Determination of sulfur contents of vegetable and marine oils by ion chromatography and indirect ultraviolet photometry of their combustion products

A simple method for the determination of total sulfur content in vegetable and marine oils is described. The method involves combustion of the oil sample in an oxygen bomb to convert all forms of sulfur to sulfate ions with subsequent determination of the sulfate by ion chromatography and indirect ultraviolet detection. The ultraviolet system described is more sensitive than conductivity detection and enables the method to be applied more widely. Application of the method to a variety of vegetable and marine oils showed the general occurrence of sulfur in fats and oils, albeit often at a low level. Among the samples examined, crude Canola oil had the highest sulfur content (25.0 mg/kg) followed by the marine oils (5.8-15.2 mg/kg) and the non-Cruciferae vegetable oils (2.0-6.1 mg/kg). To whom correspondence should be addressed.     

ASSESSMENT OF RED BLOOD CELL DEFORMABILITY BY CENTRIFUGAL SEDIMENTATION

A centrifugal sedimentation method (CSM) is proposed for the assessment of deformability of red blood cells. The method is based on the premise that a red blood cell (RBC) should deform in a centrifugal field due to the variation of the centrifugal acceleration with the distance from the center of rotation. This change in shape of the RBC leads to a change in the rate of sedimentation in the centrifugal field. The rate of sedimentation, which serves as a measure of deformability, is characterized by an apparent sedimentation coefficient (ASC) and its normalized value (NASC), which is calculated by comparison with a control group of normal RBCs. It has been shown that the NASC is sensitive to the speed of rotation, to treatments with glutaraldehyde, diamide, or chlorpromazine, to heat treatment and to osmotic pressure variations.     

Effect of some isothiocyanates on the hydrogenation of canola oil

Sulfur compounds were added to refined and bleached canola oil before hydrogenation in the form of allyl, heptyl and 2-phenethyl isothiocyanates, and the effects on hydrogenation rate, solid fat content and percentagetrans fatty acids were determined. The poisoning effect was most pronounced with allyl isothiocyanate and least with phenethyl isothiocyanate. As the amount of added sulfur increased, the hydrogenation rate decreased. Of the three isothiocyanates used, allyl isothiocyanate caused formation of larger amounts oftrans isomers. An increased sulfur level in the oil resulted in increased solid fat content andtrans isomer level. Allyl isothiocyanate also caused formation of larger amounts of solid fat than other isothiocyanates at all levels of sulfur addition.     

Protecting biodegradable coatings releasing antimicrobial agents

This article describes the synthesis and in vitro analysis of poly(ester anhydride) antimicrobial protection coatings. Poly(ester anhydride)s composed of ricinoleic acid, sebacic acid, terephthalic acid, and isophthalic acid were used in this study. The polymers were compatible with various fillers commonly used in paint preparation. The in vitro experiments showed that the polymers are able to release diuron, an antimicrobial agent, for months. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

LIQUID PHASE TRANSPORT PROPERTIES IN A HIGH PRESSURE PACKED COLUMN

A mathematical model of fluid flow and mass transfer in a packed bed was derived and used to evaluate the liquid phase axial dispersion and mass transfer coefficients under high pressure conditions. The least-squares method was used to evaluate the rate parameters from experimental breakthrough curves, and the agreement between the concentration curves predicted from rate parameters and those measured experimentally was good. Experiments were performed at 20 and 200°C with water as a solvent and nonporous soda-lime glass beads as packing. Although the axial dispersion coefficient was independent of temperature and pressure, the mass transport parameters were found to be pressure dependent.     

Axial dispersion and enterainment of particles in wakes of bubbles

The entrainment and dispersion of solid particles in bubble columns was investigated experimentally and heoretically. A mechanistic model for the dispersion caused by entrainment in wakes of large solitary bubbles was developed. The dispersion coefficient was found to be dependent on the bubble size, bubble frequency, particle settling velocity and column surface area. Experimental tests were conducted in a rectangular bubble column. The system consisted of air, water and copper powder. Spherical cap bubbles were produced by a single nozzle. Significant entrainment of particles in wakes of rising bubbles observed in the lower region of the column, whereas, turbulence seemed to dominate the dispersion in the upper region of the tank. Calculated particle distributions were found to be in good agreement with experimental data.     

