Analysis of seven purines and pyrimidines in pork meat products by ultra high performance liquid chromatography-tandem mass spectrometry.

An ultra high performance liquid chromatography-tandem mass spectrometry method (UPLC-MS/MS) is proposed for the simultaneous quantification of inosine, adenosine, guanosine, uridine, hypoxanthine, xanthine and uric acid in pork meat, dry-cured and cooked ham. Samples were added with (15)N(2)-xanthine (internal standard) and extracted with boiling water for 30 min. Supernatants were washed with hexane, added with formic acid 10% in water, methanol:acetone (1:1, v/v), evaporated to dryness under N(2), and finally re-dissolved in water prior to injection. Chromatographic separation was carried out with a HSS T3 column with a total time of analysis of 15 min. Two specific transitions for each compound were used for identification and quantification (with matrix matched calibration curves). Linearity, limit of detection, repeatability and accuracy were evaluated. The method was used to quantify the seven purines and pyrimidines in 15 commercial samples.