Residue Behavior and Risk Assessment of Rimsulfuron and Quizalofop-P-ethyl in Potato Under Field Conditions.

A method for simultaneous quantitation of rimsulfuron, quizalofop-P-ethyl and quizalofop-P in potato plant, soil and potato tuber samples was established. The mean recoveries of rimsulfuron, quizalofop-P-ethyl and quizalofop-P in different matrices spiked with them were 81.4%-101.1%, 76.1%-99.0% and 77.4%-106.4% with relative standard deviations (RSDs) of 2.7%-13.3%, 0.9%-5.5%, 1.7%-11.3%, respectively. The open-field trials in China were conducted in potato cultivation system of Changchun and Jinan. The results indicated that the half-lives of rimsulfuron and quizalofop-P-ethyl were 0.04-13.1 days. The residues of quizalofop-P during the harvest time in Jinan soil were < 0.01-0.044 mg kg-1, while there was no residue of target herbicides detected in all other samples. The risk assessment results demonstrated that the risk quotients (RQs) of rimsulfuron and quizalofop-P-ethyl were 7.857 × 10-5 and 8.730 × 10-3, respectively, which exhibited an acceptable dietary risk to Chinese consumers.

Quantitative Determination and Validation of Four Ketones in Salvia miltiorrhiza Bunge Using Quantitative Proton Nuclear Magnetic Resonance Spectroscopy.

Salvia mltiorrhiza Bunge (SMB) is native to China, whose dried root has been used as medicine. A few chromatographic- or spectrometric-based methods have already been used to analyze the lipid-soluble components in SMB. However, the methodology of qNMR on the extracts of fresh SMB root has not been verified so far. The purpose of this study was to establish a fast and simple method to quantify the tanshinone I, tanshinone IIA, dihydrotanshinone, and cryptotanshinone in fresh Salvia Miltiorrhiza Bunge root without any pre-purification steps using 1H-NMR spectroscopy. The process is as follows: first, 70% methanol aqueous extracts of fresh Salvia Miltiorrhiza Bunge roots were quantitatively analyzed for tanshinone I, tanshinone IIA, dihydrotanshinone, and cryptotanshinone using 1H-NMR spectroscopy. Different internal standards were tested and the validated method was compared with HPLC. 3,4,5-trichloropyridine was chosen as the internal standard. Twelve samples of Salvia Miltiorrhiza Bunge were quantitatively analyzed by qNMR and HPLC respectively. Then, the results were analyzed by chemometric approaches. This NMR method offers a fast, stable, and accurate analysis of four ketones: tanshinone I, tanshinone IIA, dihydrotanshinone, and cryptotanshinone in fresh roots of Salvia Miltiorrhiza Bunge.

A LC-MS/MS method for therapeutic drug monitoring of sorafenib, regorafenib and their active metabolites in patients with hepatocellular carcinoma.

A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous quantification of sorafenib (SORA), its N-oxide active metabolite and of regorafenib (REGO) and its two active metabolites regorafenib N-oxide and N-desmethyl regorafenib N-oxide in hepatocellular carcinoma patients' plasma. A proper analytes' separation was obtained with Synergi Fusion RP column (4 µm, 80 Å, 50 × 2.0 mm) using a gradient elution of 10 mM ammonium acetate with 0.1% formic acid (mobile phase A) and methanol:isopropanol (90:10, v/v, mobile phase B) containing 0.1% formic acid. The analysis was then performed by electrospray ionization in negative mode coupled with a triple quadrupole mass spectrometry, API 4000QT, monitoring two transitions for each analyte, one for the quantification and the other for confirmation. The method could be easily applied to the clinical practice thanks to the short run (7 min), the low amount of patient plasma necessary for the analysis (5 µL) and the fast sample processing based on protein precipitation. The method was therefore fully validated according to FDA and EMA guidelines. The linearity was assessed (R2≥0.998) over the concentration ranges of 50-8000 ng/mL for SORA and REGO, and 30-4000 ng/mL for their metabolites, that appropriately cover the therapeutic plasma concentrations. The presented method also showed adequate results in terms of intra- and inter-day accuracy and precision (CV ≤ 7.2% and accuracy between 89.4% and 108.8%), recovery (≥85.5%), sensitivity, analytes stability under various conditions and the absence of the matrix effect. Once the validation was successfully completed, the method was applied to perform the Cmin quantification of SORA, REGO and their metabolites in 54 plasma samples collected from patients enrolled in a clinical study ongoing at the National Cancer Institute of Aviano.

