J. Sep. Sci. 2013, 00, 1–6 1 Peter Quinto Tranchida 1 Mariosimone Zoccali 1 Flavio Antonio Franchina 1 Ivana Bonaccorsi 1 Paola Dugo 1,2 Luigi Mondello 1,2 1 Dipartimento Farmaco-Chimico, Facolt ` a di Farmacia, Universit ` a degli Studi di Messina, Messina, Italy 2 Centro Integrato di Ricerca (C.I.R.), Universit ` a Campus-Biomedico, Roma, Italy Received August 3, 2012 Revised October 23, 2012 Accepted October 25, 2012 Short Communication Fast gas chromatography combined with a high-speed triple quadrupole mass spectrometer for the analysis of unknown and target citrus essential oil volatiles The present research description is focused on the evaluation of a high-speed triple quadrupole mass spectrometer, carried out under moderately fast gas chromatography conditions (analysis time: 17 min). The mass spectrometric system is capable of operation under high-speed GC conditions, in both full-scan (maximum scan speed: 20 000 amu/s) and multiple reaction monitoring modalities. Furthermore, the triple quadrupole system can generate full scan and multiple reaction monitoring data simultaneously, also in a very rapid manner. A fast method was developed for the: (i) qualitative analysis of untargeted Citrus essential oil compounds, and (ii) the quali/quantitative analysis of targeted ones, namely three preservatives (o-phenylphenol, butylated hydroxytoluene, butylated hydroxy- anisole). The mass spectrometric system generated a more-than-sufficient number of data points/peak for both identification and quantification purposes. The level of sensitivity, reached through the multiple-reaction-monitoring side of the analysis, widely exceeded the requirements of current legislation. Method validation, related to the targeted analysis, was performed considering precision of retention times, peak areas and ion ratios; limits of detection/quantification, and accuracy were also measured. Keywords: Citrus essential oil / Fast gas chromatography / Food analysis / Triple quadrupole mass spectrometry DOI 10.1002/jssc.201200742 1 Introduction In general, triple-quadrupole mass spectrometry (QqQ MS) is employed for the sensitive and selective analysis of tar- get analytes (i.e. polyaromatic hydrocarbons, pesticides, etc.), usually in the multiple reaction monitoring (MRM) mode. MRM GC-QqQ MS methods usually require a great deal of optimization because it is necessary to define, for each target analyte, time window, precursor, and product ions, along with the most appropriate collision cell energy. The total number of product ions is generally two, one exploited for quantifica- tion and the other for qualification purposes. Signal-to-noise ratios undergo a great increase in GC-MSMS applications be- cause of the considerable reduction of chemical background noise. Correspondence: Prof. L. Mondello, Dipartimento Farmaco- chimico, Facolt ` a di Farmacia, Universit ` a degli Studi di Messina, viale Annunziata, 98168 Messina, Italy E-mail: lmondello@unime.it Fax: +39-090-358220 Abbreviations: BHA, butylated hydroxyanisole; BHT, buty- lated hydroxytoluene; IS, internal standard; LoD, limits of de- tection; LoQ, limits of quantification; MRM, multiple reaction monitoring; MRL, maximum residue limit; OPP, o-phenyl- phenol; QqQ MS, triple-quadrupole mass spectrometry In a recent work, focused on the development of a low- pressure, fast GC-QqQ MS method, 150 pesticides (two tran- sitions each) were subjected to quali/quantitative determina- tion [1]. A low-resolution 10 m × 0.53 mm ID × 1 m d f column was employed, highlighting the enhanced selectivity and targeted nature of tandem MS. Overall, 60 transitions were performed in each time segment, with a 2.5 ms dwell and a 1 ms interdwell delay times. Such operational condi- tions led to a cycle time of 210 ms (4.8 Hz), sufficient for quantification purposes. The work reported was purely a tar- geted one, with less emphasis devoted to the chromatography step, compared to the MS-based one. It is generally accepted that a high-resolution, fully optimized chromatography sepa- ration, is not necessary prior to a tandem MS analysis. Several “target” GC-MSMS experiments have been reported in the lit- erature, many of which of recent appearance [2–7]. The objective of this fast GC-MSMS investigation is fo- cused on the evaluation of a “fast” tandem MS instrument. The present research differs from previous investigations be- cause the QqQ MS system is characterized by the possibility to operate under alternating full scan and MRM conditions, in the same analysis and in a high-speed manner. It must be added, however, that the investigation herein described is not a comparative one. The samples subjected to an untargeted qualitative analysis consisted of Citrus essential oils; with regards to targeted quantitative analysis, attention was de- voted to three preservatives [o-phenylphenol (OPP), butylated C  2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim www.jss-journal.com