Multidimensional instrumental analysis of wet-blue leather hydrolysate

The U.S. leather industry generates more than 60,000 metric tons of chromium containing solid wastes every year, of which roughly half is attributed to chrome shavings. Much of these have been disposed in landfills. Owing to increasing environmental concern and a decrease in the number of disposal sites, extensive research has been done on the recovery of protein (collagen) and chromium from the shavings. The main objective of this work is to obtain a deeper insight into magnesium oxide (MgO) hydrolysis of chrome shavings and to look at newer ways of exploiting the products. Collagen hydrolysates are studied by various analytical techniques such as electrophoresis, chromatography and mass spectrometry. MgO hydrolysis produced fractions with molecular weight and charge heterogeneity as seen from sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), isoelectric focusing (lEF), capillary zone electrophoresis (CZE) and reverse phase-high performance chromatography (RP-HPLC). Consistent and complementary results are obtained from electrophoresis and chromatography. We created a multidimensional analytical mediodology to acquire a thorough, molecular-level characterization of these hydrolysates. The enhanced resolution space provided by these different techniques yields definitive and the most complete results, to date. The results obtained in this work provide useful information on the characteristics of the hydrolysates. This information will be helpful to develop better value-added applications for the chrome shavings. Such value-added products create a demand for the chrome shavings that will keep them out of the landfill.