Abstract:
Leather processing employs a series of heavy chemicals that are
detrimental to human health and environment at different stages of
tanning. Determination of the elemental concentrations becomes
complex especially using the conventional techniques since they
involve tracking individual elements at different stages of leathermaking
processes. The study investigated the effect of crusting operations
on the elemental concentrations using energy dispersive X-ray
fluorescence (EDXRF) and principal component analysis (PCA). The
spectral measurements of the post-tanned samples were carried out
in vacuum using EDXRF-Rigaku NEX CG. The concentrations of elements
were determined by advanced FP (fundamental Parameter)
software-RPF-SQX (Rigaku Profile Fitting-Spectra Quant X) software.
The abundance of the elements in the leather crusts was in the order
Cr>S>Na>Cl>Al>Si>Ca>V>K>P>Zr>Zn>Fe>Mn>As>Ti>Cu>Pb>Ni>Ga
> Br > Hg. The concentration levels for the majority of the elements
in the crusts were higher than the recommended safe extractible
levels for leather. Combination of EDXRF and principal component
analysis in this study has shown potential in the leather industry to
monitor the chemical concentrations. A combination of Cu and RX9
secondary targets exhibited sufficient and excellent excitation efficiency
for detection of the majority of elements in leather crusts. The
valuable tracers for classification in the crusting operations are Cr, S,
Cl, P, V, K, Mn and Zn. Retanning process increases S and Cu whereas
levels of Cl decrease in the crusts. Dyeing and Fatliquoring processes
raise the concentration levels of S while decreasing the Cl level.
