LIMIT OF DETECTION: 0.15 ppm
RANGE OF DETECTION: 0.15 to 45 ppm
MATERIALS: Captan RaPID AssayÒ Kit and Sample Diluent Reagents: acetone and methanol (pesticide grade), distilled or deionized water. Equipment: Waring blender, 60 mL widemouthed jars with lids, magnetic stirrer, vacuum filter device, vacuum manifold, reservoirsa,d aptors, stopcocks,W hatman No.4 filter paper, BAKERBONDÔ spe octadecyl (C18) 500mg extraction column (cat. no. 7020-03), 10 mL volumetric pipet and 50 mL flask.
SAMPLE PREPARATION: Pit and weigh 3-5 peachest otalling approximately 500 grams. Blend fruit Win aring blender to a uniform mixture. Remove a 10sgu bsample to aw idemouthed jar.
EXTRACTION PROCEDURE: Add 20mL of acetone to 10g of the peach mixture and stir vigorously using a magnetic stirrer for 15 minutes so that a uniform suspension is obtained. Cover the jar with its lid while stirring. Aggregates of tissue must be broken u p .Vacuum filter the mixture throughW hatman No.4 filter paper. Collect filtrate.
CONCENTRATION PROCEDURE: Set up spe column assembly. Condition C18 column with 12 mL methanol followed
by 12 mL water. DO NOT ALLOW COLUMN TO RUN DRY.
Using a volumetric pipet, transfer exactly 10 mL of the acetone filtrate into 40 mLw oaft er. With the vacuum off, add approximately 2 mL of sample to the column. Begin aspiration of the sample at 7.5 mL/min or less. Add the remaining sample gradually. Wash the column with 6 mL water. Dry under vacuum for 3 minutes. Remove the reservoir and adapter.
Elute captan from column with three aliquots of methanol, one mL each. Adjust finavlo lume to 3 mL with methanol. Vortex to mix thoroughly.
ANALYSIS: Dilute the methanole luate 1:25 in 'cold' (4-8oC) Captan Sample Diluent (0.2 mLe luate + 4.8 mL diluent). Analyze diluted extract according to package insert for the Captan RaPID Assay.