Objective: To establish a method for the determination of anisodamine, atropine, and scopolamine in infant complementary foods and formula milk powder by solid-phase extraction combined with liquid chromatography-tandem mass spectrometry. Methods: Commercially available infant complementary foods (biscuits, noodles, and rice flour) and formula milk powder were collected. The samples were homogenized, extracted ultrasonically with 0.5% formic acid-80% aqueous methanol solution, and purified using polymer-based mixed-mode cation-exchange solid-phase extraction cartridges. Gradient elution was performed with 0.02% formic acid-1 mmol/L ammonium formate aqueous solution and methanol as mobile phases. The target compounds were separated using an XBridgeTM BEH C18 column (150 mm×3 mm, 2.5 μm), detected by positive electrospray ionization multiple reaction monitoring mode, and quantified using the isotope internal standard method. Results: When 0.5% formic acid-80% aqueous methanol solution was used for extraction and the loading volume was 5 mL, the peak areas and average spiked recovery rates of the target compounds were relatively high. The matrix effects of infant food were evaluated using the optimized method. Noodles showed a matrix suppression effect, whereas biscuits, rice flour, and formula milk powder exhibited matrix effects close to 100%, which were corrected by isotope internal standard quantification. The three tropane alkaloids had good linear relationships in the range of 0.1-50 ng/mL, with all correlation coefficients greater than 0.999. The limits of detection and limit of quantification were 0.1 and 0.3 μg/kg, respectively. At spiked concentrations of 0.3, 8.0, and 40.0 μg/kg, the average spiked recovery rates of anisodamine, atropine, and scopolamine were 95.7%-102.6%, 93.2%-104.7%, and 95.5%-104.1%, respectively, with relative standard deviations of 1.4%-8.5%, 1.5%-8.4%, and 3.1%-8.5%, respectively. None of the three tropane alkaloids were detected in 100 infant complementary food samples. Among 60 infant formula milk powder samples, atropine and scopolamine were detected in one sample, while anisodamine was not detected. Conclusions The method is simple, accurate, and sensitive, and can effectively eliminate the interference of complex matrix effects. It can be applied to the quantitative determination of tropane alkaloids in infant foods.
liquid chromatography-tandem mass spectrometry ; solid-phase extraction ; anisodamine ; atropine ; scopolamine ; infant complementary food ; formula milk powder