RANGE OF DETECTION: Chlorpyrifos: 10-500 ppb
Chlorpyrifos RaPID AssayÒ Kit and Sample Diluent. Methanol (pesticide grade). Sample Extraction Kit (call SDI for details0.
Allow frozen samples to thaw. Break up large (> 1 cm dia.) soil aggregates and mix sample thoroughly to uniformity with a mixer, mortar and pestle or by hand with a spatula or spoon. For moist samples, soil may be air dried at room temperature by spreading soil in a thin layer for up to 24 hours prior to mixing. Samples should be less than 30% moisture.
Add 20 mL of methanol to 10 g of soil in the extraction jar with BBs. Shake vigorously by hand for 1 minute. Allow soil particles to settle for approximately 15 minutes. If necessary to clarify, filter at least 0.5 mL of the extract.
Dilute the clarified extract 1:50 with the appropriate Sample Diluent using serological pipets (e.g. 0.1 mL extract plus 4.9 mL diluent). Analyze the diluted extract as the 'sample' according to package insert of the RaPID Assay.