Zwitterionic HILIC tandem mass spectrometry with isotope dilution for rapid, sensitive and robust quantification of pyridine nucleotides in biological extracts.

The pyridine nucleotides nicotineamide adenine dinucleotide (NAD) and nicotineamide adenine dinucleotide phosphate (NADP) are conserved coenzymes across all domains of life, and are involved in more than 200 different hydride transfer reactions supporting essential catabolic and anabolic functions. The intracellular levels of these metabolites, and the ratio of their oxidized to reduced forms regulate an extensive network of reactions ranging beyond metabolism. Hence, monitoring their intracellular levels provides information about, but not limited to, the metabolic state of a cell or tissue. Interconversion between oxidized and reduced forms, varying pH liability and varying intracellular concentrations of the different species leaves absolute quantification of the pyridine nucleotides analytically challenging. These polar metabolites are poorly retained on conventional reverseed-phase stationary phases without ion-pair reagents that contaminates the LC-system. Herein we demonstrate that zwitterionic HILIC-tandem mass spectroemtry can be applied to successfully resolve the pyridine nucleotides in biological extracts in a fast, robust and highly sensitive way. The presented method applies isotope dilution to compensate potential loss of these labile metabolites and is validated for low, medium and high biomass samples of two popular biological model systems; Escherichia coli and the human cell line JJN-3. High stability and rapid sample preparation without solvent removal allows for long sequence runs, making this method ideal for high-throughput analysis of biological extracts.

Comparative UHPLC-HRMS Profiling, Toxicological Assessment, and Protection Against H2O2-Induced Genotoxicity of Different Parts of Opuntia ficus indica.

Opuntia ficus indica has been an important dietary source and a traditionally used medicinal plant. Given the promising health-promoting properties of this plant, a comparative toxicological assessment and antioxidant bioevaluation of extracts from different parts of the plant were carried out in relation to their chemical profile. Toxicity was examined at multiple endpoints using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), Comet and the γH2AX In-Cell Western Assay, while hyphenated ultra-high-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS) analysis was carried out to identify main constituents. None of the extracts showed any cytotoxic and genotoxic effect on cell lines used, apart from the flower extract in HepG2 cells at the highest concentration tested (2.5 mg/mL). Both fruit flesh and seed extracts demonstrated a prominent protective effect against H2O2-induced genotoxicity in almost all concentrations tested, while extracts originated from flowers and cladodes were effective only at the low non-cytotoxic (0.312 and 0.625 mg/mL) and high (1.25 and 2.5 mg/mL) concentrations, respectively. In total, 2 phenolic acids, 12 flavonoids, along with 3 feruloyl derivatives and the plant pigment indicaxanthin, were tentatively identified by UHPLC-HRMS analysis. Phenolic acids (compounds 1 and 2) were mainly distributed in cladodes (64.6%), while flavonoids (3-14) in the flowers (81.8%). Overall, the highest amount of total flavonoids (22.76 ± 0.015 mg of quercetin equivalent [QE]/g) and total phenolics (62.80 ± 0.009 mg gallic acid equivalents [GAE]/g) was found in the flower extract. Flavonoid glycosides have not been detected in the seeds and the flesh, while the fruit seed extract contained mainly feruloyl derivatives. Our data provide convincing evidences for the lack of cytotoxic and genotoxic effects of O. ficus indica aqueous extracts and, in parallel, support the potential for further exploitation of this plant in the food supplement or functional food sector.

Development of complementary CE-MS methods for speciation analysis of pyrithione-based antifouling agents.

