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Occurrence of Rhodamine B (RhB) contamination in paprika caused by agricultural materials during the vegetation process has been reported. It may transfer during the process of active compounds extraction, and eventually exist in final products. Herein, the re-distribution of RhB during the extraction process was assessed in terms of RhB contents, as well as mass, color value and capsaicinoids yield of each process. Results revealed that natural RhB contamination at 0.55-1.11µg/kg originated from raw paprika fruit then transferred with the extraction proceeded. About 95.5% of RhB was found in red oleoresin. After separation of red oleoresin, 91.6% of RhB was remained in capsicum oleoresin, only 3.7% in paprika red. These results were consistent with total capsaicinoids recovery of each product. The RhB levels in edible capsicum oleoresin in our present study at 0.01-0.34µg/kg did not exceed the legal limits established by the European Union.

Tomato peel is a promising source of lycopene. Benzo(a)pyrene, benzo(a)anthracene, benzo(b)fluoranthene, and chrysene (PAH 4) are polycyclic aromatic hydrocarbons (PAHs) classed as priority pollutants by the European Union that can be sorbed by tomato peel and transferred to lycopene products. Here, the transfer of PAH 4 to extracted lycopene was assessed. Between 77.69% and 102.99% of PAH 4 in tomato peel was transferred to tomato oleoresin. The PAH transfer rate was closely related to the log (octanol-water partition coefficient). PAH partitioning depended on the PAH solubility in the different phases used. Only 0.028%-0.058% of the PAHs entered lycopene crystals, the rest remaining in the residue. This indicated that crystallization efficiently excluded PAH 4. Lycopene crystals 96.71% pure were produced that could be used in various commercial products. An exposure and risk assessment indicated that PAH 4 in lycopene do not pose strong risks to people consuming lycopene microcapsules.

This paper reports on the environmental rhodamine B (RhB) contamination in capsicum caused by agricultural materials during the vegetation process. Ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was applied to detect 64 capsicum samples from China, Peru, India and Burma. Results demonstrated that RhB was found in all samples at low concentrations (0.11-0.98 μg/kg), indicating RhB contamination in capsicums is probably a ubiquitous phenomenon. In addition, studies into soils, roots, stems and leaves in Handan of Hebei province, China showed that the whole ecologic chain had been contaminated with RhB with the highest levels in leaves. The investigation into the agricultural environment in Handan of Hebei province and Korla of Xinjiang province, China demonstrated that the appearances of RhB contamination in the tested capsicums are mainly due to the agricultural materials contamination. The study verified that environmental contamination should be an important origin for the RhB contamination in capsicum fruits.

Experiments were conducted to assess the role of colonization of alfalfa roots by an arbuscular mycorrhizal (AM) fungus (Glomus etunicatum) in conjunction with a non-ionic surfactant (Triton X-100) in dissipation of phenanthrene in a soil spiked with phenanthrene at 0, 2.5, 5.0 and 10.0 mg kg(-1). After plant harvest the residual phenanthrene concentration in the soil decreased markedly. Mycorrhizal treatment enhanced phenanthrene dissipation in the rhizosphere and bulk soils irrespective of phenanthrene application rate. Addition of Triton X-100 resulted in the highest phenanthrene concentration in the rhizosphere soil among the treatments, while the lowest phenanthrene concentration in the bulk soil was obtained by AM inoculation and amendment with Triton X-100. AM inoculation and addition of the surfactant consistently promoted phenanthrene dissipation in the soil and decreased the microbial biomass based on phospholipid fatty acid (PLFA) analysis. PLFA profiles demonstrated that AM inoculation together with addition of Triton X-100 altered the microbial community structure in the rhizosphere soil. The results of this study provide a reference value for phytoremediation of soil contaminated by organic pollutants. (c) 2008 Elsevier B.V. All rights reserved.

The voltammetric behavior of trepibutone at a pencil graphite electrode (PGE) is investigated by cyclic and square-wave voltammetry in B–R buffers (pH 1.81–11). Two pairs of well-defined reversible peaks are observed at 1.06 and 1.24 V over the pH range of 1.81–6.80, which are attributed to the one-electron transfers without proton in two different chemical forms of trepibutone, protonated and non-protonated. The cathodic peaks correspond to a one-electron reduction of the carbonyl of the benzoyl group, and the anodic peaks correspond to a one-electron oxidation of its free radical. In addition, when the trepibutone concentration is higher, another reversible peak at 0.39–0.26 V is observed in the pH range of 1.81–3.00, corresponding to the transfer of two electrons and two protons, which may be due to the dimer of the trepibutone free radical. Based on the oxidation peak at 1.06 V in B–R buffer (pH 1.81), a square-wave voltammetric method is proposed for the determination of trepibutone. A linear relationship is obtained from 0.24 to 10 μg mL −1 with a detection limit of 20 ng mL −1 . The PGE exhibits the best reproducibility and highest sensitivity without any additional procedure for the renewal of the electrode surface. The proposed method is applied to the determination of trepibutone in pharmaceutical formulations.