A rapid method for the determination of levoglucosan in NIST standard reference material 1649a by HPLC-MS/MS

The biomass burning marker levoglucosan is produced via combustion of woody cellulose at temperature over 300 °C, and is hence widely used to trace fires or discriminate urban air pollution sources. In this context, it is very useful the availability of a standard reference material (SRM) with a certified value of levoglucosan, to check the quality, reliability and accuracy of the measurements. To this aim, in this work a simple and rapid method was developed for the detection and quantification of levoglucosan in an urban dust Standard Reference Material 1649a, available from the National Institute of Standards and Technology and the results were compared to those obtained in our previous investigations. 5 mg of SRM particulate material were analyzed, after an ultrasonic extraction with deionized water, using a column, with stationary phase based on hydrophilic interaction, assembled on a liquid chromatography system combined with triple tandem quadrupole mass spectrometry (HPLC-MS/MS) with electrospray ionization. Unlike existing methods, it does not require neither derivatization or extensive clean-up of the sample. For the method validation, the matrix effect, limit of detection (LOD), limit of quantification (LOQ), linearity, accuracy, recovery and precision were evaluated. The concentration determined in the SRM was in good agreement with that determined by gas chromatography-mass spectrometry in our previous study. The precision, tested on SRM, over five replicates and five aliquots were within 15%, whereas accuracy ranged between 85 and 115%. To demonstrate the method is fit for the purpose, particulate matter samples collected in an urban area of the city of Rome Italy were analyzed. The amount of levoglucosan was consistent with the urban emissions typical of the considered season.