Several techniques for the preparation of flour from carcasses of the Pantanal alligator (Caiman crocodilus yacare)

AbstractFlour prepared via current assay methodologies from the carcasses of the Pantanal alligator (Caiman crocodilus yacare) was analyzed for its chemical composition, minerals, fatty acids, and sensorial profile. Carcasses of the Pantanal alligator, originating from the Coocrijapan scientific zoo, Cáceres MT Brazil, were utilized. The carcasses were cooked for 60 minutes in a pressure cooker with water containing 2% salt and 5% chimichurri. The cooked carcasses were then ground and the mass was used for the manufacture of flour via three techniques: non-smoked, hot-smoked, and liquid-smoked. After each technique, the carcasses were dehydrated at 60ºC for 3h and were ground. Alligator flour was then produced. The moisture of liquid-smoked flour (10.97%) was higher than that of non-smoked flour (3.78%) and hot-smoked flour (4.43%). The flours provided high protein (57.11% - 58.27%) and ash (23.45 – 26.42%) rates, and were predominantly calcium (6.77% - 7.69%), phosphorus (3.67% - 4.05%), and iron (73.13 – 273.73 ppm/100 mg). Smoked-flour had a better acceptance rate by tasters when compared to non-smoked flour. Results show that flours produced from alligator carcasses had high protein, ash, and mineral rates and a reasonable acceptability by most tasters.

The development of automated methods for the determination of trace concentrations of carbomate pesticides in water using solid sorbent pre-concentration methods and high performance liquid chromatography /

Several automated reversed-phase HPLC methods have been developed to determine trace concentrations of carbamate pesticides (which are of concern in Ontario environmental samples) in water by utilizing two solid sorbent extraction techniques. One of the methods is known as on-line pre-concentration'. This technique involves passing 100 milliliters of sample water through a 3 cm pre-column, packed with 5 micron ODS sorbent, at flow rates varying from 5-10 mUmin. By the use of a valve apparatus, the HPLC system is then switched to a gradient mobile phase program consisting of acetonitrile and water. The analytes, Propoxur, Carbofuran, Carbaryl, Propham, Captan, Chloropropham, Barban, and Butylate, which are pre-concentrated on the pre-column, are eluted and separated on a 25 cm C-8 analytical column and determined by UV absorption at 220 nm. The total analytical time is 60 minutes, and the pre-column can be used repeatedly for the analysis of as many as thirty samples. The method is highly sensitive as 100 percent of the analytes present in the sample can be injected into the HPLC. No breakthrough of any of the analytes was observed and the minimum detectable concentrations range from 10 to 480 ng/L. The developed method is totally automated for the analysis of one sample. When the above mobile phase is modified with a buffer solution, Aminocarb, Benomyl, and its degradation product, MBC, can also be detected along with the above pesticides with baseline resolution for all of the analytes. The method can also be easily modified to determine Benomyl and MBC both as solute and as particulate matter. By using a commercially available solid phase extraction cartridge, in lieu of a pre-column, for the extraction and concentration of analytes, a completely automated method has been developed with the aid of the Waters Millilab Workstation. Sample water is loaded at 10 mL/min through a cartridge and the concentrated analytes are eluted from the sorbent with acetonitrile. The resulting eluate is blown-down under nitrogen, made up to volume with water, and injected into the HPLC. The total analytical time is 90 minutes. Fifty percent of the analytes present in the sample can be injected into the HPLC, and recoveries for the above eight pesticides ranged from 84 to 93 percent. The minimum detectable concentrations range from 20 to 960 ng/L. The developed method is totally automated for the analysis of up to thirty consecutive samples. The method has proven to be applicable to both purer water samples as well as untreated lake water samples.

Study of the application of the high performance liquid chromatography-particle beam interface-mass spectrometry technique on some pesiticides and the reduction phenomena in the system

This work includes two major parts. The first part of the work concentrated on the studies of the application of the highperfonnance liquid chromatography-particle beam interface-mass spectrometry system of some pesticides. Factors that have effects on the detection sensitivity were studied. The linearity ranges and detection limits of ten pesticides are also given in this work. The second part of the work concentrated on the studies of the reduction phenomena of nitro compounds in the HPLC-PB-MS system. Direct probe mass spectrometry and gas chromatography-mass spectrometry techniques were also used in the work. Factors that have effects on the reduction of the nitro compounds were studied, and the possible explanation is proposed. The final part of this work included the studies of reduction behavior of some other compounds in the HPLC-PB-MS system, included in them are: quinones, sulfoxides, and sulfones.