In the recent decade, metal pyrithione complexes have become important biocides for antifouling purposes in shipping. The analysis of metal pyrithione complexes and their degradation products/species in environmental samples is challenging because they exhibit fast UV degradation, transmetalation, and ligand substitution and are known to be prone to spontaneous species transformation within a chromatographic system. The environmental properties of the pyrithione species, e.g., toxicity to target and non-target organisms, are differing strongly, and it is therefore inevitable to identify as well as quantify all species separately. To cope with the separation of metal pyrithione species with minimum species transformation during analysis, a capillary electrophoresis (CE)-based method was developed. The hyphenation of CE with selective electrospray ionization- and inductively coupled plasma-mass spectrometry (ESI-, ICP-MS) provided complementary molecular and elemental information for the identification and quantification of pyrithione species. To study speciation of pyrithiones, a leaching experiment of several commercial antifouling paints containing zinc pyrithione in ultrapure and river water was conducted. Only the two species pyrithione (HPT) and dipyrithione ((PT)2) were found in the leaching media, in concentrations between 0.086 and 2.4 µM (HPT) and between 0.062 and 0.59 µM ((PT)2), depending on the paint and leaching medium. The limits of detection were 20 nM (HPT) and 10 nM ((PT)2). The results show that complementary CE-MS is a suitable tool for mechanistical studies concerning species transformation (e.g., degradation) and the identification of target species of metal pyrithione complexes in real surface water matrices, laying the ground for future environmental studies. Graphical abstract Hyphenation of CE with ESI- and ICP-MS provided complementary molecular and elemental information. Metal pyrithione species released from commercial antifouling paints could be identified and quantified in ultrapure and river water matrices.

Magnetic solid-phase extraction of benzoylurea insecticides in tea samples with Fe3 O4 -hyperbranched polyester magnetic composite as sorbent.

In this work, a method for the analysis of benzoylurea insecticides, including hexaflumuron, flufenoxuron, lufenuron and chlorfluazuron, in tea samples by high-performance liquid chromatography with Fe3 O4 -hyperbranched polyester nanocomposite as the adsorbent for magnetic solid-phase extraction was developed. The magnetic nanocomposite was prepared and characterized by infrared spectroscopy, vibrating sample magnetometry, and scanning electron microscopy. The as-prepared nanocomposite was used as a sorbent for the extraction and preconcentration of pesticide residues in tea samples. The extraction and desorption conditions, including mass ratios of raw materials, amount of sorbent, pH value, extraction time, and desorption time, were investigated. Under the final conditions chosen for the analysis, good linearity was obtained for all the tested compounds, with R2 values of at least 0.9979. The limits of detection were determined in the range of 0.15-0.3 µg/L. The recovery obtained from the analysis of tea samples with various spiked concentrations was between 90.7 and 98.4%, with relative standard deviations (n = 4) lower than 4.1%. Furthermore, the present approach was successfully applied to the quantitative determination of residues of benzoylurea insecticides in real samples.

Diagnostic and therapeutic approach in adult patients with traumatic brain injury receiving oral anticoagulant therapy: an Austrian interdisciplinary consensus statement.

There is a high degree of uncertainty regarding optimum care of patients with potential or known intake of oral anticoagulants and traumatic brain injury (TBI). Anticoagulation therapy aggravates the risk of intracerebral hemorrhage but, on the other hand, patients take anticoagulants because of an underlying prothrombotic risk, and this could be increased following trauma. Treatment decisions must be taken with due consideration of both these risks. An interdisciplinary group of Austrian experts was convened to develop recommendations for best clinical practice. The aim was to provide pragmatic, clear, and easy-to-follow clinical guidance for coagulation management in adult patients with TBI and potential or known intake of platelet inhibitors, vitamin K antagonists, or non-vitamin K antagonist oral anticoagulants. Diagnosis, coagulation testing, and reversal of anticoagulation were considered as key steps upon presentation. Post-trauma management (prophylaxis for thromboembolism and resumption of long-term anticoagulation therapy) was also explored. The lack of robust evidence on which to base treatment recommendations highlights the need for randomized controlled trials in this setting.

Wilforine, the Q-marker and PK-maker of Tripterygium glycosides tablet: Based on preparation quantitative analysis and PK-PD study.

