Rapid determination of ferulic acid in three kinds of Chinese herbs by direct analysis in real-time mass spectrometry

A new method of direct analysis in real-time integrated with mass spectrometry was established and applied to the rapid determination of ferulic acid in Chinese herbs. Instrument parameter settings were optimized to obtain the sensitive and accurate determination of ferulic acid. At the sample introduction speed of 0.5 mm/s, high signal intensity of [M-H] − ( m/z 193) for ferulic acid was achieved in the negative ion mode by utilization of high purity helium gas at 350°C. The calibration curve was linear over the range of 5 – 100 mg/L with the correlation coefficient r = 0.9846 and relative standard deviation (n = 6) in the range of 2.0 to 6.1%. The limit of detection ( S/N = 3) and limit of quantitation ( S/N = 10) were 0.4 and 1.2 mg/L respectively. The recoveries were in the range of 90.6–114.2%. The results of direct analysis in real time-mass spectrometry were in agreement with those obtained by high performance liquid chromatography. The proposed direct analysis in real time mass spectrometry method is a simple, rapid and high-throughput approach for the determination of ferulic acid in Chinese herbs.