3.1.2. Linearity and limits
In the concentration ranges studied, and for all compounds, the analytical response was linear with coefficients of determination (R2) equal to or higher than 0.99; intercepts were not statistically different from zero (Table 2). The limits of detection varied between 1 mg/L (toluene and p-xylene) and 10 mg/L (chloroform) and the limits of quantification between 2 mg/L (p-xylene) and 31 mg/L (chloroform). Table 2 presents the results obtained for the LOD and LOQ of all substances.