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The work presented here refers firstly to solid-state UV-MALDI-Orbitrap-mass spectrometric analysis of fluroxypyr (A) and triclopyr (B) in soils under laboratory conditions. The experimental design has involved the following: (a) determination of analytes A and B in polycrystalline composites of organic materials 1-7, based on 2-piperidine (pyrrolidine or piperazine)-1-yl-ethyl ammonium salts in order to determine the effect of sample preparation techniques on method performance using commercial herbicide formulations and (b) analysis of non-(X j,k,l (i) ) and sterilized (Y j,k,l (i) ) soil samples (i-fold rate 1, 10, 100, or 1,000; j-pesticide type A or B; k-time (0, 5, 10, 20, and 50 days) and l = 1-3 replicated samples) having clay content ∈ 5.0-12.0 %, silt ∈ 23.0-51.1 %, sand ∈ 7.2-72.0 %, and pH ∈ 4.0-8.1. In order to obtain a high representativeness of the data toward real-field experiments, the pollution scheme has involved 1-, 10-, 100-, and 1,000-fold rates. The firstfold rate has concentration of pollutant A of 2.639 × 10(-4) g in 625 cm(2) soil horizon of 0-25 cm(2) (5 cm depth) according to registration report (PSM-Zulassungbericht) of German Federal Office of Consumer Protection and Food Safety (Bundesamt für Verbraucherschutz und Lebensmittelsicherheit) 6337/26.10.2009. The experimental design has involved quincunx systematic statistical approach for collection of soil samples. The performance has been compared with the corresponding statistical variable obtained, using an independent HPLC-ESI-(APCI-)-MS/MS analysis.

Rationale: Sesquiterpene pyridine alkaloids are a large group of highly oxygenated sesquiterpenoids that have attracted attention in the fields of medicine because of their significant biological activities., Methods: Reference compounds including 14 sesquiterpene pyridine alkaloids and one dihydroagarofuran ester were analyzed by collision-induced dissociation tandem mass spectrometry (CID-MS/MS). A high-performance liquid chromatography/electrospray ionization (HPLC/ESI)-MS/MS method at two collision energies was adopted to investigate the botanical extracts of Tripterygium wilfordii., Results: For 15 reference compounds, in the high mass range, the product ions were formed by the loss of side chains or H2 O. In the low mass range, the high-abundance product ions at m/z 206, 204, or 194 were the characteristic ions of the pyridine moiety. The characteristic product ion at m/z 310 was formed through an ion-neutral complex intermediate. Fifty-four sesquiterpenoid derivatives, including 50 sesquiterpene pyridine alkaloids, were identified or tentatively characterized in botanical extracts of T. wilfordii based on their elemental constituents, characteristic fragmentation patterns, and the major product ion profiles of the reference compounds ascertained with HPLC/ESI-MS/MS at two collision energies. It seems that isocratic energy was appropriate for the untargeted analysis of compounds with molecular weights exceeding 800 Da, whereas a linear gradient energy vs molecular weight was suitable for those compounds with molecular weights below 800 Da., Conclusions: The HPLC/ESI-MS/MS method, combining characteristic fragmentation patterns and the profiles of the product ions generated at different collision energies, is an effective technique for characterizing untargeted compounds., (Copyright © 2015 John Wiley & Sons, Ltd.)

The original analytical method for the simultaneous determination and confirmation of neonicotinoids insecticides (imidacloprid, clothianidin, acetamiprid, thiametoxam, thiacloprid, nitenpyram, dinotefuran) and some of their metabolites (imidacloprid guanidine, imidacloprid olefin, imidacloprid urea, desnitro-imidacloprid hydrochloride, thiacloprid-amid and acetamiprid-N-desmethyl) in honey bee and honey was developed. Preparation of honey bee samples involves the extraction with mixture of acetonitrile and ethyl acetate followed by cleaned up using the Sep-Pak Alumina N Plus Long cartridges. Honey samples were dissolved in 1% mixture of acetonitrile and ethyl acetate with addition of TEA, then extracts were cleaned up with Strata X-CW cartridges. The identity of analytes was confirmed using liquid chromatography tandem mass spectrometry. All compounds were separated on a Luna C18 column with gradient elution. The whole procedure was validated according to the requirements of SANCO 12571/2013. The average recoveries of the analytes ranged from 85.3% to 112.0%, repeatabilities were in the range of 2.8-11.2%, within-laboratory reproducibility was in the range of 3.3-14.6%, the limits of quantitation were in the range of 0.1-0.5μgkg(-1), depending of analyte and matrices. The validated method was successfully applied for the determination of clothianidin, imidacloprid and imidacloprid urea in real incurred honey bee samples and clothianidin in honey., (Copyright © 2015 Elsevier B.V. All rights reserved.)

A derivatization LC-MS/MS method was developed and qualified for the trace level quantification of 2-hydroxypyridine N-oxide (HOPO). HOPO is a coupling reagent used in the syntheses of active pharmaceutical ingredients (APIs) to form amide bonds. HOPO was recently confirmed to generate a positive response in a GLP Ames bacterial-reverse-mutation test, classifying it as a mutagenic impurity and as such requiring its control in APIs to the threshold of toxicological concern (TTC). The derivatization reagent 5-dimethylamino-1-naphthalenesulfonyl chloride (dansyl chloride) was used in a basic solution to convert HOPO into the corresponding dansyl-derivative. The derivative was separated from different APIs and reagents by liquid chromatography. The detection of the HOPO dansyl-derivative was achieved by mass spectrometry in selected reaction monitoring (SRM) mode. The LC-MS/MS method had a reporting limit of 0.1ng/mL HOPO, which corresponds to 0.1ppm HOPO relative to an API at 1mg/mL, and a linearity range of 0.1-25ng/mL HOPO analyte. Recoveries of HOPO standards spiked into three different API matrices at 0.2, 1.2, and 20ppm levels were all within 90-100%. An SRM-based confirmatory methodology using the ratios of two fragment ions at three CID energies was developed to verify the identity of HOPO when present at ≥0.6ppm. This identity confirmation can be employed to prevent potential false positive detection of mutagenic impurities at trace level. It can be broadly applicable for the confirmation of analytes when the analytes generate at least two major fragments in tandem mass spectrometry experiments., (Copyright © 2015 Elsevier B.V. All rights reserved.)

