Quantitative analysis of ethylene precursor ACC in plant samples by liquid chromatography-tandem mass spectrometry

Ethylene (C₂H₄) is a gaseous phytohormone that regulates various plant physiological processes and mediates the responses of the plants to various environmental stresses. 1-Aminocyclopropane-1-carboxylic acid (ACC) is the direct precursor of the phytohormone ethylene, and is also considered as a plant growth regulator. Accurate quantification of ACC is critically important in investigating its function. However, it remains challenging to accurately quantify ACC in plant tissues because it is a small, electroneutral molecule with very low concentrations.

An easy, cost-saving, and highly efficient quantitative method for ACC in plant tissues was set up by liquid-liquid micro-extraction (LLME) purification with green solvent ethyl-acetate, and the precise control of the mobile phase entering into the mass spectrometer combined with the ultra-high performance liquid chromatography electrospray ionization-triple quadrupole mass spectrometer (UHPLC-ESI-MS/MS).

The contents of ACC in 10 mg of different fresh fruits were detected. The established method had limit of detection (LOD) (2.5 pg), matrix effect (ME) (92.6%), good precision (3.54%), recovery rate (95.82%), and a good linear relationship within the range of 0.5 to 1500 ng.mL^-1 (R² = 0.9998).

We have developed an easy, sensitive, and cost-saving quantitative method for ACC in plant tissues without derivatization which is useful for the precise quantification of ACC in plant tissues.