Method for authentication of animal species origin of leather products

A method for authentication of animal species origin of leather products, which includes the following steps:

• step 1, model establishment:
• (1) collecting leather samples from different animal species origins, set mass spectrometric parameters, cutting the grain surface of leather samples using a preheated electric soldering iron, instantly producing a stream of aerosols containing a large amount of complex ion mixtures, and detecting the resulting sample ions using the mass spectrometer;
• (2) importing the REIMS data into a LiveID software, creating a multivariate statistical model based on PCA-LDA analysis of the REIMS data, and evaluating the model with cross-validation tests;
• step 2, analysis of real leather samples:
• opening the LiveID software, selecting the established model, loading the same mass spectrometric parameters as in step 1, cutting the surface of real leather samples using the preheated electric soldering iron, producing real-time detection results for sample analysis;
• wherein the model of the electric soldering iron was CS-20 with a voltage of 220 V, a temperature of 380° C., and a full length of 170 mm;
• wherein the mass spectrometer was a QTOF high-resolution mass spectrometer equipped with a REIMS ambient ionization source;
• a scan time was 1 s;
• the mass spectra were acquired over the m/z 50-1200;
• a data acquisition could be carried out in either positive or negative ion mode;
• wherein the mass spectrometric parameters are as follows:
• cone voltage of 40 V, heater bias voltage of 60 V, cutting length of 1 cm, and auxiliary solvent flow rate of 0.15 mL/min.