Versatile Control of

We demonstrate quantum control of ^{9}Be^{+} ions directly implemented by an optical frequency comb. Based on numerical simulations of the relevant processes in ^{9}Be^{+} for different magnetic field regimes, we demonstrate a wide applicability when controlling the comb's spectral properties. We introduce a novel technique for the selective and efficient generation of a spectrally tailored narrow-bandwidth optical frequency comb near 313 nm. We experimentally demonstrate internal state control and internal-motional state coupling of ^{9}Be^{+} ions implemented by stimulated-Raman manipulation using a spectrally optimized optical frequency comb. Our pulsed laser approach is a key enabling step for the implementation of quantum logic and quantum information experiments in Penning traps.

Tetraphasic polar organic chemical integrative sampler for the determination of a wide polarity range organic pollutants in water. The use of performance reference compounds and in-situ calibration.

In the present work, a homemade polar organic chemical integrative sampler (POCIS) was studied for the determination of 16 target analytes. The suitability of the combination of triphasic mixture (used in so called pesticides-POCIS) and octadecyl-functionalized silica gel (C18) as sorbent for POCIS was evaluated for the determination of alkylphenols (APs), several hormones, bisphenol-A (BPA), synthetic musk fragrances and herbicides such as trifluralin (Tri) and alachlor (Ala). With this purpose, POCIS laboratory calibration study, using a continuous-flow calibration system, was carried out in order to determine the uptake behavior and sampling rate (Rs) values for each target analyte. While the most hydrophobic compounds, (synthetic musk fragrances, some APs and Tri), showed poor linearity and low accumulation, a linear accumulation was observed for compounds whose logarithmic octanol-water partition coefficient (log Kow) ranged from 5.3 (4-tert-octylphenol, 4t-OP) to 3.1 (cis-androsterone, ADT). The Rs values obtained ranged from 0.190Lday-1 (4t-OP) to 0.042Lday-1 (BPA and equilin, EQ). The addition of C18 to the commonly used triphasic mixture increased the applicability of the POCIS sampler to compounds slightly more non-polar, such as 4t-OP. As far as we know, this is the first time that a combination of tetraphasic sorbent composed by the commercially available triphasic sorbent (Isolute ENV+polystyrene divinylbenzene and Ambersorb 1500 carbon dispersed on S-X3 Biobeads) and C18 was evaluated for passive sampling of the target analytes. The developed POCIS samplers were applied in field experiments from Halle (Germany) wastewater treatment plant (WWTP) effluent. Concerning the calculation of Rs values, the time weighted average (TWA) water concentration CWTWA values were determined considering three different approaches: (i) Rs from laboratory calibration (ii) Rs from laboratory calibration corrected with the use of performance reference compounds (PRCs) and (iii) Rs derived from field experiments or in-situ calibration. Several deuterated compounds such as, [2H3]-17ß-estradiol ([2H3]-E2), [2H4]-nonylphenol ([2H4]-NP), [2H4]-equilin ([2H4]-EQ), [2H3]-tonalide ([2H3]-AHTN) and [2H15]-musk xylene ([2H15]-MX) were also studied for their applicability as PRCs. Finally, a reasonable agreement between grab sampling and CWTWA was found when results from in-situ calibration were considered, but not when PRCs were used for correction.

Calibration and field test of the Polar Organic Chemical Integrative Samplers for the determination of 15 endocrine disrupting compounds in wastewater and river water with special focus on performance reference compounds (PRC).

