RAMAN AND ATR-FTIR SPECTROSCOPY TOWARDS CLASSIFICATION OF WET BLUE BOVINE LEATHER USING RATIOMETRIC AND CHEMOMETRIC ANALYSIS  

作　　者：Megha Mehta Rafea Naffa Catherine Maidment Geoff Holmes Mark Waterland 

机构地区：[1]NZ Leather and Shoe Research Association(LASRA®),Palmerston North,New Zealand [2]School of Fundamental Sciences,Massey University,Palmerston North,New Zealand

出　　处：《Journal of Leather Science and Engineering》2020年第1期23-37,共15页皮革科学与工程（英文）

基　　金：funded by the Ministry of Business,Innovation and Employment(MBIE)grant number LSRX1801.

摘　　要：There is a substantial loss of value in bovine leather every year due to a leather quality defect known as“looseness”.Data show that 7%of domestic hide production is affected to some degree,with a loss of$35m in export returns.This investigation is devoted to gaining a better understanding of tight and loose wet blue leather based on vibrational spectroscopy observations of its structural variations caused by physical and chemical changes that also affect the tensile and tear strength.Several regions from the wet blue leather were selected for analysis.Samples of wet blue bovine leather were collected and studied in the sliced form using Raman spectroscopy(using 532 nm excitation laser)and Attenuated Total Reflectance-Fourier Transform InfraRed(ATR-FTIR)spectroscopy.The purpose of this study was to use ATR-FTIR and Raman spectra to classify distal axilla(DA)and official sampling position(OSP)leather samples and then employ univariate or multivariate analysis or both.For univariate analysis,the 1448 cm^(-1)(CH_(2) deformation)band and the 1669 cm^(-1)(Amide I)band were used for evaluating the lipid-to-protein ratio from OSP and DA Raman and IR spectra as indicators of leather quality.Curve-fitting by the sums-of-Gaussians method was used to calculate the peak area ratios of 1448 and 1669 cm^(-1 )band.The ratio values obtained for DA and OSP are 0.57±0.099,0.73±0.063 for Raman and 0.40±0.06 and 0.50±0.09 for ATR-FTIR.The results provide significant insight into how these regions can be classified.Further,to identify the spectral changes in the secondary structures of collagen,the Amide I region(1600-1700 cm^(-1))was investigated and curve-fitted-area ratios were calculated.The 1648:1681 cm^(-1)(non-reducing:reducing collagen types)band area ratios were used for Raman and 1632:1650 cm^(-1)(triple helix:α-like helix collagen)for IR.The ratios show a significant difference between the two classes.To support this qualitative analysis,logistic regression was performed on the univariate data to classify the samp

关 键 词：Raman spectroscopy Attenuated Total reflectance-Fourier transform InfraRed spectroscopy Principal component analysis Linear discriminant analysis Wet blue Distal axilla Official sampling position 

分 类 号：O65[理学—分析化学]