A facile aptasensor has been developed for the colorimetric detection of acetamiprid by using the hemin-functionalized reduced graphene oxide (hemin-rGO) composites. The as-prepared hemin-rGO composites possessed both the ability of rGO to physically adsorb the aptamers and the peroxidase-like activity of hemin that could catalyse 3,3,5,5-tetramethylbenzidine (TMB) in the presence of H2O2, to produce a solution with blue color. The well-dispersed hemin-rGO composites coagulated completely at the proper salt concentration; however, the coagulation of hemin-rGO was vanished when abundant aptamers were adsorbed on its surface because the attached negatively charged DNA backbone increased individual hemin-rGO electrostatic repulsion. In the detection scheme, acetamiprid with different concentrations was firstly incubated with the same amount of aptamer. The more acetamiprid in the tested solution, the less free aptamers were absorbed on the hemin-rGO surface, making the composites coagulate to a higher degree in the presence of the optimum NaCl concentration. As a consequence, the content of hemin-rGO in the supernatant was decreased after centrifugation, which catalysed oxidation of TMB in the presence of H2O2 to produce light blue color with a low absorbance. The color variation relavant to the acetamiprid concentration can be judged by the naked eyes and easily monitored by the inexpensive UV-vis spectrometer. Such designed aptasensor displayed a linear response for acetamiprid in the range from 100nM to 10μM with a detection limit of 40nM (S/N=3). This colorimetric aptasensing platform offers great advantages including the simple operation process, low-cost portable instrument, and user-friendly applications., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Rationale: Neonicotinoids are widely used insecticides which have been shown to affect the memory and learning abilities of honey bees, and are suspected to play a part in the unexplainable, large-scale loss of honey bee colonies. Fast methods, such as ambient mass spectrometry (MS), for their analysis from a variety of matrices are necessary to control the use of forbidden products and study the spreading of insecticides in nature., Methods: The feasibilities of two ambient MS methods, desorption electrospray ionization (DESI) and desorption atmospheric pressure photoionization (DAPPI), for the analysis of five most used neonicotinoid compounds, thiacloprid, acetamiprid, clothianidin, imidacloprid and thiamethoxam, were tested. In addition, DAPPI was used to analyze fresh rose leaves treated with commercially available thiacloprid insecticide and dried and powdered turnip rape flowers, which had been collected from a field treated with thiacloprid-containing insecticide., Results: DAPPI was found to be more sensitive than DESI, with 2-11 times better signal-to-noise ratios, and limits of detection at 0.4-5.0 fmol for the standard compounds. DAPPI was able to detect thiacloprid from the rose leaves even 2.5 months after the treatment and from the turnip rape flower samples collected from a field. The analysis of plant material by DAPPI did not require extraction or other sample preparation., Conclusions: DAPPI was found to be suitable for the fast and direct qualitative analysis of thiacloprid neonicotinoid from plant samples. It shows promise as a fast tool for screening of forbidden insecticides, or studying the distribution of insecticides in nature., (Copyright © 2015 John Wiley & Sons, Ltd.)

Introduction: Insurance agencies might request laboratories to differentiate whether a deceased has been a smoker or not to decide about refunding of his nonsmoker rate. In this context, the question on a solid proof of tobacco alkaloids and major metabolites in tissues came up. Currently, an appropriate assay is still lacking to analyze tissue distribution in smokers or nonsmokers. Nicotine (NIC), nornicotine (NNIC), anatabine (ATB), anabasine (ABS), and myosmine (MYO) are naturally occurring alkaloids of the tobacco plant; most important phase I metabolites of NIC are cotinine (COT), norcotinine (NCOT), trans-3'-hydroxycotinine (HCOT), nicotine-N'-oxide (NNO), and cotinine-N-oxide (CNO). An analytical assay for their determination was developed and applied to five randomly selected autopsy cases., Methods: Homogenates using 500 mg aliquots of tissue samples were analyzed by liquid chromatography/tandem mass spectrometry following solid phase extraction. The method was validated according to current international guidelines., Results: NIC, COT, NCOT, ABS, ATB, and HCOT could be detected in all tissues under investigation. Highest NIC concentrations were observed in the lungs, whereas highest COT concentrations have been found in the liver. MYO was not detectable in any of the tissues under investigation., Conclusions: The assay is able to adequately separate isobaric analyte pairs such as NIC/ABS/NCOT and HCOT/CNO thus being suitable for the determination of tobacco alkaloids and their phase I metabolites from tissue. More autopsy cases as well as corresponding body fluids and hair samples will be investigated to differentiate smokers from nonsmokers.

1.(1S)-1-phenyl-2-(pyridin-2-yl)ethanamine (lanicemine; AZD6765) is a low-trapping N-methyl-d-aspartate (NMDA) channel blocker that has been studied as an adjunctive treatment in major depressive disorder. The metabolism and disposition of lanicemine was determined in six healthy male subjects after a single intravenous infusion dose of 150 mg [(14)C]-lanicemine. 2.Blood, urine and feces were collected from all subjects. The ratios of Cmax and AUC(0-∞) of lanicemine to plasma total radioactivity were 84 and 66%, respectively, indicating that lanicemine was the major circulating component with T1/2 at 16 h. The plasma clearance of lanicemine was 8.3 L/h, revealing that lanicemine is a low-clearance compound. The mean recovery of radioactivity from urine was 93.8% of radioactive dose. 3.In urine samples, 10 metabolites of lanicemine were identified. Among which, an O-glucuronide conjugate (M1) was the most abundant metabolite (∼11% of the dose in excreta). In plasma, the circulatory metabolites were identified as a para-hydroxylated metabolite (M1), an O-glucuronide (M2), an N-carbamoyl glucuronide (M3) and an N-acetylated metabolite (M6). The average amount of each of metabolite was less than 4% of total radioactivity detected in plasma or urine. 4.In conclusion, lanicemine is a low-clearance compound. The unchanged drug and metabolites are predominantly eliminated via urinary excretion.

Purpose: The new analytical method of qualitative and quantitative determination of zolpidem and qualitative analysis of its main metabolite in blood and oral fluid samples was developed., Materials and Methods: Sample preparation was carried out using a polymeric ion-exchange sorbent in solid phase extraction (SPE). Analysis was realized using liquid chromatography with mass spectrometry detection (LC/MS). The method was validated in terms of few parameters. LOD, LOQ, linearity, precision, selectivity, ion suppression and stability were estimated., Results: Obtained method showed good linearity with determination coefficient (R(2)) of 0.9989 and 0.9998 for blood and oral fluid samples, respectively. LOD and LOQ of zolpidem were 0.2ng/mL and 1.0ng/mL, respectively, for both blood and oral fluid samples. SPE method recovery varies from 79.9±12.6 to 104.1±1.77 for blood sample and 80.2±0.48 to 103.8±1.51 for oral fluid sample. Samples collected from patients taking zolpidem with a prescription were analyzed. Detection of zolpidem was possible after 15h from ingestion of 10mg zolpidem tartrate in both types of samples., Conclusion: The developed method allows quantitation of zolpidem in therapeutic and subtherapeutic range as well as qualitative analysis of its main metabolite in blood and oral fluid samples. This method meets criteria required for bioanalytical applications and can be used for clinical and forensic purposes., (Copyright © 2015 Medical University of Bialystok. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.)

Four simple, sensitive and selective spectrophotometric methods are presented for determination of Zopiclone (ZPC) and its impurity, one of its degradation products, namely; 2-amino-5-chloropyridine (ACP). Method A is a dual wavelength spectrophotometry; where two wavelengths (252 and 301 nm for ZPC, and 238 and 261 nm for ACP) were selected for each component in such a way that difference in absorbance is zero for the second one. Method B is isoabsorptive ratio method by combining the isoabsorptive point (259.8 nm) in the ratio spectrum using ACP as a divisor and the ratio difference for a single step determination of both components. Method C is third derivative (D(3)) spectrophotometric method which allows determination of both ZPC at 283.6 nm and ACP at 251.6 nm without interference of each other. Method D is based on measuring the peak amplitude of the first derivative of the ratio spectra (DD(1)) at 263.2 nm for ZPC and 252 nm for ACP. The suggested methods were validated according to ICH guidelines and can be applied for routine analysis in quality control laboratories. Statistical analysis of the results obtained from the proposed methods and those obtained from the reported method has been carried out revealing high accuracy and good precision., (Copyright © 2014 Elsevier B.V. All rights reserved.)

