Recycling Control of Histological Xylol: A Chemometric Approach

Fractional distillation was applied to recycle and reuse histological xylol waste. A new sample preparation technique for analyzing liquid samples by transmission FTIR spectroscopy was developed and validated. Pressing time, sample volume, and xylol volatility were the optimized variables to acquire good quality spectra by using the KBr pellet technique. The suitability of this technique for analyzing a volatile sample, xylol, was contrasted against a non‐volatile coal sample. Semi‐quantitative IR‐derived ratios were calculated and used as input variables in principal components analysis (PCA). One‐way analysis of variance (ANOVA) test was applied to determine whether the samples of distillate, xylol waste, and commercial xylol showed significant differences among them. Unlike currently used analytical methodologies based on GC, the proposed methodology based on FTIR‐PCA‐ANOVA provided a simple way to monitor the samples (including xylol waste containing water traces and paraffin) throughout xylol recycling process. The results indicated there were no significant differences (p>0.05) between commercial and recycled xylol, being comparable. KBr pellets were prepared in order to obtain transmission FTIR spectra of liquid samples from xylol recycling process. Semi‐quantitative IR‐data were introduced in PCA analysis, and one‐way ANOVA test showed there were no significant differences between commercial and distilled xylol, which can be reused supporting waste prevention.