Determination of ten organic acids in fresh litchi based on high performance liquid chromatography with triple quadrupole mass spectrometry technique

In order to determine the amount of organic acids in litchi and their effects on the flavor of litchi, an effective method was developed for the determination of ten organic aicds (including malic acid, citric acid and other organic aicds) in fresh litchi by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Poroshell chromatographic column was used as the separation column. Formic acid water and acetonitrile was used as the mobile phase. The electrospray ion source and negative ion muptiple reaction monitoring mode were also used. The analytes were quantified by the external standard method, and the pretreatment and mass spectrometry conditions were evaluated. Ten organic acids showed good linearities in the range of 0.1-10 mg/L, and the correlation coefficients (r) were all above 0.99. The limits of detection (LODs) were 0.1-0.8 μg/kg, and the limits of quantification (LOQs) were 0.2-2.5 μg/kg. The average recoveries of ten organic acids in fresh litchi samples were 91%-99% with the relative standard deviations of 1.9%-7.9%. This method is rapid, easy and sensitive. Therefore, it is suitable for the quick determination and analysis of ten organic acids in fresh litchi, and it can also provide reference for the determination of organic acids in other fruits.