## FORMULATION OF EVOLUER 4-4 ULV FOR THE BOTTLE BIOASSAY

PHEREC Technical Memorandum # 21

The following procedure yields permethrin at a concentration appropriate for testing insecticide resistance by means of the CDC bottle bioassay.

1. Start with the label. The label is the law.

2. According to the label one gallon of EVOLUER 4-4 ULV contains 0.29 pounds of permethrin.

3. Convert pounds/gallon to grams/liter.

4. 0.29 pounds/ 1 gallon X 453.6 grams/ 1 pound X 1 gallon/ 3.785 liters = 34.75 grams/liter.

5. Convert grams/liter to milligrams/milliliter.

6. 34.75 grams/liter X 1 gram/1000 milligrams X 1000 milliliters/ 1 liter =34.75 milligrams/ml.

7. Dilute 1 milliliter of EVOLUER 4-4 ULV in 100 milliliters A.C.S. acetone [final volume].

8. 34.75 milligrams/milliliter X 1 ml/100 ml = 0.3475 mg/ml.

9. This is the STOCK solution.

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**The STOCK solution can be stored in a light proof sealed container in the chemical storage shed until needed.

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**The TEST solution is prepared as follows:

1. Pipette 12.4 ml of the STOCK solution into a 100 ml volumetric flask.

2. Fill the volumetric flask to the 100 ml mark with A.C.S. acetone.

3. 0.3475 mg/ml X 12.4 X 1 ml/ 100 ml = 0.043 mg/ml.

4. This is the TEST solution.

5. Convert mg to micrograms.

6. 0.043 mg/ml X 1000 micrograms/ 1 milligram = 43 micrograms

Each one (1) ml of the TEST solution contains 43 micrograms of permethrin which is the diagnostic concentration.