Rapid Determination of Phenylalanine by Micro-chip Based Field Asymmetric Waveform Ion Mobility Spectrometry Technology

The microchip field asymmetric ion mobility spectrometry (FAIMS) technology was used for rapid analysis of phenylalanine (PHE) using the metal diffusion tube-microchip μ-FAIMS system. The test pressure was set at 0.25 MPa, and the temperature of the gas generator for the diffusion tube was at 190 °C. The ion characteristic spectra were acquired under the optimized conditions with a gas flow rate of 2000 mL min −1 , a dispersion voltage of 152.8 V and a compensation voltage of −0.62 V for phenylalanine in positive mode. Phenylalanine gas samples with different concentrations were analyzed in detail by FAIMS. The results showed that the ion intensity was linearly correlated with phenylalanine concentration in the range from 6 mg L −1 to 20 mg L −1 , with the detection limit of 5.93 mg L −1 for phenylalanine. This investigation shows the feasibility of FAIMS technique for rapid detection of phenylalanine. The FAIMS instrument is simple, and has high sensitivity and fast response, and shows great potential for rapid detection of phenylalanine.