Rechargeable sodium batteries—VI. Cycling behavior of VS2, ‘VCl3 + nS’ and NbS2Cl2 cathodes in molten NaAlCl4

The electrochemistry of VS₂ in molten NaAlCl₄ has been investigated in relation to its usefulness as a reversible positive electrode for sodium batteries operating in the moderate temperature range of 160–200°C. VS₂ reacted with NaAlCl₄ during early stages of cell cycling, and became VS₂Cl showing a reversible capacity of 2.8 electrons/vanadium. The electrochemistry of mixtures of VCl₃ and S in molten NaAlCl₄ showed similarities to that of VS₂Cl. The VS_xCl_y cathodes obtained via the two different routes exhibited excellent rechargeability as evidenced by the long-term cycling behavior of cells of the configuration, Na_(l)/β″-Al₂O₃/NaAlCl_4(l), cathode material. When NbS₂Cl₂ was used as the cathode material it underwent a structural change in the first cycle to form what appeared to be NbS₂Cl₂, the Nb analog of VS_xCl_y. The structurally modified niobium sulfur chloride cathode exhibited excellent rechargeability.     

Ethanol extraction of oil,gossypol and aflatoxin from cottonseed

Commercial processing of cottonseed requires hexane to extract and recover edible oil. Gossypol and aflatoxin are not removed from extracted meals. A bench-top extraction process with 95% (vol/vol) aqueous ethanol (EtOH) solvent has been developed that extracts all three of the above materials with a much less volatile solvent. In this process, cottonseed is pretreated and extracted with ambient 95% EtOH to remove gossypol and then extracted with hot 95% EtOH to extract oil and aflatoxin. Membranes and adsorption columns are used to purify the various extract streams, so that they can be recycled directly. A representative extracted meal contained a total gossypol content of 0.47% (a 70% reduction) and 3 ppb aflatoxin (a 95% reduction). Residual oil content was approximately 2%. Although the process is technically feasible, it is presently not economical unless a mill has a continual, serious aflatoxin contamination problem. However, if a plant cannot meet the hexane emission standards under the Clean Air Act of 1990, this process could provide a safer solvent that may expand the use and increase the value of cottonseed meal as a feed for nonruminants. Presented in part at the AOCS annual meeting, Toronto, Canada, May 1992.     

Production of cocoa butter-like fat from interesterification of vegetable oils

Cocoa butter-like fat was prepared from completely hydrogenated cottonseed and olive oils by enzymatic interesterification. The optimum reaction time to produce the major-component of cocoa butter, 1(3)-palmitoyl-3(1)-stearoyl-2-monoolein (POS), was 4 hr. The cocoa butter-like fat was isolated from the reaction mixture by two filtration steps. The yield of cocoa butter-like fat was 19%, based on the weight of the original oils. Chromatographic analysis of the product by reversephase high-performance liquid chromatography (HPLC) has shown it contains triglyceride components similar to those of cocoa butter, but that it has slightly more diglycerides. The melting point of this product, as measured by a differential scanning calorimeter, is 39°C, which compares well to the 36°C melting point of natural cocoa butter. Presented in part at the AOCS meeting in Cincinnati, Ohio, in 1989.     

The crystal state binding of dithionite to deoxy-hemoglobin

The crystal state binding of sodium ditbionite to deoxyhemoglobinis reported. Dithionite has been used extensively to deoxygenatehemoglobin and myoglobin and there has been considerable interestamong users of dithionite about its effect on protein structureand binding site(s). We have determined that dithionite bindsto deoxygenated hemoglobin crystals at the interface of twomolecules in the crystal lattice. Specific residues involvedin hydrogen bonds or salt interactions with dithionite includeHisll6 and Hisll7 of the ft subunit and Lysl6 of the ß₂subunit of the adjacent hemoglobin molecule. No binding wasobserved at the symmetry related Hisll6 and 117 ß1 residues.We have shown that dithionite does not affect the native hemoglobinstructure or the binding of several allosteric inhibitors tohemoglobin and can be used to mount T state crystals in theair