Chapter 1, Problem 1.9P

Interpretation Introduction

Interpretation:

The concentration of pesticide has to be expressed in ppm and ppb.

Concept Introduction:

Concentrations of trace components of a sample can be expressed as parts per million (ppm) or parts per billion (ppb), terms that mean grams of substance per million or billion grams of total solution or mixture.

    $\begin{array}{l}\text{ppm}\text{=}\frac{\text{mass}\text{of substance}}{\text{mass of sample}}\text{×}{\text{10}}^{\text{6}}\\ \\ \text{ppb}\text{=}\frac{\text{mass}\text{of substance}}{\text{mass of sample}}\text{×}{\text{10}}^{\text{9}}\end{array}$