In this work, home-made Polar Organic Chemical Integrative Samplers (POCIS) were studied for passive sampling of 15 endocrine disrupting compounds (4 alkylphenols and steroid hormones) in influent and effluent samples of wastewater treatment plants (WWTPs) as well as up- and downstream of the receiving river water. POCIS calibration at laboratory conditions was carried out using a continuous-flow calibration system. The influence of the exposure position of the POCIS within the calibration device, horizontal or vertical, to the water flow direction was evaluated. While the sampling rates of most of the target substances were not affected by the sampler position, for cis-ADT, E1, E2 and E3, the vertical position provided the highest analyte accumulation. Hence, the POCIS samplers were preferably exposed vertical to the water flow in overall experiments. Using the continuous-flow calibration device, lab-based sampling rates were determined for all the target compounds (RSBPA = 0.0326 L/d; RScisADT = 0.0800 L/d, RSE1 = 0.0398 L/d, RSEQ = 0.0516 L/d, RSTT = 0.0745 L/d, RSE2 = 0.0585 L/d, RSEE2 = 0.0406 L/d, RSNT = 0.0846 L/d, RSPG = 0.0478 L/d and RSE3 = 0.1468 L/d), except for DES, MeEE2, 4tOP, 4OP, 4NPs, where the uptake after 14 days POCIS exposure was found to be insignificant or indicated a no linear behaviour. Recoveries from POCIS extractions were in the range between 71 and 152% for most of the target analytes except for DES and E3 with around 59%. Good precision of the sampling procedure up till 20% was observed and limits of detection were at ng/L level. Two deuterated compounds ([(2)H3]-E2 and [(2)H4]-EQ) were successfully tested as performance reference compounds (PRC, [Formula: see text] = 0.0507 L/d and [Formula: see text] = 0.0543 L/d)). Finally, the POCIS samplers were tested for monitoring EDCs at two wastewater treatment plants, in Halle and Leipzig (Germany). BPA, E1, EQ, E2, MeEE2, NT, EE2, PG and E3 were quantified and their time-weighted average concentrations calculated on the basis of the lab-derived sampling rates were compared with the results based on conventional grab samples. While the influent concentration of BPA, cisADT, E1, TT, PG, EE2 reached the µg/L level, the rest of the target analytes were determined at ng/L. The analyte concentrations in the effluent never exceed ng/L level except for BPA. The concentration determined by spot sampling was partially lower (BPA, E1, TT) or comparable (EQ, E2, EE2, PG, E3) to the concentration obtained by POCIS using performance reference compounds (PRC).

Selective determination of estrogenic compounds in water by microextraction by packed sorbents and a molecularly imprinted polymer coupled with large volume injection-in-port-derivatization gas chromatography-mass spectrometry.

A fully automated protocol consisting of microextraction by packed sorbents (MEPS) coupled with large volume injection-in-port-derivatization-gas chromatography-mass spectrometry (LVI-derivatization-GC-MS) was developed to determine endocrine disrupting compounds (EDCs) such as alkylphenols, bisphenol A, and natural and synthetic hormons in river and waste water samples. During method optimization, the extraction parameters as ion strength of the water sample, the MEPS extraction regime, the volume of organic solvent used for the elution/injection step, the type of elution solvents and the selectivity of the sorbents were studied. For optimum in-port-derivatization, 10 µL of the derivatization reagent N,O-bis(trimethylsilyl)triufloroacetamide with 1% of trimethylchlorosilane (BSTFA+1% TMCS) was used. 17ß-Estradiol-molecularly imprinted polymer (MIP) and silica gel (modified with C-18) sorbents were examined for the enrichment of the target analytes from water samples and the obtained results revealed the high selectivity of the MIP material for extraction of substances with estrogen-like structures. Recovery values for most of the analytes ranged from 75 to 109% for the C18 sorbent and from 81 to 103% for the MIP material except for equilin (on C18 with only 57-66% recovery). Precision (n=4) of the entire analysis protocol ranged between 4% and 22% with both sorbents. Limits of detection (LODs) were at the low ngL(-1) level (0.02-87, C18 and 1.3-22, MIP) for the target analytes.

Comparison of different extraction solutions for the analysis of allergens in hen's egg.

