RESUMEN
A method of non-target pigment screening in Chinese softshell turtle has been established by using liquid chromatography coupled to time of flight mass spectrometry (LC-Q-TOF MS). After being purified by a simple acetonitrile extraction work, the non-target pigment in 20 Chinese softshell turtle samples was detected by liquid chromatography-photodiode array detection (LC-DAD). The S7 sample, which has a strong spectral response, was chosen to extract the mass spectrometry information of the non-target pigment on different gradient elution conditions. In order to get the characteristic molecular mass ion (564.397 73 Da and 564.395 61 Da) of the non-target pigment, qualitative spectral full scan with negative sample was used. The molecular formula generation data and the literature information prompted speculation that the non-target pigment was canthaxanthin with the formula of C40H52O2. By comparing the canthaxanthin standard material MS/MS information, the result was confirmed accurate. A strategy of LC-Q-TOF MS method for the qualitative analysis of unknown compounds is discussed, and the results indicated that the described method can be effectively applied to qualitative analysis for non-target pigment in Chinese softshell turtle.
