This is defined as \[K = \frac{Q_{\text{T}}/Q_{\text{M}}}{Q_{\text{T}}^{\text{o}}/Q_{\text{M}}^{\text{o}}}\] where Q T and Q T o are the quantities of the microcomponent in the concentrate and in the sample, respectively (mass units or concentration units), and Q M o and Q M and are the quantities of the matrix before and after preconcentration, respectively. If the recovery is 100%, K = QMo/QM. The terms enrichment coefficient and enrichment factor are not recommended.