An important requirement for the correct procedure of allergen analysis in hen's egg is to obtain complete and unaltered protein extracts. Besides the aim of a quantitative extraction of the allergens from the matrix, it is equally important not to alter their allergenic potential during the extraction process. This paper describes and compares six extraction solutions for the analysis of whole-egg proteins and allergens. These requirements were examined via protein determination according to Bradford [Bradford, M. M. (1976). Rapid and sensitive method for quantitation of microgram quantities of protein utilizing principle of protein-dye binding. Analytical Biochemistry, 72, 248-254] and Kjeldahl [Meyer, A. H. (2006). Lebensmittelrecht, Verlag C.H. Beck München, Stand: 1. February 2006, § 64, Lebensmittel- und Futtermittelgesetzbuch, Amtliche Sammlung von Untersuchungsmethoden, Nr. L 06.00-7] as well as the EAST-inhibition method. It could be demonstrated that the extraction with a urea solution (8M) led to significant interferences during the protein determination, and substantially reduced the allergenic potential of egg proteins. With all other extraction solutions adequate protein contents could be extracted. The highest protein content was achieved by the extraction with phosphate buffered saline followed by a Tween 20 solution, physiological saline, water, and acetate buffer. The results show that none of these extracts - except for the urea solution (8M) - was altered in its' allergenic potential.

Influence of maturation on the alteration of allergenicity of green pea (Pisum sativum L.).

The IgE-binding capacity of different maturation levels of green pea seeds (Pisum sativum L.) of the variety Maxigolt is examined to determine the influence of maturation on the alteration of allergenicity. Different protein extraction methods to get total protein extracts and the protein fractions glutelin, globulin, and albumin from different maturation levels of green pea seeds are applied to SDS-PAGE/silver staining as well as SDS-PAGE/immunoblotting and EAST inhibition experiments using sera of 15 green pea allergic individuals. The SDS-PAGE/silver-staining experiments show the continuous change of protein pattern during maturation. SDS-PAGE/immunoblot and EAST inhibition demonstrate that all levels of green pea seeds show relevant IgE-binding capacity, as do immature seeds. Total IgE-binding capacity rises with the progress of maturation. Although the main allergenic activity is dependent upon the albumin fraction, the glutelin and globulin fractions are also important. The implication of these results is an obvious allergenic potency of all maturation levels, even immature seeds, whereas an increase of allergenicity during maturation could be notched up. The highest allergenic potency is caused by the albumin fraction, but globulin and glutelin fractions also contribute to the allergenicity of green pea.

Diffusion-based calibration for solid-phase microextraction of benzene, toluene, ethylbenzene, p-xylene and chlorobenzenes from aqueous samples.

Short-term solid-phase microextraction (SPME) was performed to test a recently proposed semi-empirical model for the prediction of concentrations of analyte in water samples from the fibre-extracted mass without further calibration. The mass uptake rates obtained for benzene, toluene, ethylbenzene and p-xylene (BTEX) differ considerably from the before published, showing that interfibre comparability is a serious issue. The relative prediction errors are between -55% for benzene and +82% for p-dichlorobenzene under optimal conditions, i.e. they are by an order of magnitude higher than originally published. A sensitivity analysis shows the dominant influence of the estimated thickness of the diffusional boundary layer around the fibre on the concentration predicted. Empirical modification of the model equation for this parameter yields satisfactory results under the conditions tested for both BTEX and the selected chlorobenzenes.

Polydimethylsiloxane rod extraction, a novel technique for the determination of organic micropollutants in water samples by thermal desorption-capillary gas chromatography-mass spectrometry.

A novel, simple and inexpensive approach to absorptive extraction of organic compounds from environmental samples is presented. It consists of a polydimethylsiloxane rod used as an extraction media, enriched with analytes during shaking, then thermally desorbed and analyzed by GC-MS. Its performance was illustrated and evaluated for the enrichment of sub- to ng/l of selected chlorinated compounds (chlorobenzenes and polychlorinated biphenyls) in water samples. The new approach was compared to the stir bar sorptive extraction performance. A natural ground water sample from Bitterfeld, Germany, was also extracted using both methods, showing good agreement. The proposed approach presented good linearity, high sensitivity, good blank levels and recoveries comparable to stir bars, together with advantages such as simplicity, lower cost and higher feasibility.

