Simultaneous determination of fats used by the leather tanning industry: Monitoring of fatliquoring baths

The simultaneous spectrophotometric determination of fats in mixtures used by the leather tanning industry by use of a rigid multivariate calibration method is reported. Mixtures of analytes with overlapped UV-vis spectra were quantified with relative standard errors of prediction (RSEP) less than 3%, that increase, in the presence of high co-linearity. Fat and dye mixtures can be resolved with RSEP values below 4%. The ensuing method was used to monitor fatliquoring and fatliquoring/dyeing baths as a means for the expeditious control of exhaustion in the leather fatliquoring bath. The method's simplicity makes it amenable to automatic implementation even in quite simple flow manifolds.