Established methods and comparison of 10 organic acids based on reversed phase chromatography and hydrophilic interaction chromatography

High performance liquid chromatography (HPLC) methods have been established for simultaneously determining the 10 organic acids in fruit or soil. Two liquid chromatographic (LC) columns with reversed phase (RP) (Titank C18) and hydrophilic interaction (HILIC) (Poroshell 120 HILIC-Z) were selected to separate organic acids in molecular or ionic state, respectively. Meanwhile, the mobile phases had different solvents and pH values in the two states. Results indicated that these two columns can complement each other and avoid various matrix interferences. The limits of detection (LOD) of organic acids (S/N >= 3) were 0.002-0.521 mu g.mL(-1) in the molecular state and 0.003-0.459 mu g.mL(-1) in the ionic state, and the corresponding limits of quantification (LOQ) (S/N >= 10) were 0.007-1.737 mu g.mL(-1) and 0.009-1.530 mu g.mL(-1). The above methods can provide a technical support for the analysis of organic acid components in other matrices.