... present in those samples In a biplot, the length of the lines approximates the variances of the variables The longer the line, the higher is the variance Inferring from Figure 3. 7, 3- nitroaniline ... depends on the axes and the points As for the points, the `quality' of the PCA approximation is found from the R program In this case, the quality 0.627 implies that 62.7% of the variation in the samples ... was maintained at a constant flow of 0.5mL min−1 Injection volumes of 3mL were used The injection port was held at 230 ˚C and used in the splitless mode, applying a pressure pulse of 40 psi The...