LIMIT OF DETECTION: 10 ppb
RapidAssay 2,4-D test kits. RapidAssay 2,4-D sample diluent. Food Prep Test Kit (part number A00149). Acetone (not provided).
Because pears contain a substance that could potentially interfere with the immunoassay, an initial clean-up step must be done on pear extracts. This clean-up step may be done with the Food Prep kit. The following procedure represents a modification to the typical Food Prep Instructions in order to detect 2,4-D at 10 ppb.
1. Follow Food Prep Kit instructions for Acetone Extraction and Extract Cleanup.
2. Follow steps 6.1-6.3 for Partioning.
3. At step 7, instead of adding 50 uL of acetone extract to a test tube, add 100 uL.
4. Evaporate extract as descibed in step 8.
5. Redissolve residue in exactly 0.5 mL of 2,4-D Sample Diluent.
6. Analyze dissolved extract as the “sample” according to 2,4-D package insert.
CALCULATION OF RESULTS:
Calculate analyte concentration in pears by multiplying the assay result from the RPA-1 printout by the appropriate dilution factors.