A novel method for the quality control of saffron through the simultaneous analysis of authenticity and adulteration markers by liquid chromatography-(quadrupole-time of flight)-mass spectrometry

- A LC-MS methodology was developed for the quality control of saffron.
- Glycosylated kaempferol derivatives were determined as authenticity markers.
- Detection of geniposide revealed saffron adulteration with gardenia.
- LC-MS method enabled the detection of up to 0.2% of adulteration.

A liquid chromatography-(quadrupole-time of flight)-mass spectrometry methodology was developed to assess the authenticity of saffron through the analysis of a group of kaempferol derivatives recently proposed as novel authenticity markers as a result of a metabolomic study of saffron (kaempferol 3-O-glucoside, kaempferol 3-O-sophoroside, kaempferol 3,7-O-diglucoside, kaempferol 3,7,4′-O-triglucoside, kaempferol 3-O-sophoroside-7-O-glucoside). Geniposide was also studied as an adulteration marker of saffron with gardenia. The optimized chromatographic conditions enabling the simultaneous separation of glycosylated kaempferols and geniposide consisted of the use of a C18 column and an elution gradient with acetonitrile and water as mobile phases (both with formic acid at 0.1%). A strategy was proposed to evaluate the minimum quantifiable adulteration percentage which was established at a 0.2% regardless of the adulterant employed. The analysis of nineteen commercial samples showed the method to be specific and suitable for saffron quality control.