Solid-phase microextraction fibre-water distribution constants of more hydrophobic organic compounds and their correlations with octanol-water partition coefficients.

Fibre coating-water distribution constants (Kfw) of more hydrophobic chemicals were determined with six different solid-phase microextraction fibre types (including a polyoctylmethylsiloxane (C8) prototype) by fibre exposure to agitated large-volume water samples lasting several days. The results obtained are comparable with Kfw values obtained under dynamic conditions. Octanol-water partition coefficients (Kow) were measured with the mixture of distributing substances to examine log Kfw-log Kow relationships based on a consistent dataset. Kfw values obtained with liquid polymer fibre coatings correlate reasonably well with the hydrophobicity of the test compounds (with decreasing sensitivity in the following order: 7 microm polydimethylsiloxane (PDMS)>100 microm PDMS>C8>polyacrylate) whereas this is not the case with the PDMS-divinylbenzene (DVB) and Carbowax-DVB fibres, partially porous coatings which provide the highest Kfw values for all substances tested.

Application of different RP-HPLC methods for the determination of the octanol/water partition coefficient of selected tetrachlorobenzyltoluenes.

Reversed-phase high-performance liquid chromatography (RP-HPLC) in both, isocratic and gradient elution mode (stationary phase: LiChrospher 100 RP-18; mobile phase: water/methanol or water/acetonitrile) was used for a renewed determination of octanol/water partition coefficients (Kow) of selected tetrachlorobenzyltoluene (TCBT) isomers. Reported Kow values identify this substance class as very hydrophobic but the data are relatively inconsistent. Based on a series of calibration runs with hydrophobic reference substances of different chemical structure at various eluent compositions we tested different approaches for the evaluation of isocratic retention factors (logk) and found substantial differences between the direct calibration procedure at special methanol volume fractions in the mobile phase (0.95-0.80) and the use of retention factors extrapolated to pure water as eluent (logkw). The logKow values obtained for the TCBTs with the latter approach are around 0.5 units higher and closer to literature data. The gradient elution experiments yield slightly better results compared to the isocratic direct calibration procedure, but not as good as the calibration with log kw. In addition, the use of the RP-HPLC retention factors for estimating sorption coefficients (Koc) of TCBT isomers is discussed.

Membrane-enclosed sorptive coating. an integrative passive sampler for monitoring organic contaminants in water.

An integrative sampler that consists of a bar coated with poly(dimethylsiloxane) (PDMS) enclosed in a dialysis membrane bag has been developed combining the advantages of the passive sampling approach with solventless preconcentration of organic solutes from aqueous matrixes and subsequent desorption of the sequestered analytes on-line with a capillary GC/MS system. The performance of the sampler was tested for integrative sampling of hydrophobic persistent organic pollutants including gamma-hexachlorocyclohexane, hexachlorobenzene, 2,2'-bis(4-chlorophenyl)-1,1'-dichloroethylene, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls in the laboratory in a continuous-flow system. Linear uptake of all test analytes during exposure periods up to one week has been observed, and concentration proportionality of response of the sampler has been demonstrated. Over the range of controlled laboratory conditions, the magnitude of sampling rate values varied from 47 to 700 microL h(-1) per sampler. The uptake rate of chemicals was dependent on their molecular mass, as well as on the partition coefficient between the PDMS and water. A decrease in sampling rates with decreasing water temperature was observed. The sampling device has the potential to detect low aqueous concentrations (ng to pg L(-1)) of test substances.

Stability of food allergens and allergenicity of processed foods.

The allergenicity of food could be altered by several processing procedures. For various foods of animal and plant origin the available literature on this alteration is described. Investigations on hidden allergens in food products are also dealt with.

Determination of the IgE-binding activity of soy lecithin and refined and non-refined soybean oils.

