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We screened and identified an endophytic bacterium that could efficiently degrade PAHs, which would expand the library of polycyclic aromatic hydrocarbons (PAHs) degrading microorganisms and reduce the pollution risk of crops. Its degradation mechanism and colonization performance were preliminarily examined. The results showed that strain PX1 belonged to Stenotrophomonas maltophilia . The strain had broad spectrum ability to remove PAHs. In PAH mineral salt (MS) media, almost 100% naphthalene was degraded by strain PX1 after 7-d incubation. In a cultivation system solely containing phenanthrene of 50.0 mg·L -1 , pyrene of 20.0 mg·L -1 , fluoranthene of 20.0 mg·L -1 or benzo[a]pyrene of 10.0 mg·L -1 , the degradation efficiency of phenanthrene, pyrene, fluoranthene and benzo[a]pyrene by strain PX1 reached 72.6%, 50.7%, 31.9%, and 12.9%, respectively. Pyrene was selected as PAHs model to study the degradation characteristics of strain PX1. Enzyme activity tests showed that the activities of phthalate dioxygenase, catechol-1,2-dioxygenase, and catechol-2,3-dioxygenase in strain PX1 were induced by pyrene. Some metabolic intermediates such as 4,5-epoxypyrene, 4,5-dihydroxypyrene, gentilic acid/protocatechuic acid, salicylic acid, cis-hexadienedioic acid/2-hydroxymyxofuroic acid semialdehyde, cis-2'-carboxyphenylpyruvic acid, 1-hydroxy-2-naphthoic acid, and salicylaldehyde were detected during the degradation of pyrene by strain PX1. Results of the seed soaking experiment showed that strain PX1 could efficiently colonize in Ipomoea aquatic and Triticum aestivum. After inoculated with strain PX1, the growth of I. aquatic and T. aestivum was significantly increased, and the pyrene concentration in I. aquatic , T. aestivum and MS media was reduced by 29.8%-50.7%, 52.4%-67.1% and 8.0%-15.3%, respectively. Our results suggested that strain PX1 degraded pyrene mainly through 'salicylate pathway' and 'phthalate pathway', and could be colonized into plants and promote plant growth.

A method based on precolumn derivatization along with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the determination of ethylenethiourea residues in tea. The sample was extracted using acetonitrile; the extracting solution was purified by matrix-dispersed solid phase extraction and precolumn derivatization using 9-fluorenylmethyl chloroformate (FMOC-CL). The UPLC separation was carried out on an Acquity BEH C18 column (100 mm×2.1 mm, 1.7 μm) and quantified using the isotope internal standard method. The mobile phase was 0.1% (v/v) formic acid and acetonitrile. For tea samples, the detection limit of this method was 1.3 μg/kg and the limit of quantitation was 4.2 μg/kg. The recoveries were in the range 97.7%-107.5% with relative standard deviation (RSD) of 2.1%-10.0% ( n =6). The linear correlation coefficient ( r ) was 0.9993 over the concentration range 1.0-203.4 μg/L. This method showed high sensitivity, good reproducibility, and qualitative and quantitative accuracy, and could be suitable for the detection of ethylenethiourea residues in tea.

A method has been developed for the determination of glyphosate (GLY), glufosinate (GLUF), and the main metabolite aminomethylphosphonic acid (AMPA) residues in dry tea based on ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) coupled with pre-column derivatization. A systematic study of the effects of pretreatment methods including extraction and purification procedures was designed and carried out for the determination of GLY, GLUF, and AMPA. The results indicated that the optimal pretreatment method was as follows:the tea sample was first extracted by water in vortex, and then purified by a cation exchange solid-phase extraction column with the elution of 0.5% (v/v) formic acid aqueous solution. Finally, the eluant was derivatized by 9-fluorenylmethyl chloroformate, and the target compounds were separated on a C 18 chromatographic column and analysed by UPLC-MS/MS (ESI + ). GLY, GLUF, and AMPA showed good linearity in the range of 1-100 μ g/L, with correlation coefficients above 0.991. The limits of detection and limits of quantification were found to be 0.0160-0.0300 mg/kg and 0.0530-0.100 mg/kg, respectively. The average spiked recoveries of GLY, GLUF, and AMPA varied from 78.3% to 108% at three spiked levels (0.0500, 0.400, and 1.20 mg/kg), while the relative standard deviations ranged from 5.46% to 9.63%. The proposed method was utilized to detect 837 batches of tea samples. The detection ratios of GLY, GLUF, and AMPA were 3.46%, 0.24%, and 4.42%, respectively, while 0.24% of the investigated tea samples had values above maximum residue limits. The developed method is simple, rapid, sensitive, and accurate for the determination of GLY, GLUF, and AMPA in dry tea and may be used for routine analysis.