BACKGROUND: The quality standard of Tripterygium glycosides tablet (TGT) by CFDA can not fully reflect the effectiveness and safety. While, Q-marker was proposed to solve the problem of traditional Chinese medicine. PK-marker is mainly used to reflect the material exposure and the influencing factors of Chinese medicine after administration. PURPOSE: Based on the study of quantitative analysis, cytotoxicity and pharmacokinetics, this study screened out and confirmed whether wilforine could be served as a potential Q-marker and PK-marker of TGT. METHODS: A sensitive and selective UPLC-MS/MS method was developed and applied to quantitative research of TGT preparation and pharmacokinetics study of TGT. Then, HepG2 cells assay was used to evaluate the cytotoxicity induced by alkaloids in TGT. Then, a PK-PD research was carried out in adjuvant arthritis (AA) rats and control rats after oral administration of TGT, with different dosage and timing. The pharmacokinetic characteristics were determined and calculated by DAS1.0. The pharmacodynamics of TGT was evaluated by the change of paw swelling through one-way ANOVA analysis. RESULTS: The quality of four alkaloids showed significant difference among four manufacturers, and they were abundant component in TGT from three manufacturers of all. HepG2 cells test revealed that wilforine and wilforgine could induce the cytotoxicity obviously. Pharmacodynamics index suggested that TGT had therapeutic effect on adjuvant arthritis. Thus, the four cases of death occurred in the high dose AA rat group had proven the significant toxicity caused by continuous high dose TGT administration. Furthermore, the result of pharmacokinetic study proved that Cmax, and AUC(0-tn) of wilforine have dose-dependent and time-dependent characteristics. But for wilforgine, there was no indication that there was an accumulation phenomenon in vivo and its plasma concentration showed low exposure. Therefore, it could hardly become the PK-marker of TGT. CONCLUSION: Wilforine is proposed as a biologically active and toxic component of TGT that can be served both as Q-marker and PK-marker. The quality, clinical safety, and efficacy of TGT should be evaluated by the quality of wilforine.

Persistence of thiacloprid and deltamethrin residues in tea grown at different locations of North-East India.

In order to examine the residues of thiacloprid (90 and 180 g a.i./ha) and deltamethrin (10 and 20 g a.i./ha) in fresh tea leaves, made tea and tea infusion, field experiments were conducted at three different locations viz. Kamalpur tea estate, Darjeeling; West Bengal, Teok tea Estate and AAU, Jorhat; Assam in India. Regardless of location and doses, residues of both the insecticides dissipated following first order kinetics. The half-life of Thiacloprid (4.93-5.38 days) was longer than that of deltamethrin (1.78-1.94 days). Processing of green tea leaves reduced the residue level of thiacloprid and deltamethrin in made tea. No residues of both these insecticides could be detected in tea infusion. With respect to the phenolic distribution in tea, a marked increase in total catechin monomers with thiacloprid and greater accumulation of EGCG and ECG (indices of phenol quality) with deltamethrin were observed.

Residue decline and risk assessment of fluopyram + tebuconazole (400SC) in/on onion (Allium cepa).

A method was validated for estimating fluopyram and tebuconazole in onion on LC-MS/MS using dispersive QuEChERS. Three sprays of a combination fungicide fluopyram + tebuconazole (Luna experience, 400 SC) were applied @ 75 + 75 and 150 + 150 g a.i. ha-1 at an interval of 10 days on onion using Knapsack sprayer. First spray was made at bulb setting stage. Spring onion samples were drawn at 0 (1 h), 1, 3, 5, 7, 10, 15, and 20 days and matured onion bulb at harvest (52 days) after the last spray. Soil samples were also drawn at harvest. Foliar application of the combination product resulted in 1.14 and 2.86 mg kg-1 fluopyram residues on spring onion at standard and double dose, respectively, one hour after the last application. The levels of fluopyram residues gradually declined and recorded 0.25 and 0.58 mg kg-1 on 20th day of application with half-lives of 8.8 and 9.1 days at standard and double dose, respectively. For tebuconazole, the corresponding residues observed after 1 h (0 day) of application were 0.92 and 2.29 mg kg-1. The levels declined gradually to 0.12 and 0.33 mg kg-1 on 20th days with half-life of 6.7 to 7.7 days at standard and double dose, respectively. Here, we are proposing a pre-harvest interval of 7 day for fluopyram and tebuconazole in spring onion when applied at 75 + 75 g a.i. ha-1 (400 SC). Risk assessment was done by calculating hazard quotient and by comparing theoretical maximum residue intake (TMRI) with maximum permissible intake (MPI). In all the cases, results of the study showed that HQ (Hazard Quotient) ≤1 and TMDI < MPI. Hence, the use of this combination product can be recommended with pre harvest interval of 7 days. The data can be used in establishing MRLs (maximum residue limits) for spring onion after considering multilocation trials.

