RANGE OF DETECTION: 0.5% to 1.5%
InQuest OP/Carbamates 25-Test Screening Kit (Item #A00122) Wash Solution B for Organophosphates (Item #A00126) Universal Range Extension Kit (Item #A00235) Eppendorf Adjustable Volume Pipette, 0.5 to 2.5 mL (Item #A00238) Glass vials, 10 mL minimum capacity
Add 6.25 mL of Wash Solution B to a glass vial using the Adjustable Volume Pipette. Set the pipette to deliver 2.5 mL and add 2 x 2.5 mL aliquots. Set the pipette to deliver 1.25 mL and add 1 x 1.25 mL aliquot. Add 25 mL of the sample to the 6.25 mL of Wash Solution B (250-fold dilution). Add 2.5 mL of Wash Solution B to a 5 mL glass vial from the Range Extension Kit using the Adjustable Volume Pipette set at 2.5 mL. Add 25 mL of the previous 250-fold dilution to the 2.5 mL of Wash Solution B (100-fold dilution).
Follow Assay Procedure in the Product Insert using the above final 100- fold dilution as “sample” in step 3 of the protocol. Please read and follow all Procedural Notes and Precautions described in the product insert.
The Negative Control and any sample that has no detectable chlorpyrifos (<0.5% using this procedure) will develop a dark blue or blue/green color. Any sample with detectable chlorpyrifos will have reduced color development compared to the negative control (i.e. the lighter the color, the more chlorpyrifos present in the sample). Following this procedure, 0.5% chlorpyrifos formulations should have lighter color development than the Negative Control, 0.75% chlorpyrifos formulations will produce less color development than the 0.5% formulations and 1.5% formulations will have minimal color development.
Due to the magnitude of the dilution used, the accuracy of the final result will depend on the care taken in making dilutions. If the Negative Control does not develop blue or blue/green color, the test is invalid and should be repeated.