A method for the simultaneous determination of 15 polycyclic aromatic hydrocarbons in cigarette filter was developed by isotope internal standard combined with gas chromatography-tandem mass spectrometry. The cigarette filters were extracted with dichloromethane, and the extract was filtered with 0.22 μm organic phase membrane. The samples were isolated by DB-5MS column (30 m×0.25 mm, 0.25 μm) and detected using multiple reaction monitoring mode of electron impact source under positive ion mode. The linearities of the 15 polycyclic aromatic hydrocarbons (acenapthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, ben[ a ]anthracene, chrysene, benzo[ b ]fluoranthene, benzo[ k ]fluoranthene, benzo[ a ]pyrene, dibenzo[ a,h ]anthracene, benzo[ g,h,i ]perylene and indeno[1,2,3- c,d ]pyrene) were good, and the correlation coefficients ( R 2 ) ranged from 0.9914 to 0.9999. The average recoveries of the 15 polycyclic aromatic hydrocarbons were 81.6%-109.6% at low, middle and high spiked levels, and the relative standard deviations were less than 16%, except that the relative standard deviation of fluorene at the low spiked level was 19.2%. The limits of detection of the 15 polycyclic aromatic hydrocarbons were 0.02 to 0.24 ng/filter, and the limits of quantification were 0.04 to 0.80 ng/filter. The method is simple, rapid, accurate, sensitive and reproducible. It is suitable for the quantitative analysis of the 15 polycyclic aromatic hydrocarbons in cigarette filters.

A method for the determination of four polycyclic aromatic hydrocarbons (PAHs) such as benzo[ a ]anthracene, chrysene, benzo[ b ]fluoranthene and benzo[ a ]pyrene in olive oil by high performance liquid chromatography-fluorescent detection (HPLC-FLD) was developed. The olive oil samples were diluted with isopropanol and cleaned-up by a solid phase extraction cartridge with π-π specificity. Critical isomers were separated by gradient elution with water-acetonitrile on an Agilent ZORBAX Eclipse PAH column (100 mm×2.1 mm, 1.8 μ m). The calibration was performed by the use of matrix-matched calibration standards. The results showed that there were good linear relationships for the four PAHs in the range of 2.4-40 μ g/L with correlation coefficients of 0.9990-0.9999. The limits of quantification (LOQs) ranged from 0.147 to 0.413 μ g/L, and the recoveries of the spiked samples ranged from 95.5% to 103.2%. The intra-day and inter-day precisions were in the ranges of 0.10%-1.69% and 2.48%-2.93% ( n =5), respectively. The method has the characteristics of high sensitivity, low detection limit and good precision, and is suitable for rapid and accurate quantitative detection of the four PAHs in olive oil.

Objective: To investigate the relationship between urinary polycyclic aromatic hydrocarbon metabolite and cell cycle of lymphocyte in coke oven workers. Methods: 437 coke oven workers and 163 work-ers in water treatment department were recruited in this study. Flow cytometry was used to detect the cell cycle of lymphocyte. For the measurement of urinary metabolites, urine samples were treated with β-glucuronidase and analyzed using HPLC with a fluorescence detector. Results: The concentrations of urinary 2-naphthol, 2-hydroxyfluorene, 9-phenanthrol and 1-hydroxypyrene l in coke oven workers were significantly higher than those in control group ( P <0.01) . The distributions of cell cycle were analyzed in high exposure group (the content of urinary metabolites high than P 75) and low exposure group (the content of urinary metabolites low than P 25) . According to the content of 1-hydroxypyrene, the proportions of S phase in high exposure group were significant-ly higher than those of low exposure group ( Z =-2.496, P =0.013) , but the proportions of G0/G1 phase were sig-nificantly lower than low exposure group ( Z =-2.074, P =0.038) . The similar results were not been found in other hydroxylated metabolites as internal exposure group. Conclusion: Increasing levels of urinary 1-hydroxypyrene might resulting in cell cycle of lymphocyte disorders, mainly for G0/G1 phase shorten and S phase arrest.

