VALIDATION OF TRACE AMOUNT DETERMINATION OF MONOCYCLIC AND POLYCYCLIC AROMATIC HYDROCARBONS IN SEVERAL FRUITS


A. Paris, J. Ledauphin, J-L. Gaillard
Organization(s): Normandie Université, UNICAEN, Unité de Recherche Aliments Bioprocédés Toxicologie Environnement (UR ABTE EA 4651), 14000 Caen, France

 

Monocyclic aromatic hydrocarbons (BTEX) and polycyclic aromatic hydrocarbons (PAHs) are volatile organic compounds that can originate from the incomplete combustion of wood, coal, or fuel. These aromatic hydrocarbons are present in all environmental compartments (air, water, and soil) and are considered as priority pollutants.

Due to the difference of volatility between BTEX and PAHs, two complementary analytical approaches were tested to quantify these compounds at the ppb level in apples, pears, plums and grapes. Headspace Solid Phase Microextraction (HS-SPME) with a carboxen/polydimethylsiloxane fiber was used to recover BTEX and light PAHs (MW≤178 g/mol). Heaviest PAHs were extracted using Ultra Sound (UAE) followed by Solid Phase Extraction (SPE) with Envi Chrom-P cartridges. Separations and detections were performed using a Gas Chromatograph (DB5-MS column, 60m x 0.25mm i.d x 0.25µm) coupled to a quadrupole Mass Spectrometer (GC-MS) acquiring in SIM mode.

Calibration was performed in the range from 0 to 10 ng/g for 20 aromatic compounds in the different fruits. For both extraction techniques, linearity of calibrations was verified by the calculation of coefficient of determination (R²) which values are between 0.95 and 0.99 for HS-SPME and between 0.92 and 0.99 for UAE followed by SPE.

Calibration slopes obtained for the different fruits were compared. Slopes values are similar since relative standard deviations (RSD) reach until 9 % for ethylbenzene and 4 % for acenaphthene. Thus, HS-SPME is a suitable methodology for investigation of BTEX and light PAHs. Procedure consisting of UAE followed by SPE provides accurate determination of the content of heavier PAHs, including notably indeno[1,2,3,c,d]pyrene and benzo[a]pyrene (indicator of PAHs occurrence) with respective RSD of 4 and 7%.

Both procedures allow efficient extractions and reliable estimations of PAHs and BTEX at ppb level in complex foodstuffs matrices such as fruits.

 

Alice Paris

Education

Currently doctoral student in biology, environment, and food chemistry since 2013, my school curriculum is built around biology and chemistry applied to health. I have a Master degree in biotechnology and health: engineering and therapeutic strategies (University of Reims Champagne Ardennes, 2011), a Bachelor degree in biology, health and animal physiology (University of Caen-Normandy, 2010), a Three-year university degree in science of life, earth, environment, and health engineering (University of Rouen, 2009), and a Two-year university degree in technology chemistry and bioprocess engineering (University of Caen-Normandy, 2008)

Research activities

My doctoral project in the research unit (EA 4651) : Aliments Bioprocédés Toxicologie Environnements (IUT Caen) study the impact of air pollutants on food quality with application to fruit crops. This work provide me a high scientific qualifications in extraction techniques (Ultrasound Assisted Extraction: UAE, Solid Phase Extraction: SPE, and Headspace Solid Phase Micro-extraction: HS-SPME) and in identification and quantification of aromatic hydrocarbons through gas chromatography coupled to mass spectrometry

My several training experiences provided me skills in:

Immunoturbidimetric analysis (microalbumin, CRP) and metrology (reagent stability, repeatability, reproducibility, correlation, interference) during the technical validation of medical devices for in vitro diagnostic for the BIOLABO company (Maizy)

Microbiology (bacterial strains cultures in presence of carbon as substrates with or without nitrogen deficiency) and analytical biochemistry (identification and quantification of polyhydroxyalkanoates monomers by IRTF spectroscopy and gas chromatography: GC-FID) during the study on the influence of the carbon substrate on bacterial synthesis of polyhydroxyalkanoates in the research unit (EA 3914) Physico-Chimie et Biotechnologies (IUT Caen)

Biochemistry (monitoring of enzymatic hydrolysis of protein) during the monitoring of a tryptic digestion by capillary zone electrophoresis in the Laboratoire d’Analyse des Systèmes Organiques Complexes (Évreux)