Développement de techniques analytiques pour la détermination des agents anti-infectieux dans les eaux environnementales

Les agents anti-infectieux sont utilisés pour traiter ou prévenir les infections chez les humains, les animaux, les insectes et les plantes. L’apparition de traces de ces substances dans les eaux usées, les eaux naturelles et même l’eau potable dans plusieurs pays du monde soulève l’inquiétude de la communauté scientifique surtout à cause de leur activité biologique. Le but de ces travaux de recherche a été d’étudier la présence d’anti-infectieux dans les eaux environnementales contaminées (c.-à-d. eaux usées, eaux naturelles et eau potable) ainsi que de développer de nouvelles méthodes analytiques capables de quantifier et confirmer leur présence dans ces matrices. Une méta-analyse sur l’occurrence des anti-infectieux dans les eaux environnementales contaminées a démontré qu’au moins 68 composés et 10 de leurs produits de transformation ont été quantifiés à ce jour. Les concentrations environnementales varient entre 0.1 ng/L et 1 mg/L, selon le composé, la matrice et la source de contamination. D’après cette étude, les effets nuisibles des anti-infectieux sur le biote aquatique sont possibles et ces substances peuvent aussi avoir un effet indirect sur la santé humaine à cause de sa possible contribution à la dissémination de la résistance aux anti-infecteiux chez les bactéries. Les premiers tests préliminaires de développement d’une méthode de détermination des anti-infectieux dans les eaux usées ont montré les difficultés à surmonter lors de l’extraction sur phase solide (SPE) ainsi que l’importance de la sélectivité du détecteur. On a décrit une nouvelle méthode de quantification des anti-infectieux utilisant la SPE en tandem dans le mode manuel et la chromatographie liquide couplée à la spectrométrie de masse en tandem (LC-MS/MS). Les six anti-infectieux ciblés (sulfaméthoxazole, triméthoprime, ciprofloxacin, levofloxacin, clarithromycin et azithromycin) ont été quantifiés à des concentrations entre 39 et 276 ng/L dans les échantillons d’affluent et d’effluent provenant d’une station d’épuration appliquant un traitement primaire et physico- chimique. Les concentrations retrouvées dans les effluents indiquent que la masse moyenne totale de ces substances, déversées hebdomadairement dans le fleuve St. Laurent, était de ~ 2 kg. En vue de réduire le temps total d’analyse et simplifier les manipulations, on a travaillé sur une nouvelle méthode de SPE couplée-LC-MS/MS. Cette méthode a utilisé une technique de permutation de colonnes pour préconcentrer 1.00 mL d’échantillon dans une colonne de SPE couplée. La performance analytique de la méthode a permis la quantification des six anti-infectieux dans les eaux usées municipales et les limites de détection étaient du même ordre de grandeur (13-60 ng/L) que les méthodes basées sur la SPE manuelle. Ensuite, l’application des colonnes de SPE couplée de chromatographie à débit turbulent pour la préconcentration de six anti-infectieux dans les eaux usées a été explorée pour diminuer les effets de matrice. Les résultats obtenus ont indiqué que ces colonnes sont une solution de réchange intéressante aux colonnes de SPE couplée traditionnelles. Finalement, en vue de permettre l’analyse des anti-infectieux dans les eaux de surface et l’eau potable, une méthode SPE couplée-LC-MS/MS utilisant des injections de grand volume (10 mL) a été développée. Le volume de fuite de plusieurs colonnes de SPE couplée a été estimé et la colonne ayant la meilleure rétention a été choisie. Les limites de détection et de confirmation de la méthode ont été entre 1 à 6 ng/L. L’analyse des échantillons réels a démontré que la concentration des trois anti-infectieux ciblés (sulfaméthoxazole, triméthoprime et clarithromycine) était au dessous de la limite de détection de la méthode. La mesure des masses exactes par spectrométrie de masse à temps d’envol et les spectres des ions produits utilisant une pente d’énergie de collision inverse dans un spectromètre de masse à triple quadripôle ont été explorés comme des méthodes de confirmation possibles.

