procedures
preparation : mixed 1 g of chicken in a blender , add 3 ml of water and 25 ml 10 ppb IS , the portion is centrifudged for 5 minutes (3000rpm) .
Take supernatant in new centrifudge tube , add DI water 10 ml and Hexane 10 ml then centrifuge for 15 minutes
Seperate outer lipid layer , add ethyl acetate 5 ml and centrifudge for 15 minutes . Evaporate with nitrogen flow at50.... then add DI water 5 ml and shake
Condition :
condition the Vertipak c18 tubes with methanol 3 ml at flow rate 5 ml/min
Loading : add sample to vertipak c18 tubes apply vacuum at flow rate 1 ml/min
washing : after extraction of sample is carried out , add methanol DI water 10:90 for washing and apply vacuum at 5 ml/min
Elute : elute the analytes from tubes with methanol 3 ml apply vacuum at flow rate 1 ml/min into 10 ml centrifuge tube.
Drying : evaporate with nitrogen flow at.. add methanol di water 50:50 then vortex. Filter into vial for HPLC analysis.