In order to understand the contamination characteristics of PAHs in different environmental mediums of karst underground river, the authors chose the Qingshuiquan underground river as the study object. Based on the data of air, groundwater, sediment and soil samples collected during the same period from 2013 to 2014, contrastive analysis was conducted in light of the component spectra, the distribution features and the characteristic ratios as well as the chemical and physical properties of 16 kinds of PAHs. The results showed that 3 kinds of PAHs with 2-3 rings (naphthalenes, phenanthrene and fluoranthene) were dominant in the air and underground river water, which accounted for 71.66% and 54.84% of the total PAHs. And PAHs with 4-6 rings were dominant in the soil and sediment of the underground river, which accounted for 54.26% and 65.06% of the total .PAHs. The distribution of PAHs in environmental mediums along the underground river indicated that the mean concentration PAHs in upstream area was less than that of midstream, and that of midstream was less than that of downstream, because of pollution discharge and absorption. The ratios of specific PAHs indicated that the PAHs sources in upstream rural area mainly came from the combustion of grassy, wood and coal, the PAHs sources in Ganhuai village were mainly originated from petroleum, and the PAHs sources in the outlet of the underground river mainly came from both petroleum and its combustion.

In order to study the contamination by the U. S. EPA 16 priority polycyclic aromatic hydrocarbons (PAHs) in the soil of the end-of-life vehicle dismantling area, soil samples with vertical depth of 0-1 000 cm were collected and analyzed. The concentrations of EPA 16 priority PAHs were determined in soils samples. The results showed that total concentrations of PAHs were 991 ng.g-1 in surficial samples, with the highest concentrations detected for pyrene, benzo [a]anthracene and fluorine, reaching 11 820, 1 234 and 1 083 ng.g-1, respectively. The soils with the depth range of 0-10 cm were heavily polluted by PAHs, and the soils in the depth range of 50-350 cm were moderately or slightly polluted by PAHs. It seems that there was no PAHs pollution when the soil depth was over 400 cm. However, it was noted that the total concentration of 7 carcinogenic PAHs including chrysene (Chr), benzo [a] anthracene (BaA), Benzene and (b) fluoranthene(BbF) , Benzene and (k) fluoranthene (BkF), Benzo [a] pyrene (BaP), Diphenyl and [a, h] anthracene(DahA) , Indene and [1,2,3-CD] pyrene (IcdP) was still as high as 34.15 ng.g-1 in soil with a depth of 850 cm. The contents of PAHs decreased sharply with the increase in vertical depth. Low-ring PAHs such as phenanthrene, Fluoranthene and acenaphthene became the priority compounds when the depth was over 300 cm. The ratios of Phe/Ant and Fla/Pyr demonstrated that the PAHs in the soil profiles could be primarily sourced from petroleum pollution.

The sample capacity is an important parameter of the gas chromatographic column. On a sol-gel-coated poly(dimethylsiloxane) (PDMS) capillary column and a conventional PDMS capillary column the probes undecane and fluoranthene were injected and the column efficiency was measured. After the injection amount was increased to a certain point, the column efficiency was reduced rapidly, and the amount that causes the efficiency reduction of ten percent is called the sample capacity of the column. The results show that the sample capacity of the sol-gel PDMS column is much higher than that of the conventional PDMS column. The reasons of higher sample capacity of a sol-gel column have been studied.

Curcumin is a coloring additive used in food, which has many biological functions. In order to provide basic information on its anticarcinogenicity, the antimutagenicity of curcumin was determined by Ames test and micronuclei test. The results indicated that curcumin (60-250 micrograms/plate) inhibited the revert mutant induced by 2, 7-diaminofluorene (2AF) with S-9 in TA98 and in TA100. The inhibitory rates are 29.5%-55.9% and 37.5%-59.1% respectively. Before the injection of cyclophosphamide (CP), mice were given with curcumin (60, 120, and 240 mg/kg) orally once a day for a week. The results revealed that curcumin reduced the micronuclei formation induced by CP. The inhibitory rates of curcumin are 43.7%, 56.9%, and 63.9% respectively, which are different from that of the positive control significantly.