We report here that tobacco-specific nitrosamines (TSNAs) are produced from specific tobacco alkaloids during water chloramination. To identify the specific precursors for the formation of specific TSNAs in drinking water, we have developed a solid-phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) method for simultaneous determination of five TSNAs and three tobacco alkaloids. Using this method, we detected nicotine (NIC) at 15.1 ng/L in a source water. Chloramination of this source water resulted in the formation of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) (0.05 ng/L) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) (0.2 ng/L) along with the reduction of NIC to 1.1 ng/L, suggesting that NNK and NNAL were formed from NIC. To confirm that tobacco alkaloids are the precursors of TSNAs, we chloraminated water-leaching samples of tobacco from three brands of cigarettes and found that the formation of TSNAs coincides with the reduction of the alkaloids. Chloramination of individual alkaloids confirms that NNK and NNAL are produced from NIC, N-nitrosonornicotine (NNN) from nornicotine (NOR), and N-nitrosoanabasine (NAB) from anabasine (ANA). Furthermore, we have identified specific intermediates of these reactions and proposed potential pathways of formation of TSNAs from specific alkaloids. These results confirm that NNK and NNAL are the disinfection byproducts (DBPs) resulting from NIC in raw water.

Heterocyclic aromatic amines such as PHIP are formed during the heat processing of food. PHIP undergoes bacterial metabolism leading to 7-hydroxy-5-methyl-3-phenyl-6,7,8,9-tetrahydropyrido[3',2':4,5]imidazo[1,2-a]pyrimidin-5-ium chloride (PHIP-M1) as main metabolite. We developed an LC-MS method with automated sample preparation by online-solid-phase-extraction for the simultaneous quantification of PHIP and its mammalian and bacterial metabolites N-hydroxy-PHIP, 4-OH-PHIP and PHIP-M1 in biological samples. The method was used to investigate the transport of PHIP-M1 through a Caco-2 cell monolayer. The experiments show that PHIP-M1 rapidly crosses the cell monolayer and that PHIP-M1 is a substrate for P-glycoprotein and the multiple drug resistance 2 transporter. The intestinal absorption of PHIP-M1 is comparable with that of PHIP and a moderate to high bioavailability has to be expected. Thus, not only the human metabolites of PHIP but also the bacterial metabolite PHIP-M1 formed in the gut could contribute to the toxic effects of PhIP., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Molecular mass distributions of series of compounds found in exhaled breath after smoking are compared between the direct-breath analysis by extractive electrospray ionization and the analysis of exhaled breath condensate by direct-infusion electrospray ionization mass spectrometry. Although all the analyzed series of compounds are detected by both methods, their relative abundances are different. A number-average mass is used as a quantitative characteristic of the series. It is shown that this value is close for the distributions of the series of compounds in the mass spectrum of exhaled breath condensate and the mass spectrum obtained by summation of direct mass spectra over the breathing time.

MALDI MS imaging (MALDI-MSI) offers a capability to not only evaluate the distribution, localization and metabolism of drugs within tissues but also allow correlative tissue measurement of the effect of the drug on biomolecules in the targeted pathway. Particularly for MALDI-MSI, lipid molecules are readily detectable within tissues. Case study examples are provided for two different drugs targeting the sphingosine-1-phosphate/ceramide nexus in tumor xenograft tissues. A workflow combining high-resolution MALDI-MSI with on-tissue confirmation of targeted compounds using a structural library and on-tissue enzymatic digestion strategy is described. Representative images of drug metabolite distribution that correlate to an increase or decrease in sphingosine-1-phosphate or ceramide species are provided.

The chiral separation of haloxyfop enantiomers was first performed on (R, R) Whelk-O1 chiral column (pirkle type) by high-performance liquid chromatography (HPLC). Chromatographic conditions such as mobile phase composition and column temperature were optimized, and the best resolution was obtained using hexane/n-propanol (98/2) with Rs value of 3.43. Chiral residue analysis methods for haloxyfop enantiomers in environmental matrices, such as soil and water, were developed with recoveries ranging from 85.95% to 104.25%. The results showed that these methods were effective enough for detecting the residual enantiomers environmental matrices. The behavior of haloxyfop in four soils was studied and the enantioselective degradation was found with enantiomer fraction values ranging from 0.058 to 0.61. The research work was extremely useful for investigating the fate of individual enantiomers in environment, the mechanism of the stereoselective behaviors, and the risk assessment of chiral pesticide., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The metabolic fate of (14)C-phenyl-labeled herbicide clodinafop-propargyl ((14)C-CfP) was studied for 28 days in lab assays using a sediment-water system derived from a German location. Mineralization was 5.21% of applied (14)C after 28 days exhibiting a distinct lag phase until day 14 of incubation. Portions of radioactivity remaining in water phases decreased at moderate rate to 18.48% after 28 days; 62.46% were still detected in water after 14 days. Soxhlet extraction of the sediment using acetonitrile released 35.56% of applied (14)C with day 28, while 33.99% remained as non-extractable residues. A remarkable increase of bound (14)C was observed between 14 and 28 days correlating with the distinct increase of mineralization. No correlation was found throughout incubation with microbial activity of the sediment as determined by dimethyl sulfoxide reduction. Dissolved oxygen and pH value of water phases remained almost constant for 28 days. Analyses of Soxhlet extracts of the sediment and ethyl acetate extracts of water phases by radio-TLC and radio-HPLC revealed that CfP was rapidly cleaved to free acid clodinafop (Cf), which was further (bio-) transformed. DT50 values (based on radio-HPLC) were below 1 day (CfP) and slightly above 28 days (Cf). Further metabolites were not detected. Fractionation of humic and non-humic components of the sediment demonstrated that CfP's non-extractable residues were predominantly associated with fulvic acids up to 14 days of incubation (3.36%), whereas after 28 days, the majority of radioactivity was found in the humin/mineral fraction (13.30% of applied (14)C). Due to high-performance size-exclusion chromatography of the fulvic acids fraction derived from assays incubated for 28 days, this portion of (14)C was firmly, possibly covalently bound to fulvic acids and did not consist of CfP or Cf. Using an isolation strategy comprising preincubation of sediment with CfP and mineralization of (14)C-CfP as criterion, a microorganism was isolated from the sediment examined. It grew on (14)C-CfP as sole carbon source with evolution of (14)CO2. The bacterium was characterized by growth on commonly used carbon sources and 16S rDNA sequence analysis. Its sequence exhibited high similarity with that of Nocardioides aromaticivorans strain H-1 (98.85%; DSM 15131, JCM 11674).

1. Crizotinib (XALKORI®), an oral inhibitor of anaplastic lymphoma kinase (ALK) and mesenchymal-epithelial transition factor kinase (c-Met), is currently approved for the treatment of patients with non-small cell lung cancer that is ALK-positive. 2. The metabolism, excretion and pharmacokinetics of crizotinib were investigated following administration of a single oral dose of 250 mg/100 µCi [(14)C]crizotinib to six healthy male subjects. 3. Mean recovery of [(14)C]crizotinib-related radioactivity in excreta samples was 85% of the dose (63% in feces and 22% in urine). 4. Crizotinib and its metabolite, crizotinib lactam, were the major components circulating in plasma, accounting for 33% and 10%, respectively, of the 0-96 h plasma radioactivity. Unchanged crizotinib was the major excreted component in feces (∼ 53% of the dose). In urine, crizotinib and O-desalkyl crizotinib lactam accounted for ∼ 2% and 5% of the dose, respectively. Collectively, these data indicate that the primary clearance pathway for crizotinib in humans is oxidative metabolism/hepatic elimination. 5. Based on plasma exposure in healthy subjects following a single dose of crizotinib and in vitro potency against ALK and c-Met, the crizotinib lactam diastereomers are not anticipated to contribute significantly to in vivo activity; however, additional assessment in cancer patients is warranted.

