In the first step, the sample must be extracted with a suitable solvent like methanol: chloroform, ethanol, acetonitrile, or others.
The sample must be extracted with a suitable solvent like methanol. This was in the first step. The sample must be extracted with chloroform. This was in the first step. The sample must be extracted with ethanol. This was in the first step. The sample must be extracted with acetonitrile. This was in the first step. The sample must be extracted with others. This was in the first step.