Liquid phase benzoylation of arenes over iron promoted sulphated zirconia

The present work undertakes the preparation and physico-chemical characterisation of iron promoted sulphated zirconia (SZ) with different amounts of iron loading and their application to Friedel-Crafts benzoylation of benzene, toluene and xylene under different experimental conditions, XRD and laser Raman techniques reveal the stabilisation of the tetragonal phase of zirconia and the existence of iron in highly dispersed form as Fe203 on the catalyst surface. The surface acidic properties were determined by ammonia temperature programmed desorption (TPD) and perylene adsorption, The results were supported by the TGA studies after adsorption of pyridine and 2,6-dimethylpyridine (2,6-DMP), Strong Lewis acid sites on the surface, which are evident from TPD and perylene adsorption studies. explain the high catalytic activity of the systems towards benzoylation. The experimental results provide evidence for the truly heterogeneous nature of the reaction. The studies also establish the resistance to deactivation in the metal incorporated sulphated systems.

Vanadia supported on ceria: Characterization and activity in liquid-phase oxidation of ethylbenzene

Vanadia/ceria catalysts (2–10 wt% of V2O5) were prepared by wet impregnation of ammonium metavanadate in oxalic acid solution. Structural characterization was done with energy dispersive X-ray analysis (EDX), powder X-ray diffraction (XRD), BET surface area measurements, FT-IR spectroscopy and nuclear magnetic spectral analysis (51V MASNMR). XRD and 51V MASNMR results show highly dispersed vanadia species at lower loadings and the formation of CeVO4 phase at higher V2O5 loading. The catalytic activity of catalysts was conducted in liquid phase oxidation of ethylbenzene with H2O2 as oxidant. The oxidation activity is increased with loading up to 8 wt% V2O5 and then decreased with further increase in V2O5 content to 10 wt%. Different vanadia species evidenced by various techniques were found to be selective towards ethylbenzene oxidation. The CeVO4 formation associated with increased concentration of vanadia on ceria results the production of acetophenone along with 2-hydroxyacetophenone.

Simultaneous determination of nonlinear optical and thermo-optic parameters of liquid samples

The authors apply the theory of photothermal lens formation and also that of pure optical nonlinearity to account for the phase modulation in a beam as it traverses a nonlinear medium. It is used to simultaneously determine the nonlinear optical refraction and the thermo-optic coefficient. They demonstrate this technique using some metal phthalocyanines dissolved in dimethyl sulfoxide, irradiated by a Q-switched Nd:YAG laser with 10 Hz repetition rate and a pulse width of 8 ns. The mechanism for reverse saturable absorption in these materials is also discussed.

Investigation of liquid MALDI and optimization for instrument tuning and quantitative measurements

The success of Matrix-assisted laser desorption / ionisation (MALDI) in fields such as proteomics has partially but not exclusively been due to the development of improved data acquisition and sample preparation techniques. This has been required to overcome some of the short comings of the commonly used solid-state MALDI matrices such as - cyano-4-hydroxycinnamic acid (CHCA) and 2,5-dihydroxybenzoic acid (DHB). Solid state matrices form crystalline samples with highly inhomogeneous topography and morphology which results in large fluctuations in analyte signal intensity from spot to spot and positions within the spot. This means that efficient tuning of the mass spectrometer can be impeded and the use of MALDI MS for quantitative measurements is severely impeded. Recently new MALDI liquid matrices have been introduced which promise to be an effective alternative to crystalline matrices. Generally the liquid matrices comprise either ionic liquid matrices (ILMs) or a usually viscous liquid matrix which is doped with a UV lightabsorbing chromophore [1-3]. The advantages are that the droplet surface is smooth and relatively uniform with the analyte homogeneously distributed within. They have the ability to replenish a sampling position between shots negating the need to search for sample hot-spots. Also the liquid nature of the matrix allows for the use of additional additives to change the environment to which the analyte is added.

