Quantification of 2-acetyl-1-pyrroline in rice by stable isotope dilution assay through headspace solid-phase microextraction coupled to gas chromatography-tandem mass spectrometry

A new and convenient synthesis of 2-acetyl-1-pyrroline (2AP), a potent flavor compound in rice, and its ring-deuterated analog, 2-acetyl-1-d2-pyrroline (2AP-d2), was reported. A stable isotope dilution assay (SIDA), involving headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-positive chemical ionization-ion trap-tandem mass spectrometry (GC-PCI-IT-MS-MS), was developed for 2AP quantification. A divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber was used for HS-SPME procedure and parameters affecting analytes recovery, such as extraction time and temperature, pH and salt, were studied. The repeatability of the method (n=10) expressed as relative standard deviation (RSD) was 11.6%. A good linearity was observed from 5.9 to 779ng of 2AP (r2=0.9989). Limits of detection (LOD) and quantification (LOQ) for 2AP were 0.1 and 0.4ngg-1 of rice, respectively. The recovery of spiked 2AP from rice matrix was almost complete. The developed method was applied to the quantification of 2AP in aerial parts and grains of scented and non-scented rice cultivars. © 2010 Elsevier B.V.This research was funded by the Office National Interprofessionnel des Grandes Cultures (ONIGC) as a part of the “Plan de Relance de la Filiere Riz Camarguaise” project. We thank the Centre Français du Riz (CFR, Arles, France) for providing the rice samples. We also thank Languedoc Roussillon region and Cirad for supporting the doctoral fellowship of the author I. Maraval

Towards graphyne molecular electronics

Photograph of competitors in the 1997 National Cutting Horse Association Summer Cutting Spectacular held at Will Rogers Coliseum in Fort Worth, Texas