Fig. 1. Chemical structural formula of zilpaterol

Fig. 2. Zipatero’s theoretical calculation results
(a): Optimize molecular structural formula of Raman zilpaterol hydrochloride; (b): Comparison between theoretical spectra and solid Raman spectra

Fig. 3. SERS peak intensity at 1 116 cm^-1 under different detection conditions
(a): Optimization of gold sol volume ratio; (b): Optimization of mixing time

Fig. 4. SERS spectra of different concentrations of zilpaterol in aqueous solutions
a—h are solid, water, 1, 5, 10, 25, 50, 100 mg·L^-1 solutions

Fig. 5. Linear relationship between peak intensity and concentration

Fig. 6. Comparison of different extraction solvents
a—g are solid, A mixture of acetonitrile and isopropanol (4∶1) extracts the blank matrix, a mixture of acetonitrile and isopropanol (4∶1) adds standard extraction, acetonitrile n-hexane extracts the blank matrix, acetonitrile n-hexane spikes extraction, ethyl acetate extraction Blank matrix, ethyl acetate spiked extraction

Table 1. Recovery rate and precision determination results(n=3)