Liquid AP-UV-MALDI enables stable ion yields of multiply charged peptide and protein ions for sensitive analysis by mass spectrometry

In biological mass spectrometry (MS), two ionization techniques are predominantly employed for the analysis of larger biomolecules, such as polypeptides. These are nano-electrospray ionization [1, 2] (nanoESI) and matrix-assisted laser desorption/ionization [3, 4] (MALDI). Both techniques are considered to be “soft”, allowing the desorption and ionization of intact molecular analyte species and thus their successful mass-spectrometric analysis. One of the main differences between these two ionization techniques lies in their ability to produce multiply charged ions. MALDI typically generates singly charged peptide ions whereas nanoESI easily provides multiply charged ions, even for peptides as low as 1000 Da in mass. The production of highly charged ions is desirable as this allows the use of mass analyzers, such as ion traps (including orbitraps) and hybrid quadrupole instruments, which typically offer only a limited m/z range (< 2000–4000). It also enables more informative fragmentation spectra using techniques such as collisioninduced dissociation (CID) and electron capture/transfer dissociation (ECD/ETD) in combination with tandem MS (MS/MS). [5, 6] Thus, there is a clear advantage of using ESI in research areas where peptide sequencing, or in general, the structural elucidation of biomolecules by MS/MS is required. Nonetheless, MALDI with its higher tolerance to contaminants and additives, ease-of-operation, potential for highspeed and automated sample preparation and analysis as well as its MS imaging capabilities makes it an ionization technique that can cover bioanalytical areas for which ESI is less suitable. [7, 8] If these strengths could be combined with the analytical power of multiply charged ions, new instrumental configurations and large-scale proteomic analyses based on MALDI MS(/MS) would become feasible.

Spatial variability of liquid cloud and rain: observations and microphysical effects

Spatial variability of liquid cloud water content and rainwater content is analysed from three different observational platforms: in situ measurements from research aircraft, land-based remote sensing techniques using radar and lidar, and spaceborne remote sensing from CloudSat. The variance is found to increase with spatial scale, but also depends strongly on the cloud or rain fraction regime, with overcast regions containing less variability than broken cloud fields. This variability is shown to lead to large biases, up to a factor of 4, in both the autoconversion and accretion rates estimated at a model grid scale of ≈40 km by a typical microphysical parametrization using in-cloud mean values. A parametrization for the subgrid variability of liquid cloud and rainwater content is developed, based on the observations, which varies with both the grid scale and cloud or rain fraction, and is applicable for all model grid scales. It is then shown that if this parametrization of the variability is analytically incorporated into the autoconversion and accretion rate calculations, the bias is significantly reduced.

Evaluation of water properties in HEA–HEMA hydrogels swollen in aqueous-PEG solutions using thermoanalytical techniques

Hydrogels are polymeric materials used in many pharmaceutical and biomedical applications due to their ability to form 3D hydrophilic polymeric networks, which can absorb large amounts of water. In the present work, polyethylene glycols (PEG) were introduced into the hydrogel liquid phase in order to improve the mechanical properties of hydrogels composed of 2-hydroxyethylacrylate and 2-hydroxyethylmethacrylate (HEA–HEMA) synthesized with different co-monomer compositions and equilibrated in water or in 20 % water–PEG 400 and 600 solutions. The thermoanalytical techniques [differential scanning calorimetry (DSC) and thermogravimetry (TG)] were used to evaluate the amount and properties of free and bound water in HEA–HEMA hydrogels. The internal structure and the mechanical properties of hydrogels were studied using scanning electron microscopy and friability assay. TG “loss-on-drying” experiments were applied to study the water-retention properties of hydrogels, whereas the combination of TG and DSC allowed estimating the total amount of freezable and non-freezing water in hydrogels. The results show that the addition of viscous co-solvent (PEG) to the liquid medium results in significant improvement of the mechanical properties of HEA–HEMA hydrogels and also slightly retards the water loss from the hydrogels. A redistribution of free and bound water in the hydrogels equilibrated in mixed solutions containing 20 vol% of PEGs takes place.

