Chlorpyrifos for the Bottle Bioassay

FORMULATION OF CHLORPYRIFOS FOR THE BOTTLE BIOASSAY

This is a draft protocol. 12/27/2006

PHEREC Technical Memorandum No 12

According to the maufacturer's LABEL:

1 gallon of MosquitoMist TwoŽ contains 1.93 lbs. chlorpyrifos [the active ingredient, abreviated = a.i.]
1 gallon = 3.785 liters
1 pound (lb.) = 453.6 grams

1.93 lbs. X 453.6 g/lb = 875.448 grams a.i. / gal. [convert to SI units]
875.448 / 3.785 = 231.294 grams / liter

1 liter of MosquitoMist TwoŽ contains 231.29 grams a.i.
1 milliliter of MosquitoMist TwoŽ contains 0.231 grams a.i.
1 milliliter of MosquitoMist TwoŽ contains 231.29 milligrams

TAKE one (1) milliliter of MosquitoMist TwoŽ and, using a volumetric flask, dilute it to 100 ml FINAL VOLUME with A.C.S. acetone. [A.C.S. acetone is the grade of acetone approved by the American Chemical Society (A.C.S.)]. This is the STOCK SOLUTION.

The STOCK solution contains 2.31 milligrams a.i./ml

TAKE 0.87 ml of the STOCK solution and dilute it to 100 ml FINAL VOLUME with A.C.S. acetone. This is the TEST solution.

2.31 X 0.87 = 2.00 milligrams ai. / ml

200.97 / 100 = 0.020 milligrams a.i. / ml

20 micrograms chlorpyrifos per 1 milliliter of A.C.S. acetone is the diagnostic dose.

The TEST solution contains 0.02 milligrams a.i. / ml
The TEST solution contains 20.0 micrograms a.i. / ml [This is the diagnostic dose]

USE 1 ml of the TEST solution in each bottle of the Bioassay.
[The detailed standardized procedure to follow is available here]

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This protocol was developed by Pam Jacobson and Jack Petersen on 11/6/2006 at Hillsborough County MCD and is currently being tested for correctness. Please check back for updates. Report any problems to Dr. Jack Petersen.

For more information, CONTACT Dr. Jack Petersen
at (850) 872-4184 extension 36 or email drjack3@hotmail.com

Please check our Website for updates on this protocol:

http://pherec.org/bottleassay/
updated on 12/27/2006 by jlp