Extraction of domoic acid from seawater and urine using a resin based on 2-(trifluoromethyl)acrylic acid

A new solid-phase extraction (SPE) matrix with high affinity for the neurotoxin domoic acid (DA) was designed and tested. A computational modelling study led to the selection of 2-(trifluoromethyl)acrylic acid (TFMAA) as a functional monomer capable of imparting affinity towards domoic acid. Polymeric adsorbents containing TFMAA were synthesised and tested in high ionic strength solutions such as urine and seawater. The TFMAA-based polymers demonstrated excellent performance in solid-phase extraction of domoic acid, retaining the toxin while salts and other interfering compounds such as aspartic and glutamic acids were removed by washing and selective elution. It was shown that the TFMAA-based polymer provided the level of purification of domoic acid from urine and seawater acceptable for its quantification by high performance liquid chromatography-mass spectrometry (HPLC-MS) and enzyme-linked immunosorbent assay (ELISA) without any additional pre-concentration and purification steps.     

Applied Mathematics in the Secondary School

It is suggested that applied mathematics in the secondary school should be based on the practical investigation of everyday situations which lead to the setting up of various mathematical models. These situations should be selected so that problems of social and psychological importance are considered as well as dynamical and statistical problems. Activities of this kind in the areas of classical mechanics, networks, information theory and linear systems are outlined. These lead to models involving many different branches of mathematics. A syllabus embodying these suggestions is proposed.     

Bis(triphenylphosphine)copper (I) tetrahydroborate in the reduction of P-toluenesulphonylhydrazones and 2,4,6-triisopropylbenzenesulphonyl hydrazones (trisyl hdyrazones) to alkanes

Saturated ketones and aldehydes are converted via their $\text{p}$-toluenesulphonyl hydrazones to the corresponding alkanes by treatment with bis(triphenylphosphine) copper (I) tetrahydroborate; trisylhydrazones give moderate yields of alkanes at room temperature on treatment with bis(triphenylphosphine)copper (I) tetrahydroborate.     

Hydrogenation of

The course of the hydrogenation of [5]- and [6]metacyclophane (1b and 1c) and their thermochemistry is described. Both compounds are hydrogenated rapidly (within 10 s) to furnish the bridgehead olefins 13b and 12c. The accompanying hydrogenation enthalpies are -220 and -141 kJmol(-1), respectively. Strain energies (SE) and olefinic strains (OS) of a number of bridgehead olefins have been evaluated by DFT calculations; it was concluded that 13b belongs to the class of hyperstable olefins which correlates nicely with its reluctance to undergo hydrogenation. By combining experimental hydrogenation enthalpies and DFT calculations, SE of 187 and 121 kJmol(-1) were derived for 1b and 1c.     

Categorisation of Particulate Emissions from a Fluidised Catalytic Cracking Unit

Fluidized Catalytic Cracker Units (FCCU) are used in the oil refining industry to convert long chained hydrocarbons into shorter ones. At normal operations there is little concern regarding catalyst particle emission into the atmosphere from these devices. However, when the unit is started, higher than normal emission rates are common. FCCU stack emissions were tested and categorized in terms of metal composition and were compared with the operational conditions experienced under start up conditions. It was found that excessive emissions can be explained due to fluctuations in cyclone performance, the production of fine particles via attrition processes and the thermal fracture of particles. In addition to particle emissions, levels of emitted metals also fluctuate during the start up period, with the highest levels being experienced at the moment oil is re‐fed into the unit. The current paper summarises stack testing results as well as the operational conditions in order to identify the key causes of start up emissions and provide recommendations to reduce and manage particle emissions from refineries.     

Studies of deposition in hill cloud

Summary The occurrence of cloud at ground level over hills is particularly difficult to categorise and quantify in complex mountainous terrain, and has constituted a major part of our studies as described below. For routine calculations, concentrations in hill cloud have to be estimated from daily observations at the limited national network of air and precipitation monitoring stations, coupled with meteorological data, leading to additional complications. Further approximations have to be made to calculate deposition rates, and the preliminary estimates of bulk annual deposition given in this paper. However the observed pattern of forest damage raises questions about the large variations in exposure of individual trees, and the relevance of bulk annual deposition estimates averaged over large areas. A tentative approach to identifying particularly damaging episodic conditions for tree foliage is also outlined. Paper presented at the GNFAO/EURASAP Meeting, Turin, September 1989. To speed up publication, proofs were not sent to the authors and were supervised by the Scientific Committee.