Coupling liquid MALDI MS to liquid chromatography

Matrix-assisted laser desorption/ionisation (MALDI) coupled with time-of-flight (TOF) mass spectrometry (MS) is a powerful tool for the analysis of biological samples, and nanoflow high-performance liquid chromatography (nanoHPLC) is a useful separation technique for the analysis of complex proteomics samples. The off-line combination of MALDI and nanoHPLC has been extensively investigated and straightforward techniques have been developed, focussing particularly on automated MALDI sample preparation that yields sensitive and reproducible spectra. Normally conventional solid MALDI matrices such as α-cyano-4-hydroxycinnamic acid (CHCA) are used for sample preparation. However, they have limited usefulness in quantitative measurements and automated data acquisition because of the formation of heterogeneous crystals, resulting in highly variable ion yields and desorption/ ionization characteristics. Glycerol-based liquid support matrices (LSM) have been proposed as an alternative to the traditional solid matrices as they provide increased shot-to-shot reproducibility, leading to prolonged and stable ion signals and therefore better results. This chapter focuses on the integration of the liquid LSM MALDI matrices into the LC-MALDI MS/MS approach in identifying complex and large proteomes. The interface between LC and MALDI consists of a robotic spotter, which fractionates the eluent from the LC column into nanoliter volumes, and co-spots simultaneously the liquid matrix with the eluent fractions onto a MALDI target plate via sheath flow. The efficiency of this method is demonstrated through the analysis of trypsin digests of both bovine serum albumin (BSA) and Lactobacillus plantarum WCFS1 proteins.

Liquid crystalline cellulosic elastomers: free standing anisotropic films under stretching

The structure and local ordering of 1,6-hexamethylenediisocyanate-(acetoxypropy1) cellulose (HDI-APC) liquid crystalline elastomer thin films are investigated by using X-ray diffraction and scattering techniques. Optical microscopy and mechanical essays are performed to complement the investigation. The study is performed in films subjected or not to an uniaxial stress. Our results indicate that the film is constituted by a bundle of helicoidal fiber-like structure, where the cellobiose block spins around the axis of the fiber, like a string-structure in a smectic-like packing, with the pitch defined by a smectic-like layer. The fibers are in average perpendicular to the smectic-like planes. Without the stretch, these bundles are warped, only with a residual orientation along the casting direction. The stretch orients the bundles along it, increasing the smectic-like and the nematic-like ordering of the fibers. Under stress, the network of molecules which connects the cellobiose blocs and forms the cellulosic matrix tends to organize their links in a hexagonal-like structure with lattice parameter commensurate to the smectic-like structure.

Optical Characterization and Optimization of Display Components : Some Applications to Liquid-Crystal-Based and Electrochromics-Based Devices

This dissertation is focused on theoretical and experimental studies of optical properties of materials and multilayer structures composing liquid crystal displays (LCDs) and electrochromic (EC) devices. By applying spectroscopic ellipsometry, we have determined the optical constants of thin films of electrochromic tungsten oxide (WOx) and nickel oxide (NiOy), the films’ thickness and roughness. These films, which were obtained at spattering conditions possess high transmittance that is important for achieving good visibility and high contrast in an EC device. Another application of the general spectroscopic ellipsometry relates to the study of a photo-alignment layer of a mixture of azo-dyes SD-1 and SDA-2. We have found the optical constants of this mixture before and after illuminating it by polarized UV light. The results obtained confirm the diffusion model to explain the formation of the photo-induced order in azo-dye films. We have developed new techniques for fast characterization of twisted nematic LC cells in transmissive and reflective modes. Our techniques are based on the characteristics functions that we have introduced for determination of parameters of non-uniform birefringent media. These characteristic functions are found by simple procedures and can be utilised for simultaneous determination of retardation, its wavelength dispersion, and twist angle, as well as for solving associated optimization problems. Cholesteric LCD that possesses some unique properties, such as bistability and good selective scattering, however, has a disadvantage – relatively high driving voltage (tens of volts). The way we propose to reduce the driving voltage consists of applying a stack of thin (~1µm) LC layers. We have studied the ability of a layer of a surface stabilized ferroelectric liquid crystal coupled with several retardation plates for birefringent color generation. We have demonstrated that in order to accomplish good color characteristics and high brightness of the display, one or two retardation plates are sufficient.