I have to extract norethindrone from Hoagland nutrient solution and plant tissue with solid phase extraction. But I found 2 different cartridges : C18 (common reversed phase extraction) and SI (common normal phase extraction; potential to extract polar compound from non-polar solution) in my laboratory. Usually cartridge Oasis HLB is frequently applied in previous articles (but yet when it shown less studies on norethindrone extraction and extraction). Is that norethindrone is polar? Is that availability of norethindrone extraction with cartridge SI? Thanks