A method based on solid phase extraction and ultra performance liquid chromatography coupled with tandem mass spectrometry (SPE-UPLC-MS/MS) has been proposed for the determination of wilforine residue in honey. After the sample was dissolved with water, concentrated and purified by an HLB solid phase extraction cartridge, the UPLC separation was performed on a Hypersil GOLD C18 column (50 mm x 2.1 mm, 1.9 microm) utilizing a gradient elution program of methanol (containing 0.15% formic acid) and water as mobile phases at a flow rate of 0. 25 mL/min. The determination was carried out with electrospray ion source in the positive mode (ESI) and multiple reaction monitoring (MRM) mode. The mass concentration of wilforine in the range of 0.01-2 microg/L was linearly correlated with the peak area, and the correlation coefficients was greater than 0.998. The limit of quantification (S/N>10) for wilforine was 0.01 microg/kg. The recoveries were 76.1% to 96.2% in the spiked levels of 0.01, 0.05 and 0.5 microg/kg with the relative standard deviations (RSD, n=6) lower than 10%. The results indicate that the method is rapid, sensitive and accurate, and can be applied for the qualitative and quantitative analysis of wilforine in honey.

A number of 100 Pu-erh tea samples from the 2013 harvest in Yunnan Province (China) were analysed for 74 pesticides. A total of 11 pesticides were detected. At least one pesticide was detected in 56% of the samples. None of these samples contained the 74 monitored pesticides at concentrations above the Chinese maximum residual levels. Imidacloprid, bifenthrin and acetamiprid were most frequently found, with percentages of 53%, 46% and 31%, respectively. These were also the top three pesticides with maximum concentrations of 140, 246 and 672 μg kg⁻¹, respectively. Residual levels of the monitored pesticides showed no significant correlation with the production time or area of Pu-erh tea. Whereas a high incidence of pesticide residues was detected in Pu-erh tea, the contamination levels observed do not pose any serious health risks.

Monitoring of plant protection product (PPP) residues in "Golden Delicious" apples was performed in 2011-2013, where 216 active substances were analysed with three analytical methods. Integrated pest management (IPM) production and improved IPM production were compared. Results were in favour of improved IPM production. Some active compounds determined in IPM production (boscalid, pyraclostrobin, thiacloprid and thiametoxam) were not found in improved IPM production. Besides that, in 2011 and 2012, captan residues were lower in improved IPM production. Risk assessment was also performed. Chronic exposure of consumers was low in general, but showed no major differences for IPM and improved IPM production for active substances determined in both types of production. Analytical results were compared with the European Union report of 2010 where 1.3% of apple samples exceeded maximum residue levels (MRLs), while MRL exceedances were not observed in this survey.

By using 5.75 and 47.5 mT nuclear magnetic resonance (NMR) spectroscopy, up to 10(5)-fold sensitivity enhancement through signal amplification by reversible exchange (SABRE) was enabled, and subsecond temporal resolution was used to monitor an exchange reaction that resulted in the buildup and decay of hyperpolarized species after parahydrogen bubbling. We demonstrated the high-resolution low-field proton magnetic resonance imaging (MRI) of pyridine in a 47.5 mT magnetic field endowed by SABRE. Molecular imaging (i.e. imaging of dilute hyperpolarized substances rather than the bulk medium) was conducted in two regimes: in situ real-time MRI of the reaction mixture (in which pyridine was hyperpolarized), and ex situ MRI (in which hyperpolarization decays) of the liquid hyperpolarized product. Low-field (milli-Tesla range, e.g. 5.75 and 47.5 mT used in this study) parahydrogen-enhanced NMR and MRI, which are free from the limitations of high-field magnetic resonance (including susceptibility-induced gradients of the static magnetic field at phase interfaces), potentially enables new imaging applications as well as differentiation of hyperpolarized chemical species on demand by exploiting spin manipulations with static and alternating magnetic fields., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

In this work, we develop a simple and rapid sensing method for the visual and fluorescent detection of acetamiprid (AC) based on the inner-filter effect (IFE) of gold nanoparticles (AuNPs) on ratiometric fluorescent quantum dots (RF-QDs). The RF-QDs based dual-emission nanosensor was fabricated by assembling green emissive QDs (QDs539nm, λem=539 nm) on the surface of red emissive QDs (QDs661nm, λem=661 nm)-doped silica microspheres. The photoluminescence (PL) intensity of RF-QDs could be quenched by AuNPs based on IFE. Acetamiprid can adsorb on the surface of AuNPs due to its cyano group that has good affinity with gold, which could induce the aggregation of AuNPs accompanying color change from red to blue. Thus, the IFE of AuNPs on RF-QDs was weakened and the PL intensity of RF-QDs was recovered accordingly. Under the optimized conditions, the PL intensity of the RF-QDs/AuNPs system was proportional to the concentration of AC in the range of 0.025-5.0 μg mL(-1), with a detection limit of 16.8 μg L(-1). The established method had been used for AC detection in environmental and agricultural samples with satisfactory results., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Two dinuclear osmium polypyridyl complexes function as convenient, easy to handle TEM contrast agents and facilitate the high-resolution visualisation of intracellular structure, particularly sub-nuclear detail.

A bi-enzyme tracer direct competitive enzyme-linked immunosorbent assay (dc-ELISA) was developed based on anti-imidaclothiz and anti-thiacloprid antibodies. Several affected physicochemical factors were optimised, including methanol concentration, ionic strength and pH value. Under the optimised conditions, 50% inhibiting concentration (IC50) values for thiacloprid and imidaclothiz were 182.62 and 58.17 μg/L, with a limit of detection (LOD) of 4.25 and 2.12 μg/L, respectively. There was no obvious cross reactivity (CR) between the two pesticides with most neonicotinoids pesticides except imidacloprid. The method analyzing the spiked samples of tomato, pear and cabbage showed satisfying recoveries (85.27-113.07%). Comparable dissipation of thiacloprid and imidaclothiz in authentic tomato samples determined with the dc-ELISA and high performance liquid chromatography (HPLC) indicated that dc-ELISA is suitable for monitoring thiacloprid and imidaclothiz residues simultaneously in agricultural samples., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Chemical evaluation of gunshot residues (GSR) produced by non-toxic lead-free ammunition (NTA) has been a challenge to forensic analyses. Our group developed some luminescent markers specific to the detection of GSR. Here, we evaluated the performance of selected markers in experiments that mimic forensic context and/or routines in which luminescent characteristics would be very useful. We evaluated the influence of markers' addition on the bullet's speed, the rate of shot failure (i.e., when the cartridge case is not fully ejected and/or a new ammunition is not automatically replaced in the gun chamber) as a function of marker percentage, the possibility of collecting luminescent gunshot residue (LGSR) in unconventional locations (e.g. the shooters' nostrils), the LGSR lifetime after hand washing, the transfer of LGSR to objects handled by the shooter, and the dispersion of LGSR at the crime scene and on simulated victims. It was observed that high amounts of marker (10 wt%) cause high rates of failure on pistols, as well as a substantial decrease in bullet speed. However, the use of 2 wt% of marker minimizes these effects and allows LGSR detection, collection and analysis. Moreover, in all conditions tested, markers showed high performance and provided important information for forensic analyses. For instance, the LGSR particles were found on the floor, ranging from 0 to 9.4 m away from the shooter, on the door panel and seats after a car shooting experiment, and were found easily on a pig leg used to simulate a victim. When a selective tagging was done, it was possible to obtain positive or negative correlation between the victim and shooter. Additionally LGSR possesses a fairly long lifetime (9 h) and good resistance to hand washing (up to 16 washes)., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Mechanical abrasion is an extremely simple, rapid, and low-cost method for deposition of carbon-based materials onto a substrate. However, the method is limited in throughput, precision, and surface compatibility for drawing conductive pathways. Selective patterning of surfaces using laser-etching can facilitate substantial improvements to address these current limitations for the abrasive deposition of carbon-based materials. This study demonstrates the successful on-demand fabrication of fully-drawn chemical sensors on a wide variety of substrates (e.g., weighing paper, polymethyl methacrylate, silicon, and adhesive tape) using single-walled carbon nanotubes (SWCNTs) as sensing materials and graphite as electrodes. Mechanical mixing of SWCNTs with solid or liquid selectors yields sensors that can detect and discriminate parts-per-million (ppm) quantities of various nitrogen-containing vapors (pyridine, aniline, triethylamine).

