Hi,

Before extraction of biodegraded or biotransformed hydrocarbon you should take into consideration that what type of hydrocarbon you are using for degradation then consider its solubility in different solvents like polar mid polar and non polar solvents.

then through literature survey try to predict that after degradation or transformation what type of compounds will formed depending on that you should change your pH, temperature, slvent system etc etc

Regards

okay thank you

I want to extract the residual aliphatic, aromatic, and poly-aromatic hydrocarbons

The standard method for extraction poly-aromatic hydrocarbons must be decrease pH

if I decrease the pH, I lost some data for intermediate compound that I want to determine

may I decrease pH first and than increase the pH to get all of the compound?

Regards

Hi,

Decreasing pH in order to extract microbial cultures grown on hydrocarbon depends on what analytes you intend to extract from the culture.

- If your main goal is to determine the level of residual hydrocarbons in the culture you do not necessarily have to decrease the pH.

- However, If your main and only goal is to extract polar or acidic metabolites of biodegradation of hydrocarbons, you will need to decrease the pH to somewhere around pH 2 before extraction

- But if your goal is to determine the level of residual hydrocarbons as well as polar/acidic metabolites, you will first have to extract the residual hydrocarbons in the culture (with a solvent like dichloromethane) without reducing the pH, and after this you have to separate the extract containing the residual hydrocarbons from the culture supernatant. Once the latter is done, you will reduce the pH (2) of the supernatant and then extract the polar/acidic metabolic products with organic solvent like ethyl acetate.