In the present study refined and non-refined soybean oils as well as soy lecithins were investigated for residual allergenicity and compared with extracts from native soybeans. By means of immunoblotting and EAST inhibition experiments no IgE-binding activity was detectable in refined soybean oils, which is probably due to thermal treatment during the refining. The investigated non-refined oils and soy lecithins showed a residual IgE-binding activity. In addition in the lecithin extracts a new IgE-binding structure with a molecular mass of approximately 16 kDa was detectable.

Determination of the allergenicity of various hazelnut products by immunoblotting and enzyme allergosorbent test inhibition.

Although allergic reactions to hazelnuts are common especially in Europe, there are only a few investigations with regard to the influence of processing on the IgE-binding potency of hazelnut proteins. In this study the allergenicity of different hazelnut products, such as chocolate, nougat products, croquant or cookies, was examined by sodium dodecyl sulfatepolyacrylamide gel electrophoresis (SDS-PAGE), immunoblotting and enzyme allergosorbent test (EAST) inhibition experiments using sera of 17 hazelnut-allergic individuals. In only a few cases did the immunoblotting experiments yield positive results as regards the allergenicity of the investigated products. By means of EAST inhibition a residual IgE-binding potency could be detected in almost all of the product extracts. Therefore hazelnuts are a potential hazard to allergic people even as an ingredient of processed foods.

Use of semipermeable membrane devices (SPMDs). Determination of bioavailable, organic, waterborne contaminants in the industrial region of Bitterfeld, Saxony-Anhalt, Germany.

Triolein-containing semipermeable membrane devices (SPMDs) were employed as passive samplers to provide data on the bioavailable fraction of organic, waterborne, organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polynuclear aromatic hydrocarbons (PAHs) in streams flowing through a highly polluted industrial area of Bitterfeld in Saxony-Anhalt, Germany. The contamination of the region with organic pollutants originates in wastewater effluents from the chemical industry, from over one-hundred years of lignite exploitation, and from chemical waste dumps. The main objective was to characterise time-integrated levels of dissolved contaminants, to use them for identification of spatial trends of contamination, and their relationship to potential pollution sources. SPMDs were deployed for 43 days in the summer of 1998 at four sampling sites. The total concentration of pollutants at sampling sites was found to range from a low of 0.8 microgram/SPMD to 25 micrograms/SPMD for PAHs, and from 0.4 microgram/SPMD to 22 micrograms/SPMD for OCPs, respectively. None of the selected PCB congeners was present at quantifiable levels at any sampling site. A point source of water pollution with OCPs and PAHs was identified in the river system considering the total contaminant concentrations and the distribution of individual compounds accumulated by SPMDs at different sampling sites. SPMD-data was also used to estimate average ambient water concentrations of the contaminants at each field site and compared with concentrations measured in bulk water extracts. The truly dissolved or bioavailable portion of contaminants at different sampling sites ranged from 4% to 86% for the PAHs, and from 8% to 18% for the OCPs included in the estimation. The fraction of individual compounds found in the freely dissolved form can be attributed to the range of their hydrophobicity. In comparison with liquid/liquid extraction of water samples, the SPMD method is more suitable for an assessment of the background concentrations of hydrophobic organic contaminants because of substantially lower method quantification limits. Moreover, contaminant residues sequestered by the SPMDs represent an estimation of the dissolved or readily bioavailable concentration of hydrophobic contaminants in water, which is not provided by most analytical approaches.

Characterization of cross-reacting allergens in mango fruit.

BACKGROUND: Allergic reactions to mango fruit have become increasingly important. A cross-reaction between mango fruit, various other foods, and respiratory allergens has been assumed but not investigated until now. METHODS: The sera of nine patients were used to characterize cross-reacting allergens in mango fruits by EAST inhibition and immunoblot inhibition. RESULTS AND CONCLUSIONS: EAST inhibition and immunoblot inhibition demonstrated that cross-reactions between mango fruits, mugwort pollen, birch pollen, celery, and carrot are based on allergens related to Bet v 1 and Art v 1, the major allergens of birch and mugwort pollen, respectively.

Polyaromatic hydrocarbon concentrations and patterns in sediments and surface water of the Mansfeld region, Saxony-Anhalt, Germany.