Modification of the Linear Solvation Energy Relationship (LSER) equation to account for ionic interactions in the retention of ionizable compounds has enabled the elucidation in the effect of the imidazolium cation identity on retention. Three Surface Confined Ionic Liquid stationary phases were synthesized from an octylbromide phase on silica: 1-octyl-3-methylimidazolium bromide (MIM), 1-octyl-3-butylimidazolium bromide (BIM), and 1-octyl-3-benzylimidazolium bromide (BzIM). These phases were probed via a 35 analyte probe set, including 6 phenolic acids, 5 anilinic bases, and 2 pyridinic bases, and the resulting column parameters compared with previously reported interactions of ionic liquids or Surface Confined Ionic Liquids. The correlation between experimental and calculated retention for the conventional, 6-parameter LSER equation was very poor: r(2)=0.64 (MIM), 0.60 (BIM), and 0.62 (BzIM). By accounting for the ionic interactions between stationary phase and analytes, linearity for the modified, 8 parameter LSER equation was significantly improved to r(2)=0.997 (MIM), 0.996 (BIM), and 0.997 (BzIM). The primary difference between cation identities is within the retention of acids where BIM>BzIM>MIM. We conjecture that the accessibility of bulky, acidic analytes to the on-top interaction of the imidazolium ring is the major contributor to increased anion retention., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The effects of Chinese spices on the profiles of 17 heterocyclic amines (HAs) from seven HA categories were investigated in roast beef patties using Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS) and principal component analysis. Three groups of HAs, imidazopyridines (PhIP, DMIP, and 1,5,6-TMIP), imidazoquinoxalines (MeIQx and 4,8-DiMeIQx), and β-carbolines (harman and norharman), were detected and quantified in all of the samples. The results demonstrated that the total HA and imidazopyridine profiles could clearly be affected by 1% pricklyash peel (14.1 ± 0.76 and 6.06 ± 0.32 ng/g), chilli (41.0 ± 0.01 and 23.0 ± 0.52 ng/g), and cumin (59.9 ± 2.44 and 31.1 ± 3.06 ng/g), in comparison with control values of 21.8 ± 2.40 and 14.3 ± 2.04 ng/g, respectively. The difference was only significant (p < 0.05) for cumin. The imidazoquinoxaline profile was significantly (p < 0.05) affected by 1% pricklyash peel (0.57 ± 0.05 ng/g) and cumin (2.36 ± 0.20 ng/g) compared to the control (1.16 ± 0.11 ng/g). The β-carboline profile was only markedly (p < 0.05) affected by 1% cumin (26.4 ± 0.82 ng/g) compared to the control (6.26 ± 0.26 ng/g). In general, pricklyash peel inhibited HA formation, whereas star anise, fennel, cumin, chilli, and black pepper promoted HA formation. The findings could facilitate the selection of spices in meat processing to minimize HA formation.

Cocaine represents a serious problem to society. Smoked cocaine is very addictive and it is frequently associated with violence and health issues. Knowledge of the purity and adulterants present in seized cocaine, as well as variations in drug characteristics are useful to identify drug source and estimate health impact. No data are available regarding smoked cocaine composition in most countries, and the smoked form is increasing in the Brazilian market. The purpose of the present study is to contribute to the current knowledge on the status of crack cocaine seized samples on the illicit market by the police of São Paulo. Thus, 404 samples obtained from street seizures conducted by the police were examined. The specimens were macroscopically characterized by color, form, odor, purity, and adulterant type, as well as smoke composition. Samples were screened for cocaine using modified Scott test and thin-layer chromatographic (TLC) technique. Analyses of purity and adulterants were performed with gas chromatography equipped with flame ionization detector (GC-FID). Additionally, smoke composition was analyzed by GC-mass spectrometry (MS), after samples burning. Samples showed different colors and forms, the majority of which is yellow (74.0%) or white (20.0%). Samples free of adulterants represented 76.3% of the total. Mean purity of the analyzed drug was 71.3%. Crack cocaine presented no correlations between macroscopic characteristics and purity. Smoke analysis showed compounds found also in the degradation of diesel and gasoline. Therefore, the drug marketed as crack cocaine in São Paulo has similar characteristics to coca paste. High purity can represent a greater risk of dependency and smoke compounds are possibly worsening drug health impact., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

The impacts of fluopyram on a soil microbial community were studied at three application rates: at the recommended field rate (T1, 0.5mg/kg soil), three-fold recommended field rate (T3, 1.5mg/kg soil) and ten-fold recommended field rate (T10, 5mg/kg soil). Soil samples were taken after 7, 15, 30, 45, 60 and 90 days of application to determine the fluopyram residue and microbial properties (i.e., basal respiration, substrate-induced respiration, microbial biomass carbon, microbial community function and structure). The half-lives of the fluopyram at levels of 0.5, 1.5 and 5mg/kg in soil were calculated to be 64.2, 81.5 and 93.6 days, respectively. The results demonstrated that fluopyram treatment (T1, T3 and T10) decreased microbial biomass C but increased the basal respiration, substrate-induced respiration, and ecophysiological indices (qCO2). Average well color development (AWCD) represents the oxidative capacity of soil microorganisms cultivated in the BIOLOG micro-plates and usually indicates the overall microbial metabolic capacity. The BIOLOG results revealed that the AWCD in the soil treated with 1.5 and 5mg/kg fluopyram (T3 and T10) was significantly lower than that of the control during the incubation period. A similar variation in the diversity indices (Simpson index and McIntosh index) was observed. Phospholipid fatty acid (PLFA) analysis revealed that the addition of fluopyram decreased the total amount of PLFAs, bacterial biomass (both Gram-positive (GP) bacteria and Gram-negative (GN)), fungal biomass, the ratios of the GN/GP and fungi/bacteria at all incubation times. Principal component analyses (PCA) suggested that the addition of fluopyram shifted the soil microbial community structure and function. Hence, fluopyram has a harmful effect on overall soil microbial activity, and changed soil microbial community structure and function., (Copyright © 2014. Published by Elsevier Inc.)

Objectives: Secondhand smoke (SHS) is a defined occupational hazard. The association though between SHS exposure in semi-open air venues and tobacco specific carcinogen uptake is an area of debate., Material and Methods: A cross sectional survey of 49 semi-open air cafes in Athens, Greece was performed during the summer of 2008, prior to the adoption of the national smoke free legislation. All venues had at least 1 entire wall open to allow for free air exchange. Indoor concentrations of particulate matter smaller than 2.5 microns (PM2.5) attributable to SHS were assessed during a work shift, while 1 non-smoking employee responsible for indoor and outdoor table service from each venue provided a post work shift urine sample for analysis of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL)., Results: Post work shift NNAL concentrations were correlated with work shift PM2.5 concentrations attributable to SHS (r = 0.376, p = 0.0076). Urinary NNAL concentrations among employees increased by 9.5%, per 10 μg/m(3) increase in PM2.5 concentrations attributable to SHS after controlling for the time of day and day of week., Conclusions: These results indicate that the commonly proposed practice of maintaining open sliding walls as a means of free air exchange does not lead to the elimination of employee exposure to tobacco specific carcinogens attributable to workplace SHS.