Microclimatic variation in UV perception and related disparity in tropane and quinolizidine alkaloid composition of Atropa acuminata, Lupinus polyphyllus and Hyoscyamus niger.

The aim of current research was to evaluate the physiological adjustment in three medicinal herbs viz., Atropa acuminata, Lupinus polyphyllus and Hyoscyamus niger to the winter period characterised by intense UV flux in Kashmir valley across the North Western Himalaya. Quinolizidine (QA) and tropane alkaloid (TA) concentrations were analysed in these herbs thriving at two different altitudes via GC-MS and correlated by PCA analysis. This study investigated the hypothesis that UV reflectance and absorbance at low temperatures are directly related to disparity in alkaloid accumulation. Among QAs in L. polyphyllus, ammodendrine and lupanine accumulated at higher concentration and exhibited significant variation of 186.36% and 95.91% in ammodendrine and lupanine respectively in both sites. Tetrahydrohombifoline displayed non-significant variation of about 9.60% irrespective of sites. Among tropane alkaloid (TA), hyoscyamine was recorded as the most abundant constituent irrespective of the plant and site while apotropine accumulated in lesser quantity in A. acuminata than H. niger. However, apotropine demonstrated significant variation of 175% among both sites. The final concentration of quinolizidine (QA) and tropane alkaloid (TA) reflects the interplay between reflectance and absorbance of UV radiation response field. These findings suggest that spectral response of UV light contributes directly to alkaloid biosynthesis.

Optimized combination of dilution and refined QuEChERS to overcome matrix effects of six types of tea for determination eight neonicotinoid insecticides by ultra performance liquid chromatography-electrospray tandem mass spectrometry.

Liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) is a primary tool for analysis of low volatility compounds in complex matrices. However, complex matrices, such as different types of tea, complicate analysis through ionization suppression or enhancement. In this study, sample preparation by a refined QuEChERS method combined with a dilution strategy removed almost all matrix effects caused by six types of tea. Tea samples were soaked with water and extracted with acetonitrile, cleaned up with a combination of PVPP (160mg) and GCB (20mg), and dried. Dried extracts were diluted with 20mL acetonitrile/water (15:85, v/v) before analysis by UPLC-MS/MS. The average recoveries of eight neonicotinoid insecticides (dinotefuran, nitenpyram, thiamethoxam, imidacloprid, clothianidin, imidaclothiz, acetamiprid, and thiacloprid) ranged from 66.3 to 108.0% from tea samples spiked at 0.01-0.5mgkg(-1). Relative standard deviations were below 16% for all recovery tests. The limit of quantification ranged from 0.01 to 0.05mgkg(-1).

Contribution to the characterization of Opuntia spp. juices by LC-DAD-ESI-MS/MS.

Opuntia spp. fruits are considered as health promoting foods due to the diversity of bioactive molecules found in these fruits. The composition in organic acids, flavonols and betalains in the Opuntia ficus-indica juice from a region of Portugal was accomplished for the first time by liquid chromatography and tandem mass spectrometry using an electrospray ionization source operating in negative and positive mode. The methodology used allowed the detection of 44 compounds, from which 32 were identified. Isorhamnetin derivatives were the dominant flavonol glycosides. A total of 9 betalains including 6 betaxanthins and 3 betacyanin were also detected in the fruit juice samples and indicaxanthin, betanin and isobetanin were the major pigments. Phenolic acid and phenylpyruvic acid derivatives were also identified. To our knowledge, it is the first time derivative compounds from piscidic acid, phenolic compounds and betalains are characterized in cactus pear juice using a single LC-DAD-ESI-MS/MS method.

Validation of chemical compound library screening for transcriptional co-activator with PDZ-binding motif inhibitors using GFP-fused transcriptional co-activator with PDZ-binding motif.

