A determination method for clenbuterol residue in pork based on optimal particle size gold colloid using SERS

Authors: GUO, QINGHUI - China Agricultural University; PENG, YANKUN - China Agricultural University; Chao, Kuanglin - Kevin Chao; Qin, Jianwei - Tony Qin; CHEN, YAHUI - China Agricultural University; YIN, TIANZHEN - China Agricultural University

Submitted to: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/30/2023
Publication Date: 7/1/2023
Citation: Guo, Q., Peng, Y., Chao, K., Qin, J., Chen, Y., Yin, T. 2023. A determination method for clenbuterol residue in pork based on optimal particle size gold colloid using SERS. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. 302:1386-1425. https://doi.org/10.1016/j.saa.2023.123097.
DOI: https://doi.org/10.1016/j.saa.2023.123097

Interpretive Summary: Clenbuterol, a beta-agonist drug, is prohibited by the U.S. Food and Drug Administration (FDA) for human and veterinary use. Clenbuterol has reportedly been used illegally in several countries to enhance food animal production. Traditional chemical methods for detection of clenbuterol residues in meats (high-performance liquid chromatography-tandem mass spectrometry, gas chromatography mass spectrometry, liquid chromatography, enzyme-linked immunosorbent assay) require costly instruments, professional operators, and complex extraction processes. Therefore, an inexpensive, rapid, and simple method to detect clenbuterol residue in pork is needed. An ARS custom-designed point-scan Raman system was used to develop a method to detect the clenbuterol absorbed on gold nanoparticles and detected by their Raman spectral fingerprint. In this study, the particle growth method was used to prepare gold colloids of different sizes, and the enhanced effectiveness of gold colloids of different sizes. The most effective particle size was approximately 90 nm. A sample collection device was designed which effectively detects clenbuterol in meats with required accuracy, selectivity, and sensitivity. The detection limit of clenbuterol in pork by this method is 42 ng/g, which is sufficient for the pre-screening of pork in the market for clenbuterol. The same method can be expanded to detection of other regulated/banned substances used in food animal production. This benefits the food industry by providing a rapid, inexpensive methodology to protect the public from specific regulated substances not permitted in the human food supply.

Technical Abstract: Clenbuterol is often used as a feed additive to increase the percentage of lean meat in livestock. Meat containing clenbuterol can cause many illnesses and even death. In this paper, a particle growth method was used to prepare gold colloids of different sizes, and the effectiveness of gold colloids of different sizes on clenbuterol in pork was investigated. The results showed that the clenbuterol with the most effectiveness had a particle size of approximately 90 nm. Second, a sample collection component was redesigned to detect clenbuterol, solving the problem of poor reproducibility of Surface-enhanced Raman scattering (SERS) detection caused by inconsistency and variability in droplet size and shape. The volume of samples and concentrations of aggregating compounds was optimized. The 5 µL of enhanced substrate, 7.5 µL of clenbuterol, and 3 µL of 1 mol/L of NaCl solution had the best performance. Unary linear regression models were established between the concentration of clenbuterol residue in the pork and the Raman intensity at 390, 648, 1259, 1472, and 1601 cm-1. The results showed that the unary linear regression models at 390, 648, and 1259 cm-1 had lower root mean square errors than those at 1472 and 1601 cm-1. The intensity of the best three bands and the concentration of clenbuterol residue in the pork were selected to establish a multiple linear regression model from which the concentration of clenbuterol residue in the pork was predicted. The results showed that the determination coefficients (R2) of the calibration set and the prediction set were 0.99 and 0.99, respectively. The root mean square errors (RMSE) of the calibration set and the prediction set were 0.169 and 0.184, respectively. The detection limit of clenbuterol in pork by this method is 42 ng/g, which is sufficient for the crude screening of pork in the market for clenbuterol.