Abstract: A method for the simultaneous determination of 8 illegal drugs in internet-famous health foods was established by thin-layer chromatography (TLC) coupled to ultra performance liquid chromatography-tandem mass spectrometry (TLC-UPLC-MS/MS). The sample pretreatment was accomplished by TLC, and subsequently the chromatographic separation was done on a Kinetex 100 RP-18 (100 mm × 2.1 mm, 1.6 μm) column with gradient elution using a mobile phase consisting of 1 mmol/L ammonium acetate solution (with 0.1% acetic acid) and acetonitrile. The multiple reaction monitoring (MRM) mode was used to quantify 8 illegal drugs, sibutramine, lovastatin, simvastatin, ephedrine, caffeine, phenolphthalein, phenformin and sildenafil. The results showed that good linear relationships in the range of 0.5–100 μg/L were observed for all of the analytes with correlation coefficients no less than 0.995 8. The limits of detection (LODs) and limits of quantification (LOQs) ranged from 0.09 to 0.29 μg/kg and from 0.31 to 0.79 μg/kg, respectively. The average recoveries for various samples were in the range of 67.3%–101.1%, and the relative standard deviations for six replicate determinations were no more than 16.5%. Totally, 23 out of 45 samples were identified to contain the illegal drugs. The established method can be suitable for rapid screening and quantification of these 8 illegal drugs in internet-famous health foods.

Key words: thin-layer chromatography, ultra performance liquid chromatography-tandem mass spectrometry, internetfamous health foods, illicit drugs