Dear Geoffery,

You have to optimize some procedure for your specific requirement. However i am suggesting a fast sonicator based method and a slow batch method. the suggested methods are ecofriendly and involve non toxic solvents and no energy expense. Distillation can always be a choiced method  of plant pigments  for extraction,however it is environmentally less viable and energy intensive.

please see the attached literature also as pdf also

I] Procedure for sonicator method:

In this method  take 10 gm of natural source i.e. flaked rose flower petals and 100ml of water. Keep the batch at 45°C for sonication for about 2 hour and then filter . After filtration analysis of dye can be done on UV spectrophotometer to find out maximum absorbance for maximum wavelength. In place of water, pure ethanol or water ethanol mixture can also be used, ethanol shall be the optimum solvent for extraction. The use of toxic organic solvents is discouraged even though they can do better extractions.

Another procedure can be Day batch method

Procedure for day’s batch method:

In this method take 10 gm of natural source i.e. flaked rose flower petals and 200ml of solvent. Solvent used can be distilled water/ ethanol with slow magnetic stirring  Make two different batches  crushed and uncrushed rose flower petals. Temperature chosen can be room temperature keep time as changing parameter. Time duration of 10 days, 15 days, 20 days, and 25 days can be attempted for maximum extraction after filtration  estimation of dye can be done on UV spectrophotometer using Beer's Lambert law. 

Dear Geoffery,

You have to optimize some procedure for your specific requirement. However i am suggesting a fast sonicator based method and a slow batch method. the suggested methods are ecofriendly and involve non toxic solvents and no energy expense. Distillation can always be a choiced method  of plant pigments  for extraction,however it is environmentally less viable and energy intensive.

please see the attached literature also as pdf also

I] Procedure for sonicator method:

In this method  take 10 gm of natural source i.e. flaked rose flower petals and 100ml of water. Keep the batch at 45°C for sonication for about 2 hour and then filter . After filtration analysis of dye can be done on UV spectrophotometer to find out maximum absorbance for maximum wavelength. In place of water, pure ethanol or water ethanol mixture can also be used, ethanol shall be the optimum solvent for extraction. The use of toxic organic solvents is discouraged even though they can do better extractions.

Another procedure can be Day batch method

Procedure for day’s batch method:

In this method take 10 gm of natural source i.e. flaked rose flower petals and 200ml of solvent. Solvent used can be distilled water/ ethanol with slow magnetic stirring  Make two different batches  crushed and uncrushed rose flower petals. Temperature chosen can be room temperature keep time as changing parameter. Time duration of 10 days, 15 days, 20 days, and 25 days can be attempted for maximum extraction after filtration  estimation of dye can be done on UV spectrophotometer using Beer's Lambert law. 

You can soak 10g of  petal  powder in 200 mL of distilled water and left for overnight. Then, the extract is heated (up to 60 0C) for 1-2 hr(s) to get a water soluble dye solution. Then, the extract is filtered.

Thank you Hassan  for your answer after the extraction how is going to be applied on fabric to stick without being washed away. What is the right non-toxic mordant to use.

Dear Geoffrey Onserio Nyamagwa, 

Lion share natural dye molecules are anionic that why it is very crucial to select proper crosslinker/ mordants. Habitually metallic salts are used but the uses of metal salts are problematic because the substantial amount of metallic salts remain unreacted in the mordanting bath. Those residual metals lead environmental hazard.  Additionally, the trace metals onto fabric prone to migrate in sweat and afterward cause various skin problems. Please check the below articles for clarification. 

http://journals.sagepub.com/doi/abs/10.1177/0040517516639816

http://www.sciencedirect.com/science/article/pii/S2213343716302305

That's why it is necessary to use alternative novel mordanting agents like tannic acid, natural mordants, etc. Additionally, cotton can be pre-cationized by chitosan. 

You get more information from here 

https://www.researchgate.net/post/How_can_we_improve_the_wash_fastness_of_cotton_fabric_dyed_with_natural_dye/1

Best regards for your research!