Polycyclic aromatic hydrocarbons in teas using QuEChERS and HPLC-FLD.

Polycyclic aromatic hydrocarbons (PAHs) are food-processing contaminants considered to be carcinogenic and genotoxic. Due to its drying process stage, teas may be contaminated with PAHs. The aim of the study was to validate an analytical method involving QuEChERS and HPLC-FLD for the determination of PAH4 in teas and evaluate the contamination levels in 10 different types of teas from Brazil. Recoveries varied from 54% to 99% and relative standard deviations from 1% to 21%. Limits of detection and quantification were from 0.03 to 0.3 µg/kg and 0.1 to 0.5 µg/kg, respectively. Mate tea presented the highest PAH levels, with PAH4 varying from 194 to 1795 µg/kg; followed by black (1.8-186 µg/kg), white (24-119 µg/kg), and green teas (3.1-92 µg/kg). Teas with lowest PAH4 were strawberry, lemongrass, peppermint, and boldo. Only trace levels of PAHs were detected in tea infusions, so apparently it would not affect PAH intake by Brazilian population.

Optimisation of extraction methods and quantification of benzo[a]pyrene and benz[a]anthracene in yerba maté tea by isotope dilution mass spectrometry.

A gas chromatography-isotope dilution mass spectrometry (GC-IDMS) technique was developed for the quantification of two heavy polyaromatic hydrocarbons (PAHs), benz[a]anthracene and benzo[a]pyrene, in yerba maté tea (maté). The optimisation of two extraction methods, namely liquid-liquid extraction and accelerated solvent extraction, was carried out. Both optimised methods were validated using a certified reference material of fine dust and the results were within the expanded uncertainties at 95% confidence level. Recoveries of 99.2-106.7% with RSD of measurements of 1.1-2.3% were achieved for benz[a]anthracene. Recoveries of 95.7-101.9% with RSD of measurements of 0.4-1.4% were achieved for benzo[a]pyrene. The validated methods were applied for the extraction of benz[a]anthracene and benzo[a]pyrene in maté powder from NIST. A metrological approach was undertaken to ensure the traceability of measurement results. The uncertainties associated with the results were rigorously evaluated and also reported herein. Graphical abstract Quantification of benz[a]anthracene and benzo[a]pyrene using IDMS.

[Determination of benzopyrene in red clover extract by high performance liquid chromatography with spectrofluorescence detector].

OBJECTIVE: To establish a high performance liquid chromatography method with spectrofluorescence detector for the quantitative analysis of benzopyrene in red clover extract. METHOD: Analysis was performed on Hypersil C18 column (4. 6 mm x 200 mm, 5 microm) with acetonitrile and water (70: 30) as mobile phase; The excitation wavelength and emission wavelengh were 368 nm and 405 nm, respectively; Flow rate was 1.0 mL x min(-1). RESULT: The linear range was 0.93-37.2 ng x mL(-1), and r = 0.9992 (n = 5). The average recovery of benzopyrene was 85.2% (n = 9). CONCLUSION: The method was convenient and accurate with good recovery.

Humic acid-bonded silica as a novel sorbent for solid-phase extraction of benzo[a]pyrene in edible oils.

A novel solid-phase extraction (SPE) sorbent, humic acid-bonded silica (HAS), was prepared. Humic acids (HAs) were grafted onto silica matrices via an amide linkage between humyl chloride and the amido terminus of 3-aminopropyltrimethoxysilane (APTS)-silica gel. The resulting material was characterized by Fourier transform infrared spectrometer, elemental analysis, and nitrogen adsorption analysis. This sorbent exhibits an excellent adsorption capacity for some electron-abundant analytes owing to its peculiar structure. In this paper, we choose benzo[a]pyrene (BaP) in oil as a probe to validate the adsorption capacity of the material. Thus a fast, cheap and simple SPE method with humic acid-bonded silica cartridge for edible oil clean-up, followed by high-performance liquid chromatography (HPLC) with fluorescence detection was established. The effects of experimental variables, such as washing and elution solvents, and the amount of sorbents have been studied. The recoveries of BaP in edible oils spiked at 0.2-100 microg kg(-1) were in the range of 78.8-102.7% with relative standard deviations ranging between 1.3 and 9.3%; the limit of detection was -0.06 microg kg(-1).

Rapid determination of benzo(a)pyrene in olive oil samples with solid-phase extraction and low-pressure, wide-bore gas chromatography-mass spectrometry and fast liquid chromatography with fluorescence detection.

Benzo(a)pyrene (B(a)P) was extracted from olive oil using solid-phase extraction on columns filled with Florisil and Nucleoprep C18. The extracts were analyzed with GC-MS, using standard capillary column and low-pressure wide-bore column (LP-GC-MS), as well as with HPLC on standard column and short donor-acceptor complex chromatography (DACC) column. Quantitation was done with isotope dilution method (GC-MS and LP-GC-MS) or with internal standard benzo(k)fluoranthene (HPLC). Limits of detection were 1 ng/g for GC-MS on standard column, 1.6 ng/g on LP-column, 0.5 ng/g for HPLC on standard column, and 0.3 ng/g on DACC column, respectively. The applied extraction method allowed handling over 50 samples per day and assured recovery over 80%. Matrix solid-phase dispersion, tried as an alternative isolation method, appeared less advantageous. Fast chromatographic methods (LP-GC-MS and HPLC on DACC) made it possible to reduce analysis time to 8 and 5 min, respectively. The method was applied to routine analysis of B(a)P in olive oil samples.

Valoración de trazas de benzo(a)pireno como contaminante ambiental por espectrometría de luminiscencia sincrónica / Valoration of traces of benzo(a)pyrene as environmental by synchronous luminescence spectrometry

Es bien conocida la actividad carcinogénica de trazas de benzo (a) pireno (BAP), por lo tanto es importante determinar las condiciones para la mayor y selectividad en medios complejos tales como petróleo y sedimentos marinos. La espectrometría de fluorescencia sincrónica ha resultado ser uno de los mejores métodos para llevar a cabo estos objetivos. Para este método el delta gama es el parámetro principal. En este trabajo se muestra que cuando delta gama = 107 nm puede ser valorado BAP hasta 12 microng/g de petróleo sin tratamiento previo, mientras que para sedimentos marinos, bajo condiciones adecuadas de extracción, permiten valorarse hasta 0,7 ng/g de muestra (AU)

Valoración de trazas de benzo(a)pireno como contaminante ambiental por espectrometría de luminiscencia sincrónica / Valoration of traces of benzo(a)pyrene as environmental by synchronous luminescence spectrometry

Es bien conocida la actividad carcinogénica de trazas de benzo (a) pireno (BAP), por lo tanto es importante determinar las condiciones para la mayor y selectividad en medios complejos tales como petróleo y sedimentos marinos. La espectrometría de fluorescencia sincrónica ha resultado ser uno de los mejores métodos para llevar a cabo estos objetivos. Para este método el delta gama es el parámetro principal. En este trabajo se muestra que cuando delta gama = 107 nm puede ser valorado BAP hasta 12 microng/g de petróleo sin tratamiento previo, mientras que para sedimentos marinos, bajo condiciones adecuadas de extracción, permiten valorarse hasta 0,7 ng/g de muestra