Transcriptional co-activator with PDZ-binding motif (TAZ) plays versatile roles in cell proliferation and differentiation. It is phosphorylated by large tumor suppressor kinases, the core kinases of the tumor-suppressive Hippo pathway. Phosphorylation induces the cytoplasmic accumulation of TAZ and its degradation. In human cancers, the deregulation of the Hippo pathway and gene amplification enhance TAZ activity. TAZ interacts with TEA domain family members (TEAD), and upregulates genes implicated in epithelial-mesenchymal transition. It also confers stemness to cancer cells. Thus, TAZ activation provides cancer cells with malignant properties and worsens the clinical prognosis. Therefore, TAZ attracts attention as a therapeutic target in cancer therapy. We applied 18 606 small chemical compounds to human osteosarcoma U2OS cells expressing GFP-fused TAZ (GFP-TAZ), monitored the subcellular localization of GFP-TAZ, and selected 33 compounds that shifted GFP-TAZ to the cytoplasm. Unexpectedly, only a limited number of compounds suppressed TAZ-mediated enhancement of TEAD-responsive reporter activity. Moreover, the compounds that weakened TEAD reporter activity did not necessarily decrease the unphosphorylated TAZ. In this study, we focused on three compounds that decreased both TEAD reporter activity and unphosphorylated TAZ, and treated several human cancer cells with these compounds. One compound did not show a remarkable effect, whereas the other two compounds compromised the cell viability in certain cancer cells. In conclusion, the GFP-TAZ-based assay can be used as the first screening for compounds that inhibit TAZ and show anticancer properties. To develop anticancer drugs, we need additional assays to select the compounds.

Fabricating a novel label-free aptasensor for acetamiprid by fluorescence resonance energy transfer between NH2-NaYF4: Yb, Ho@SiO2 and Au nanoparticles.

Rare earth-doped upconversion nanoparticles have promising potential in the field of pesticide detection because of their unique frequency upconverting capability and high detection sensitivity. This paper reports a novel aptamer-based nanosensor for acetamiprid detection using fluorescence resonance energy transfer (FRET) between NH2-NaYF4: Yb, Ho@SiO2 (UCNPs) and gold nanoparticles (GNPs). Herein, GNPs as acceptors efficiently quench the fluorescence of UCNPs and acetamiprid specifically interacts with acetamiprid binding aptamer (ABA), causing the conformation changes of ABA from random coil to hairpin structure. Accordingly, ABA no longer stabilizes the GNPs in salt solution, leading to the varying aggregation extent of GNPs. Thus, the fluorescence of UCNPs are proportionally recovered. Under the optimized conditions, the enhancement efficiency was observed to increase linearly with the concentration of acetamiprid from 50 nM to 1000 nM, resulting in a relatively low limit of 3.2 nM. Additionally, the aptasensor demonstrated high selectivity to similar structure pesticides such as imidacloprid and chlorpyrifos, and further confirmed its application capacity in adulterated tea samples.

Sensitive determination of mixtures of neonicotinoid and fungicide residues in pollen and single bumblebees using a scaled down QuEChERS method for exposure assessment.

To accurately estimate exposure of bees to pesticides, analytical methods are needed to enable quantification of nanogram/gram (ng/g) levels of contaminants in small samples of pollen or the individual insects. A modified QuEChERS extraction method coupled with ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) analysis was tested to quantify residues of 19 commonly used neonicotinoids and fungicides and the synergist, piperonyl butoxide, in 100 mg samples of pollen and in samples of individual bumblebees (Bombus terrestris). Final recoveries ranged from 71 to 102 % for most compounds with a repeatability of below 20 % for both pollen and bumblebee extracts spiked at 5 and 40 ng/g. The method enables the detection of all compounds at sub-ng/g levels in both matrices and the method detection limits (MDL) ranged from 0.01 to 0.84 ng/g in pollen and 0.01 to 0.96 ng/g in individual bumblebees. Using this method, mixtures of neonicotinoids (thiamethoxam, clothianidin, imidacloprid and thiacloprid) and fungicides (carbendazim, spiroxamine, boscalid, tebuconazole, prochloraz, metconazole, fluoxastrobin, pyraclostrobin and trifloxystrobin) were detected in pollens of field bean, strawberry and raspberry at concentrations ranging from MDL, and in some bees, the fungicides carbendazim, boscalid, tebuconazole, flusilazole and metconazole were present at concentrations between 0.80 to 30 ng/g. This new method allows the analysis of mixtures of neonicotinoids and fungicides at trace levels in small quantities of pollen and individual bumblebees and thus will facilitate exposure assessment studies.

Monitoring and risk assessment of 74 pesticide residues in Pu-erh tea produced in Yunnan, China.

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.

Use of luminescent gunshot residues markers in forensic context.

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).

[Effects of amino acid on growth and secondary metabolites contents of adventitious roots of Tripterygium wilfordii].

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.