Ultraperformance convergence chromatography/tandem triple quadrupole mass spectrometry (UPC(2)-MS/MS) is a novel tool in separation science that combines the advantages of supercritical fluid chromatography with ultraperformance liquid chromatography/MS/MS technology. The use of nontoxic CO2 fluid and a postcolumn additive to complement MS/MS allows better control of analyte retention for chiral separation and high-sensitivity determination with different chiral stationary phases. This paper reports the stereoselective separation and determination of the chiral neonicotinoid sulfoxaflor in vegetables and soil by UPC(2)-MS/MS. Baseline resolution (Rs ≥ 1.56) of and high selectivity (LOQ ≤ 1.83 μg/kg) for the four stereoisomers were achieved by postcolumn addition of 1 % formic acid-methanol to a Chiralpak IA-3 using CO₂/isopropanol/acetonitrile as the mobile phase at 40 °C, 2,500 psi, and for 6.5 min in electrospray ionization positive mode. Rearranged Van't Hoff equations afforded the thermodynamic parameters ΔH (ο) and ΔS (ο), which were analyzed to promote understanding of the enthalpy-driven separation of sulfoxaflor stereoisomers. The interday mean recovery, intraday repeatability, and interday reproducibility varied from 72.9 to 103.7%, from 1.8 to 9.2%, and from 3.1 to 9.4%, respectively. The proposed method was used to study the pharmacokinetic dissipation of sulfoxaflor stereoisomers in soil under greenhouse conditions. The estimated half-life ranged from 5.59 to 6.03 d, and statistically nonsignificant enantioselective degradation was observed. This study not only demonstrates that the UPC(2)-MS/MS system is an efficient and sensitive method for sulfoxaflor stereoseparation, but also provides the first experimental evidence of the pharmacokinetic dissipation of sulfoxaflor stereoisomers in the environment.

A green, simple, and efficient method, ionic liquid-assisted liquid-liquid microextraction based on the solidification of floating organic droplets (ILSFOD-LLME) collected via a bell-shaped collection device (BSCD) coupled to high performance liquid chromatography with a variable-wavelength detector, was developed for the preconcentration and analysis of seven benzoylurea insecticides (BUs) in fruit juice. In the proposed method, the low-density solvent 1-dodecanol and the ionic liquid trihexyl(tetradecyl)phosphonium hexafluorophosphate ([P14, 6, 6, 6]PF6) were used as extractant. The extraction solvent droplet was easily collected and separated by the BSCD without centrifugation. The experimental parameters were optimized by the one-factor-at-a-time approach and were followed using an orthogonal array design. The results indicated the different effects of each parameter for extraction efficiency. Under the optimal conditions in the water model, the limits of detection for the analytes varied from 0.03 to 0.28μgL(-1). The enrichment factors ranged from 160 to 246. Linearities were achieved for hexaflumuron and flufenoxuron in the range of 0.5-500μgL(-1), for triflumuron, lufenuron and diafenthiuron in the range of 1-500μgL(-1), and for diflubenzuron and chlorfluazuron in the range of 5-500μgL(-1); the correlation coefficients for the BUs ranged from 0.9960 to 0.9990 with recoveries of 75.6-113.9%. Finally, the developed technique was successfully applied to real fruit juice with acceptable results. The relative standard deviations (RSDs) of the seven BUs at two spiked levels (50 and 200μgL(-1)) varied between 0.1% and 7.3%., (Copyright © 2014 Elsevier B.V. All rights reserved.)

This paper represents the first report of a capillary electrophoresis (CE) method compatible with mass spectrometry (MS) detection for simultaneously analyzing seven neonicotinoid insecticides (acetamiprid, clothianidin, dinotefuran, imidacloprid, nitenpyram, thiacloprid and thiamethoxam). Different variables affecting CE separation (buffer concentration, pH, applied voltage and injection time) and MS detection (electrospray parameters) were studied. Low limits of detection (LOD) and quantification (LOQ) were achieved for all analytes, ranging from 1.0 to 2.3μg/L, and from 3.5 to 7.2μg/L, respectively. In addition, the proposed method showed itself to be linear in the range from LOQ to 1000μg/L and to be precise, as the relative standard deviations of the migration times were lower than 4% in all cases. Finally, the proposed CE-MS method was applied to assess the efficacy of a beeswax cleaning treatment with oxalic acid to remove residues of three of the most commonly used neonicotinoids (clothianidin, imidacloprid and thiamethoxam), use of which has recently been restricted by the European Union., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The 4'-(2-fluorenyl)-2,2':6',2''-terpyridine (FT) ligand and its cis(Cl,Cl)- and trans(Cl,Cl)-[Ru(II)(FT)Cl2(NO)](PF6) complexes have been synthesized. Both isomers were separated by HPLC and fully characterized by (1)H and (13)C NMR. The X-ray diffraction crystal structures were solved for FT (Pna21 space group, a = 34.960(4), b = 5.9306(7), c = 9.5911(10) Å), and trans(Cl,Cl)-[Ru(II)(FT)Cl2(NO)](PF6)·MeOH (P1[combining macron] space group, a = 10.3340(5), b = 13.0961(6), c = 13.2279(6) Å, α = 72.680(2), β = 70.488(2), γ = 67.090(2)°). Photo-release of NO˙ radicals occurs under irradiation at 405 nm, with a quantum yield of 0.31 and 0.10 for cis(Cl,Cl)-[Ru(II)(FT)Cl2(NO)](PF6) and trans(Cl,Cl)-[Ru(II)(FT)Cl2(NO)](PF6), respectively. This significant difference is likely due to the trans effect of Cl(-), which favors the photo-release. UV-visible spectroscopy and cyclic voltammetry indicate the formation of ruthenium(iii) species as photoproducts. A density functional theory (DFT) analysis provides a rationale for the understanding of the photo-physical properties, and allows relating the weakening of the Ru-NO bond, and finally the photo-dissociation, to HOMO → LUMO excitations.

Degraded landscapes, like those from abandoned mine areas, could be restored by revegetating them with appropriate plant species, after correction for acidity and improvement by adding exogenous organic material. Application of urban wastes to large areas of derelict land helps in the sustainable development of this landscape. However, the development of plant species in these soils could require in the future the management of possible pests or diseases by pesticide applications which could also affect plant yield. Therefore, ryegrass (Lolium perenne L.) was planted in a limed soil from the mining area of Riotinto (SW Spain), using an indoor pot experiment and the effects of amendment with sewage sludge, as well as irrigation with urban wastewater on plant uptake of the insecticide thiacloprid and the fungicide fenarimol were examined. Ryegrass biomass was reduced up to 3-fold by pesticide application. Fenarimol residues were the highest in soil, while those of thiacloprid were lower in soil and higher in ryegrass. Addition of sewage sludge and irrigation with wastewater led to a reduction of pesticide translocation to the aerial plant parts, representing a lower hazard to ryegrass quality grown in this mine soil., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Methods have been developed for the determination of zinc pyrithione (ZPT) in shampoos using high-performance liquid chromatography (HPLC) and high-performance liquid chromatography-mass spectrometry/mass spectrometry (HPLC-MS/MS). Samples were washed by water first to remove surfactant and water-soluble impurities, then ultrasonic-extracted by acetonitrile-methanol for 30 min, and finally analyzed by MG C18 column (250 mm x 4.6 mm, 5 μm) or RP-18e (100 mm x 3 mm, 2 μm) plus APCI-MS/MS. Limits of detection were determined as 0.015% (HPLC) and 0.003% (HPLC-MS/MS), with a limit of quantization of 0.05% and 0.01%, respectively. The recoveries were 85.8-104% (HPLC) and 87.6-107% (HPLC-MS/MS). A good linear relationship was obtained from 3.20 μg·ml(-1) to 200 μg·ml(-1) (HPLC) and 1.00 μg·ml(-1) to 200 μg·ml(-1) (HPLC-MS/MS). The proposed methods have been successfully applied to the analysis of ZPT in many shampoos. The established two methods were rapid and reproducible with low interference.

