RANGE OF DETECTION: 44 to 600 ppb
Chlorpyrifos RaPID AssayÒ Kit and Sample Diluent. RaPID Prep Ô Food Prep Kit. Reagents: acetonitrile (pesticide grade). Equipment: commercial food processor or blender (or equivalent) with acetonitrile resistant container cup, 18 x 150 mm glass test tubes, serological pipets, micropipet (100 mL), vortex mixer, centrifuge (optional), scale or balance.
SAMPLE PREPARATION: Weigh a banana finger to the nearest gram. Thinly slice the finger.
Transfer sliced finger to blender. Add a volume (in mL) of acetonitrile equivalent to two times the weight (in grams) of the finger, i.e., 50 gram finger plus 100 mL acetonitrile. Process sample/solvent to a homogenous consistency. Allow solids in the homogenate to settle for 30 minutes. If banana solids do not settle easily, centrifuge gently at approximately 1000 rpm for 2-3 minutes. Transfer approximately 4 mL of the acetonitrile extract (upper layer) to an Extract Cleanup Reagent Tube from the Food Prep Kit. Vortex the tube for 15 seconds. Using the scoop provided in the kit, add one scoopful of Salt Reagent to the tube. Cap the tube and vortex to mix thoroughly. Allow the aqueous and acetonitrile phases to separate for about 5 minutes.
Carefully transfer 100 mL of the acetonitrile phase (top layer) to a test tube containing 10 mL of Chlorpyrifos Sample Diluent (a 1:100 dilution). Analyze the diluted extract as the 'sample' according to package insert of the RaPID Assay.