Rapid Determination of Tetracyclines Hydrochloride Using ATR FT-MIR Spectroscopy

Antibiotic residues in animal-derived foods have brought serious threats to human health as well as economic losses to the food industry. Given that analytical methods are crucial but remain limited, a rapid, reliable, and cost-effective method is needed for detecting antibiotic residues. In this paper, a method using attenuated total reflection Fourier transform mid-infrared (ATR FT-MIR) spectroscopy combined with chemometrics was established for the detection of tetracyclines hydrochloride (TCsH). Firstly, TCsH powders were scanned using ATR FT-MIR spectroscopy, and the characteristic peaks of these samples were found in this region. Then, milk samples with different TCsH concentrations (1 to 160 ppb) were measured and were analyzed using principal component analysis (PCA) and partial least squares regression (PLSR) algorithms. The results showed that the kinds of TCsH in milk could not be classified. However, TCsH concentration ranging from 1 to 160 ppb in milk samples was successfully determined with high determination coefficient (R ²) values of 0.88–0.90, low root-mean-square errors values of 9.76–18.2, and high residual predictive deviation (RPD) values close to or greater than 3. These results indicated that ATR FT-MIR spectroscopy could be used to identify TCsH powders based on their unique spectral features, and was suitable for the rapid detection of TCsH concentration in milk.