b. ** Calculation. **The following sample problems will illustrate the derivation

and use of the formula for mixing liquid concentrates with liquid diluents or solid

(powder) concentrates with solid (powder) diluents:

(1) Problem #1. 55 gallons of 1% diazinon emulsion are to be prepared

using diazinon, 48% emulsifiable concentrate and water. How many gallons of the

concentrate are required?

(a)

Figure 2-3 illustrates the problem graphically.

Notation:

Q = **Quantity **of concentrate in gallons or pounds (must be same units as A).

C = **Concentration **of toxicant in the concentrate in percent.

A = **Amount **of final formulation desired in gallons or pounds (must be same

units as Q).

S = **Strength **of final formulation in percent of active ingredient.

Figure 2-3. Volumetric calculations.

(b) Computation. The one element that will remain constant

throughout the problem is the actual amount of toxicant involved. When we dilute a

pesticide, we do not change the amount of toxicant. We merely add enough diluent so

that the final formulation will consist of the desired percentage of toxicant. The amount

of toxicant in either the concentrate or the final solution is determined by multiplying the

amount of concentrated or formulation by the percentage of toxicant. Thus:

MD0173

2-8

Integrated Publishing, Inc. |