ABSTRACT
OBJECTIVE: To develop a fast detecting method for three dyes (auramine O, amaranth and sunset yellow) illegally added into Chinese herbal medicine by ion mobility spectrometry (IMS). METHODS: The analysis was performed on ion mobility spectrometry, with source voltage 1 800 V for negative source and 2 300 V for positive source, drift tube voltage 7 500 V, gas inlet temperature 180℃, drift tube temperature 180℃, gate voltage 45 V, gate pulse width 120 μs, drift gas flow 1.2 L·min-1, exhaust pump 0.8 L·min-1, run time 30 s and spectrum length 25 ms. The samples were extracted by methanol, and then injected into the IMS system. The judgement of whether dye was added or not was made by comparing the migration time of the test samples with that of the reference substances. RESULTS: The auramine O, amaranth and sunset yellow could be rapidly identified. The minimum detection concentration of each compound was determined according to the signal to noise ratio (S/N) of 3. CONCLUSION: The IMS method for detecting auramine O, amaranth and sunset yellow illegally added into Chinese herbal medicine is simple, rapid and expected to be used as an initial screening method in drug rapid detecting system.