Degradation of acetamiprid in wastewater was studied in a dielectric barrier discharge (DBD) reactor. This reactor produces ultraviolet light and reactive species like ozone (O₃) can be used for the treatment of wastewater. We examined the factors that could affect the degradation process, including the discharge power, and the initial concentrations of acetamiprid, and O₃ which is generated by the DBD reactor. We also investigated the effect of adding Na₂B₄O₇ as a radical scavenger to probe the role of hydroxyl radical in the reaction. The results indicated that acetamiprid could be removed from aqueous solution effectively and hydroxyl radicals played an important role during the degradation by the low temperature plasma. The degradation process of acetamiprid fits the first-order kinetics. The degradation efficiency was 83.48 percent at 200 min when the discharge power was 170 W and the initial acetamiprid concentration was 50 mg/L. The removal efficiency of acetamiprid decreased with the increasing concentration of Na₂B₄O₇ because B₄O₇(2-) is an excellent radical scavenger that inhibited the generation of OH during the DBD process. The removal efficiency of acetamiprid improved in the presence of O₃. The main reason was that O₃ can oxidize certain organic compounds directly or indirectly by generating hydroxyl radicals. The degradation products of acetamiprid were characterized qualitatively and quantitatively using high performance liquid chromatography, mass spectrometry and UV-vis spectroscopy., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Background: Thiacloprid is a chloronicotinyl insecticide that is quite effective against sucking insects. In this study, when thiacloprid was applied at two different rates (normal rate 15 kg ha(-1) , double rate 30 kg ha(-1) ), the systemic distribution and residue of thiacloprid as well as its control effect against whitefly (Bemisia tabaci) were investigated in greenhouse tomato after soil application., Results: The results showed that thiacloprid was present in the tomato leaves until day 25, and then its amount was less than 0.005 mg kg(-1) and could not be detected. Thiacloprid residue in the tomato stems basically remained at a stable low level throughout the experimental period. Thiacloprid in soil had half-lives of 11.8 and 12.5 days for the normal treatment and the double treatment respectively. The control efficiency of whiteflies was about 90% from day 1 to day 10. This was followed by a slow decline, but efficiency was still higher than 50% until day 21. In addition, no significant differences were noted in the control effect of thiacloprid on whiteflies between the two different rates., Conclusion: Soil application of thiacloprid at the normal rate can effectively control whiteflies, with high efficiency and long persistence., (© 2013 Society of Chemical Industry.)

In order to solve the shortage of natural Tripterygium wilfordii Hook. f. plant resource for the production of the important secondary metabolites triptolide and wilforine, hairy roots were induced from its root calli by Agrobacterium rhizogenes. Induced hairy roots not only could be maintained and grown well in hormone-free half-strength Murashige and Skoog medium but also could produce sufficient amounts of both triptolide and wilforine. Although hairy roots produced approximately 15% less triptolide than adventitious roots and 10% less wilforine than naturally grown roots, they could grow fast and could be a suitable system for producing both secondary metabolites compared with other tissues. Addition of 50 micrometer methyl jasmonate (MeJA) could slightly affect hairy root growth, but dramatically stimulated the production of both triptolide and wilforine, whereas 50 micrometer salicylic acid had no apparent effect on hairy root growth with slightly stimulatory effects on the production of both secondary metabolites. Addition of precursor nicotinic acid, isoleucine, or aspartic acid at the concentration of 500 micrometer had varying effects on hairy root growth, but none of them had stimulatory effects on triptolide production, and only the former two had slightly beneficial effects on wilforine production. The majority of triptolide produced was secreted into the medium, whereas most of the produced wilforine was retained inside of hairy roots. Our studies provide a promising way to produce triptolide and wilforine in T. wilfordii hairy root cultures combined with MeJA treatment.

A novel 3D-graphene (3D-G) magnetic nanomaterial was prepared and used as an adsorbent for the extraction of four neonicotinoid insecticides (acetamiprid, imidacloprid, thiacloprid, and thiamethoxam) from lemon juice sample. Then, HPLC with UV detection was applied for the determination of the neonicotinoid insecticides desorbed from the 3D-G magnetic nanomaterial. The main experimental parameters that affect the extraction efficiencies such as the amount of 3D-G magnetic nanomaterial, sample solution pH, extraction time, salting-out effect, and desorption conditions were studied and optimized. As a result, the linear concentration range of the method was from 0.3 to 100.0 ng/mL for thiacloprid, from 0.5 to 100.0 ng/mL for imidacloprid and acetamiprid, and from 1.0 to 100.0 ng/mL for thiamethoxam, with correlation coefficients of 0.9965-0.9985, respectively. The LODs of the method based on an S/N of 3 were between 0.08 and 0.2 ng/mL. The enrichment factors obtained were between 67 and 427, and the RSDs (n = 6) were in the range from 4.6 to 7.1%, and the recoveries of the method fell in the range of 88.75 to 111.60%., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The adventitious root of Tripterygium wilfordii was used as experiment material to study effects of various concentration of aspartic acid, isoleucine, cysteine and arginine in MS medium on the growth and triptolide, wilforgine, wilforine contents of the adventitious roots. The results showed that compared with the control, supplemented with 0.25 mmol x L(-1) aspartic acid at 3rd week, the growth of the adventitious roots only accounted for 80%, but the content of triptolide of the adventitious roots and the medium was 1.36, 1.30 times, the content of wilforgine was 1.16, 1.37 times, the content of wilforine was 1.22, 1.63 times, respectively. At 3rd week 0.05 mmol x L(-1) isoleucine, the growth of adventitious roots was 97.3%, wilforgine of adventitious roots and medium 1.02, 1.27 times, wilforine 1.36 times and 1.15 times. At 1st week 0.25 mmol x L(-1) cysteine, the growth of the adventitious roots comprised 77.5% of the control, while content of triptolide of adventitious roots reached 1.87 times. At 2nd week 1.00 mmol x L(-1) cysteine, the growth of adventitious roots was 44.6% of the control, the content of wilforine in medium was 2.97 times. At 3rd week 0.50 mmol x L(-1) arginine, the growth of adventitious roots was 124.2%, the content of wilforgine and wilforine was 1.3, 1.4 times, respectively.

This paper describes a Bayesian model for the assessment of inhalation exposures in an occupational setting; the methodology underpins a freely available web-based application for exposure assessment, the Advanced REACH Tool (ART). The ART is a higher tier exposure tool that combines disparate sources of information within a Bayesian statistical framework. The information is obtained from expert knowledge expressed in a calibrated mechanistic model of exposure assessment, data on inter- and intra-individual variability in exposures from the literature, and context-specific exposure measurements. The ART provides central estimates and credible intervals for different percentiles of the exposure distribution, for full-shift and long-term average exposures. The ART can produce exposure estimates in the absence of measurements, but the precision of the estimates improves as more data become available. The methodology presented in this paper is able to utilize partially analogous data, a novel approach designed to make efficient use of a sparsely populated measurement database although some additional research is still required before practical implementation. The methodology is demonstrated using two worked examples: an exposure to copper pyrithione in the spraying of antifouling paints and an exposure to ethyl acetate in shoe repair., (© Crown copyright 2014.)

