A simple procedure based on stir bar sorptive extraction (SBSE) and high-performance liquid chromatography-fluorescence detection (HPLC-FLD) is presented for the determination of 15 polycyclic aromatic hydrocarbons (PAHs) in herbal tea prepared with Mate leaves (Ilex paraguariensis St. Hil.). The influence of methanol and salt addition to the samples, the extraction time, the desorption time and the number of desorption steps, as well as the matrix effect, were investigated. Once the SBSE method was optimised (10 mL of Mate tea, 2h extraction at room temperature followed by 15 min desorption in 160 microL of an acetonitrile (ACN)-water mixture), analytical parameters such as repeatability (< or = 10.1%), linearity (r2 > or = 0.996), limit of detection (LOD, 0.1-8.9 ng L(-1) ), limit of quantitation (LOQ, 0.3-29.7 ng L(-1) and absolute recovery (24.2-87.0%) were determined. For calibration purposes, a reference sample was firstly obtained by removing the analytes originally present in the lowest contaminated Mate tea studied (via SBSE procedure) and then spiked at 1-1200 ng L(-1)range. The proposed methodology proved to be very convenient and effective, and was successfully applied to the analysis of 11 Mate tea samples commercialised in Brazil. The results of the commercial Mate tea samples found by the SBSE approach were compared with those obtained by liquid-liquid extraction (LLE), showing good agreement.
"microextraction (SPME)      and stir bar sorptive extraction (SBSE) , have been successfully applied for PAH quantification. Headspace sorptive extraction (HSSE) is an SBSE-derived microextraction technique  , in which the polydimethylsiloxane (PDMS) coated stir bar is exposed to the headspace sample vial, trapping the analytes into its extracting phase coating. "
[Show abstract][Hide abstract] ABSTRACT: A solvent-free method is described for the determination of 10 volatile polycyclic aromatic hydrocarbons (PAHs), considered as priority pollutants by the EU, in different herbal infusions using headspace sorptive extraction (HSSE) and gas chromatography-mass spectrometry (GC-MS). The parameters affecting both the extraction and thermal desorption steps in the HSSE were optimized by means of Plackett-Burman designs. Ten millilitres of the herbal infusion was submitted to the HSSE preconcentration in the presence of salt for 4h at 88°C. The use of d(10)-phenanthrene as internal standard not only improved the repeatability of the method but allowed quantification of the samples against external aqueous standards. Detection limits ranged between 11 and 26ngL(-1).
Journal of Chromatography A 06/2014; 1356. DOI:10.1016/j.chroma.2014.06.060 · 4.17 Impact Factor
"There are some studies performed about " yerba mate " . Camargo and Toledo (2002), Kamangar et al. (2008) and Zuin et al. (2005) analysed samples of different Brazilian brands. Vieira et al. (2010) evaluated samples obtained from three Brazilian suppliers that were collected at three stages of processing and Ziegenhals et al. (2008) studied samples purchased from different manufactures with unknown origin. "
[Show abstract][Hide abstract] ABSTRACT: Polycyclic aromatic hydrocarbons (PAHs) occurrence in 50 samples marketed in the main supermarkets from Argentina was surveyed. A high performance liquid chromatography (HPLC) method was applied with fluorescence detection (FLD) and UV-VIS diodes array detector (DAD) for the analysis of 16 PAHs in "yerba mate" (Ilex paraguariensis), with recoveries higher than 89% and limits of detection and quantification lower than that found by other methodologies in previous studies. Contamination expressed as the sum of 16 analysed PAHs ranged between 224.6 and 4449.5 μg kg(-1) on dry mass. The contamination expressed as PAH4 (sum of benzo(a)pyrene, chrysene, benzo(a)anthracene and benzo(b)fluoranthene) varied between 8.3 and 512.4 μg kg(-1). The correlation coefficient for PAH2 (sum of benzo(a)pyrene and chrysene) and PAH4 groups was 0.99, for PAH2 and PAH8 (sum of benzo(a)pyrene, chrysene, benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(g,h,i)perylene, dibenzo(a,h)anthracene and indeno(1,2,3cd) pyrene) 0.97 and for PAH4 and PAH8 0.98.
Food Additives and Contaminants: Part B Surveillance 05/2014; 7(4):1-7. DOI:10.1080/19393210.2014.919963 · 0.88 Impact Factor
"As yet, conventional procedures of sample preparation for PAHs determination in teas have included extraction using various solvents (acetone, ethyl acetate, dichloromethane, hexane) and clean-up step, usually with the use of solid-phase extraction (SPE) or gel permeation chromatography (Lin et al. 2005; Singh et al. 2011). Apart from these approaches, accelerated solvent extraction and stir bar sorptive extraction were successfully applied to PAH analysis (Ziegenhals et al. 2008; Zuin et al. 2005). The purified extract is then analysed by gas chromatography or liquid chromatography in combination with different types of detectors. "
[Show abstract][Hide abstract] ABSTRACT: The aim of this work was the evaluation of QuEChERS extraction method for polycyclic aromatic hydrocarbon (PAH) determination in various types of tea. In the experiment, different kinds of extraction solvents, sorbents and a final method of sample preparation were compared. The final extracts were analysed by gas chromatography-selected ion monitoring-mass spectrometry. The results suggest that acetonitrile extraction, clean up with SAX and final liquid-liquid extraction was the best combination giving the most purified extracts and acceptable compound recoveries for different types of teas. In the study of real samples, compounds belonging to light PAHs were mostly detected, and heavy polycyclic aromatic hydrocarbons, including benzo[a]pyrene, were not identified in any of samples.
Environmental Science and Pollution Research 07/2013; 21(2). DOI:10.1007/s11356-013-2022-1 · 2.83 Impact Factor
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