method

Test Sample Preparation: 1 g of ground plant material into a Soxhlet thimble and extract overnight with about 90 ml of acetone, centrifuge and use the supernatant. Dilute the extract 1:10 in acetone and mix well. Before injection, filter through a 0.20 um PTFE membrane filter.

Column: 25-cm x 4.6-mm, 5 um, Waters Symmetry C18

Mobile Phase: 0.3% acetic acid in water (Solution A) and acetonitrile (Solution B)

Elution: Gradient, see Table below

Column Temperature: 35°C

Flow rate: 1.0 mL/min

Detection: Vis, 426 nm

Injection volume: 10 uL

System suitability: Curcumin peak, tailing 0.8 to 2.0; resolution between demethoxycurcumin and curcumin is ≥ 2.0

Source: Indena S.p.A. ^[13]

Turmeric (rhizome) HPTLC ID - White RT

Turmeric (rhizome) (Curcuma longa)

Lane Assignments Lanes, from left to right (Track, Volume, Sample):

1. 2 µL Bisdesmethoxycurcumin
2. 2 µL Desmethoxycurcumin
3. 2 µL Curcumin
4. 4 µL Curcuminoids
5. 2 µL Turmeric (Curcuma longa)
6. 2 µL Curcuma xanthorrhiza 

Reference Sample(s) Reference: Dissolve 2 mg of USP Curcuminoids RS in 5 mL of methanol. 

Stationary Phase Stationary phase, i.e. Silica gel 60, F254 

Mobile Phase Toluene, acetic acid (4:1) (v/v) 

Sample Preparation Method Sample: Mix 0.2 g of powdered sample with 3 mL of methanol, sonicate for 10 minutes, then centrifuge or filter the solution and use the supernatant/filtrate as test solution. 

Detection Method Saturated chamber; developing distance 70 mm from lower edge; relative humidity 33% 

Other Notes Images presented in this entry are examples and are not intended to be used as basis for setting specifications for quality control purposes.

System suitability test (UV 366 nm): Curcuminoids: three yellowish-green zones at Rf ~ 0.21 (bisdesmethoxycurcumin), Rf ~ 0.32 (desmethoxycurcumin), and Rf ~ 0.42 (curcumin).

Identification: Compare result with reference images. The fingerprint of the test solution is similar to that of the corresponding botanical reference sample. Additional weak zones may be present. The chromatogram of the test solution shows three yellowish-green zones at Rf ~ 0.21, Rf ~ 0.32, and Rf ~ 0.42 corresponding to the three zones of the curcuminoids reference.

Test for other species: The chromatogram of Curcuma xanthorriza does not show an intense fluorescent zone at Rf ~ 0.21 (orange arrow).

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  Turmeric (rhizome) HPTLC ID - White RT

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  Turmeric (rhizome) HPTLC ID - UV 366 nm

Source: HPTLC Association ^[14]

Turmeric adulteration with nimesulide (rhizome) HPTLC ID - UV 254 nm

Turmeric adulteration with nimesulide (rhizome) (Curcuma longa)

Lane Assignments Lanes, from left to right (Track, Volume, Sample):

1. 2 µL Curcuma longa rhizome 1 (not spiked)
2. 2 µL Curcuma longa rhizome 1 (spiked w/ 1% nimesulide)
3. 2 µL Curcuma longa rhizome 1 (w/ 2% nimesulide)
4. 2 µL Curcuma longa rhizome 1 (w/ 5% nimesulide)
5. 2 µL Curcuma longa rhizome 1 (w/ 10% nimesulide)
6. 2 µL Curcuma longa rhizome 2 (not spiked)
7. 2 µL Curcuma longa rhizome 2 (w/ 1% nimesulide)
8. 2 µL Curcuma longa rhizome 2 (w/ 2% nimesulide)
9. 2 µL Curcuma longa rhizome 2 (w/ 5% nimesulide)
10. 2 µL Curcuma longa rhizome 2 (w/ 10% nimesulide)
11. 2 µL Curcuma longa rhizome 3 (not spiked)
12. 2 µL Curcuma longa rhizome 3 (w/ 1% nimesulide)
13. 2 µL Curcuma longa rhizome 3 (w/ 2% nimesulide)
14. 2 µL Curcuma longa rhizome 3 (w/ 5% nimesulide)
15. 2 µL Curcuma longa rhizome 3 ( w/ 10% nimesulide) 

Reference Sample(s) Reference: Dissolve 1.0 mg of nimesulide in 10 mL of methanol. 

Stationary Phase Stationary phase, i.e. Silica gel 60, F254 

Mobile Phase Toluene, acetic acid (4:1) (v/v) 

Sample Preparation Method Sample: Mix 0.2 g of powdered sample with 3 mL of methanol, sonicate for 10 minutes, then centrifuge or filter the solution and use the supernatant/filtrate as test solution.

Derivatization reagent: 2,5-Dichloro-1,4-benzoquinone reagent, Preparation: 0.50 g of 2,5-Dichloro-1,4-benzoquinone is dissolved in 80 mL of dimethyl sulfoxide and then diluted with 160 mL of tetrahydrofuran, Use: Dip (time 0, speed 5), dry in a stream of cold air for 3 min. 

Detection Method Saturated chamber; developing distance 70 mm from lower edge; relative humidity 33% 

Other Notes Images presented in this entry are examples and are not intended to be used as basis for setting specifications for quality control purposes.

System suitability test: Nimesulide: Rf ~ 0.51

Test for adulteration: Compare result with reference images. The fingerprint of the test solution is similar to that of the corresponding botanical reference sample. Additional weak zones may be present. The chromatogram of the test solution shows no zone at Rf ~ 0.51 corresponding in color and position to that of the nimesulide reference standard.

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  Turmeric adulteration with nimesulide (rhizome) HPTLC ID - UV 254 nm

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  Turmeric adulteration with nimesulide (rhizome) HPTLC ID - 2,5-Dichloro-1,4-benzoquinone reagent, UV 366 nm

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  Turmeric adulteration with nimesulide (rhizome) HPTLC ID - 2,5-Dichloro-1,4-benzoquinone reagent, white RT

Source: HPTLC Association ^[15]