An ultrasensitive assay utilizing high-pressure liquid chromatography and mass spectrometry detection was developed and validated for the quantification of the antiretrovirals atazanavir (ATV), darunavir (DRV), lopinavir (LPV), ritonavir (RTV), and efavirenz (EFV) in human mononuclear cell (MNC) extracts. The assay utilizes 20 μl of cellular extract that contains as few as 50,000 MNCs. The analytical range of the assay is 0.0200 to 10.0 fmol/μl for ATV, 0.0500 to 25.0 fmol/μl for DRV, LPV, and RTV, and 0.200 to 100 fmol/μl for EFV. The assay has proven to be a clinically useful tool for investigating antiretroviral drug concentrations in virologic sanctuaries where harvested cell numbers are extremely low. The assay provides a tool for investigators to explore the clinical pharmacology of strategies for prevention, treatment, and cure in pathophysiologically relevant sites.

Forchlorfenuron, N-(2-chloro-4-pyridinyl)-N'-phenylurea, is a plant growth regulator used to increase the size of kiwifruit, apples, table grapes, and peaches and to promote increased yields of potatoes, rice, and wheat. This study reports the comparison of the performances of two extraction methods [Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) and SPE] and two analytical methods (LC-UV and a LC/MS/MS) when determining forchlorfenuron in apples, kiwis, and grapes. Both extraction methods gave recoveries of forchlorfenuron from fruits >70%. The QuEChERS method was cheaper, safer, and less time-consuming than the SPE method and can be recommended for routine analysis. The LOQ was 2 and 10 microg/kg for the LC/MS/MS and LC-UV analysis, respectively. The LOD was 1 and 5 microg/kg for the LC/MS/MS and LC-UV analysis, respectively. The sensitivity of the LC-UV analysis was adequate to measure residue levels five times lower than the maximum residue limit (MRL) of the product. The QuEChERS and SPE methods were applied to monitoring the persistence of forchlorfenuron in field-treated kiwis, and it was found that the residual concentration was already much lower than the MRL 7 days after treatment.

Nine important 1,4-benzodiazepines and zolpidem were characterized by liquid chromatography-mass spectrometry using a multimode ionization source able to generate ions using both electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI), and a single quadrupole mass analyzer. An optimum chromatographic separation was applied for all target compounds in less than 8 minutes using a Zorbax Eclipse Plus column (100 × 4.6 mm, 3.5 µm) kept at 35°C and a 0.3% HCOOH/ACN/IPA (61:34:5) mobile phase pumped at 1 ml/min. Optimization of LC-MS method generated low limit of quantitation (LOQ) values situated in the range 0.3-20.5 ng/ml. Comparison between differences in method sensitivity, under specified chromatographic conditions, when using ESI-only, APCI-only, and simultaneous ESI-APCI ionization with such a multimode source was discussed. Mixed ESI-APCI(+) mode proved to be the most sensitive ionization generating an average 35% detector response increase compared to ESI-only ionization and 350% detector response increase with respect to APCI-only ionization. Characterization of the nine benzodiazepines and zolpidem concerning their MS fragmentation pathway following 'in-source' collision-induced dissociation is discussed in detail and some general trends regarding these fragmentations are set., (Copyright © 2013 John Wiley & Sons, Ltd.)

The design, preparation and performance for novel UV-light absorbing (room-temperature) ionic liquid matrices (UV-RTILMs) for matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) were reported. A series of UV-RTILMs was prepared by ultrasonication of equimolar of acid (mefenamic acid) and bases (aniline (ANI), pyridine (Pyr), dimethyl aniline (DMANI) and 2-methyl picoline (2-P)). The UV-RTILMs have not only significant absorbance at the desired wavelength (337 nm of the N2 Laser), but also have available protons that can easily undergo proton transfer reactions to ionize the target molecules. The novel UV-RTILMs have the ability to ionize different and wide classes of compounds such as drugs, carbohydrate, and amino acids. The new UV-RTILMs series have been successfully and selectively applied for biosensing the lysates of pathogenic bacteria in the presence of the cell macromolecules. A new strategy for biosensing pathogens was presented via sensing the pathogens lysate in the cell suspension. The new materials can effectively detect the bacterial toxins without separation or any pretreatment. They offered excellent ionization of labile oligosaccharides with protonated peaks. They could significantly enhance the analyte signals, produce homogeneous spotting, reducing spot-to-spot variation, excellent vacuum stability, higher ion peak intensity, and wide application possibility. The physical parameters such as molar refractivity, molar volume, parachor, surface tension, density and polarizability were calculated and tabulated. The new UV-RTILMs could offer excellent reproducibility and great repeatability and they are promising matrices for wide applications on MALDI-MS., (Copyright © 2014. Published by Elsevier B.V.)

In-package nonthermal plasma (NTP) technology is a novel technology for the decontamination of foods and biological materials. This study presents the first report on the potential of the technology for the degradation of pesticide residues on fresh produce. A cocktail of pesticides, namely azoxystrobin, cyprodinil, fludioxonil and pyriproxyfen was tested on strawberries. The concentrations of these pesticides were monitored in priori and post-plasma treatment using GC-MS/MS. An applied voltage and time dependent degradation of the pesticides was observed for treatment voltages of 60, 70 and 80 kV and treatment durations ranging from 1 to 5 min, followed by 24h in-pack storage. The electrical characterisation revealed the operation of the discharge in a stable filamentary regime. The discharge was found to generate reactive oxygen and excited nitrogen species as observed by optical emission spectroscopy., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The residues of four insecticides belonging to different families were studied on head lettuce (Lactuca sativa L. var. capitata L.), cabbage (Brassica oleracea Linn. var. capitata DC.), Chinese cabbage (Brassica pekinensis Skeels), and broccoli (Brassica oleracea var. italica) after pesticide application. To reduce application variability, a tank mix of acetamiprid 20% SP, chlorpyrifos 22.5% EC, deltamethrin 2.4% SC, and methomyl 40% SP was applied at recommended and double doses. Initial deposits of all pesticides on head lettuce were higher than those of the other three crops. The residues of chlorpyrifos and deltamethrin were higher than the maximum residue limits (MRLs) at recommended preharvest intervals (PHIs) on head lettuce and Chinese broccoli treated with higher doses. The residues of methomyl on head lettuce also showed the same phenomenon.

The simultaneous determination of four strobilurin fungicides (picoxystrobin, kresoxim-methyl, trifloxystrobin, and azoxystrobin) in cotton seed by combining acetonitrile extraction and dispersive liquid-liquid microextraction was developed prior to GC with electron capture detection. Several factors, including the type and volume of the extraction and dispersive solvents, extraction condition and time, and salt addition, were optimized. The analytes were extracted with acetonitrile from cotton seed and the clean-up was carried out by primary secondary amine. Afterwards, 60 μL of n-hexane/toluene (1:1, v/v) with a lower density than water was mixed with 1 mL of the acetonitrile extract, then the mixture was injected into 7 mL of distilled water. A 0.1 mL pipette was used to collect a few microliters of n-hexane/toluene from the top of the aqueous solution. The enrichment factors of the analytes ranged from 36 to 67. The LODs were in the range of 0.1 × 10(-3) -2 × 10(-3) mg/kg. The relative recoveries varied from 87.7 to 95.2% with RSDs of 4.1-8.5% for the four fungicides. The good performance of the method, compared with the conventional pretreatments, has demonstrated it is suitable for determining low concentrations of strobilurin fungicide residues in cotton seed., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)