The composition and spatial distribution of polyaromatic hydrocarbons (PAHs) and their relation to potential pollution sources were investigated in the Böse Sieben Creek, Saxony-Anhalt, Germany, using two techniques: semipermeable membrane devices (SPMDs) and sediment analysis. SPMD is an integrative device that passively samples hydrophobic chemicals of low to moderate molecular weight (< 600 Da) in water. SPMDs were placed in water for 34 days at three sites where sediments were also sampled. Fifteen PAHs were determined in SPMDs and in sediment samples to evaluate the concentration levels and specific PAH patterns. Time-weighted average aqueous PAH concentrations were estimated from the PAH amount accumulated in SPMDs during the deployment period using previously reported sampling rates. Sediment-water partition coefficients were used to estimate PAH concentrations in pore water from sediments. Calculated pore water concentrations were, on average, almost three orders of magnitude higher than those calculated from SPMDs. Thus, in addition to contamination from other sources, the water concentration at the sampling sites might be elevated due to contaminant mobilization from historically contaminated sediments. Relative PAH patterns from SPMDs and sediment were compared using principal component analysis, and were correlated with the PAH patterns from different potential contamination sources, including Theisen sludge, one of the by-products of the smelting process for copper production in the region in the past, which is likely to be the main contamination source of PAHs. Moreover, three origin indices (concentration ratios of PAH isomer pairs) were used to evaluate the suitability of these compounds as tracers to distinguish between the contamination arising from different sources. The evaluation of contaminant patterns permits the conclusion that the PAHs are of pyrolytic, industrial origin, possibly including contamination by Theisen sludge, and rules out a petrogenic source for the hydrocarbons.

Determination of polycyclic aromatic hydrocarbons in waste water by off-line coupling of solid-phase microextraction with column liquid chromatography.

A new method for the determination of polycyclic aromatic hydrocarbons (PAHs) in waste water using solvent-free solid-phase microextraction (SPME) is described. The PAHs are extracted with a 100 microm polydimethylsiloxane (PDMS) fiber, desorbed in 40 microl acetonitrile and measured with LC and fluorescence detection. The detection limits of this very simple method under the given conditions (extraction from 5 ml sample, extraction time 1 h) are in the range of 1-6 ng l(-1). The standard deviations (n = 6) at a concentration level of 0.8 microg l(-1) are between 1.8 and 14.4%. The procedure was used for the determination of PAHs in contaminated water samples.

Urease inhibition: a tool for toxicity identification in sediment elutriates.

A method for the detection and confirmation of heavy metal toxicants in sediment elutriates based on a urease inhibition assay, ICP-AES analysis and EDTA chelation in the frame of toxicity identification evaluation (TIE) is presented. Zinc was identified as the major toxicant in pHstat elutriates of sediments of the river Saale (Germany). Implications of natural and anthropogenic chelating agents, which are frequently present in environmental samples, on toxicity confirmation of heavy metals based on the toxic unit approach are discussed.

Kinetics of the arsenite oxidation in seepage water from a tin mill tailings pond.

The kinetic of the oxidation of trivalent arsenic was investigated in synthetic as well as in natural samples of a tin mill seepage water. The influence of ferric ions and solid MnO(2) on the process was studied. To determine the time dependence of the concentrations of the arsenic species, a series of samples were taken sequentially and analysed by coupling of ionchromatographic separation and ICP-MS detection. To investigate the naturally occurring oxidation reaction, original seepage water samples were filtered and spiked with As(III) (1 mg l(-1)) and Fe(II) (10 mg l(-1)) and shaken providing intensive contact with the air. Additional synthetic samples buffered with carbonate were used in similar experiments to simplify the system. The reaction was incomplete in the presence of excess of iron for both types of samples. The oxidation of As(III) was complete within 8 h in the presence of MnO(2) (10 mg), but there was a difference in oxidation rates between the natural and the synthetic samples. The results are discussed with respect to the redox potentials and equilibrium constants.