Veterinary Investigation Service and its role in toxicological investigation in the East Midlands (1956-1988)

For seventy years, the Sutton Bonington Veterinary Investigation Centre provided a diagnostic and advisory service for the veterinary practices situated in the East Midlands of the United Kingdom. A submission is made that the Centre was successful in the investigation and recording of animal diseases. Its origin and the history of the state diagnostic laboratories are given.The mixed farming of the region was often contiguous to industry as in Derbyshire, where lead mining has continued to represent a serious threat to stock owners. The geology, geomorphology and the extraction of minerals in the region are described. Lead contamination of pasture has occurred, with consequent poisoning of grazing animals, for over two hundred years.Three investigations of such poisonings are described, and also a case of contamination of land with lead fumes. There is a description of the losses, and of the remedial measures taken,, together with the public health significance of pasture contamination with lead, in the United Kingdom.Current regulations in the control of lead poisoning outbreaks are given. The history of lead poisoning of swans by anglers' weights is described together with the successful outcome.The Centre investigated other poisonings including local occurrences of copper toxicity in sheep, the uptake of I 125 by swans, industrial fluorosis and molybdenosis of cattle and there were trace element enquiries related to the use of land reclaimed by infilling with pulverised fuel ash. The poisoning of wildlife was also a province of the Centre. It was involved in national investigations of aflatoxicosis in cattle and guinea pigs, ergotism and "ryegrass staggers" of sheep, bovine botulism and haemolytic anaemia of ruminants due to excessive feeding of Brassicae sp. fodder.The past success of veterinary diagnostic laboratories, and their future, are discussed in view of the impending changes in the control of residues in animal pxoducts. Their role as a tocsin in cases of chemical contamination is illustrated

FTIR studies on the effect of concentration of polyethylene glycol on polimerization of Shellac

© Published under licence by IOP Publishing Ltd. In the present paper, it was reported the FTIR studies on the efect of polyethylene glycol on polimerization of shellac. The shellac was shellac waxfree, and the solvent was ethanol 96%. The shellac films were were prepared by solvent- evaporation method. The concentrations of polyethylene glycol having molecular weight of 400 were 10, 30, 60, and 90 w/w %. Three peak intensity bands of C= O stretching of ester at 1709 cm-1, O-H stretching of hydroxyl group at 3400 cm-1, and C-H stretching vibration at 2942 cm-1 were observed and related to polimerization of shellac. It was found that polymerization of shellac was slowed down by polyethyelene glycol, and the degree of polymerization of shellac decreased with increasing the concentration of polyethyelene glycol

Antimicrobial, starch based barrier coatings prepared using mixed silver/sodium exchanged bentonite

The effect of silver nitrate concentration, pre-washed bentonite (to remove extraneous salt) and back-exchange procedures have been explored to assess the type of silver species formed and their behaviour upon exposure to further salts. X-ray fluorescence was used to quantify the amount of silver present and whether in cation exchange sites, whereas X-ray diffraction and transmission electron microscopy identified the silver compounds present. A further objective was to assess the antimicrobial, barrier and dispersion properties of the silver/sodium bentonites when incorporated into a starch-plasticiser-clay coating used for packaging. The silver/sodium bentonites demonstrated very strong antimicrobial activity towards Escherichia coli, Kocuria rhizophila and Aspergillus niger. Incorporating just 0.03 wt% of silver/sodium bentonite in the coating (0.2 μmol/m2 Ag in dried coating with thickness of 14 μm) produced a > 4.4 log reduction against an initial loading of 2.1 × 105 CFU/object for E. coli. Water vapour barrier properties of coatings prepared on paper and containing the mixed silver/sodium bentonite were unaffected since water vapour transmission rate values of ~20–40 g/m2.day (23°C, 50% relative humidity) were maintained. Also the presence of silver did not adversely affect the clay dispersion. The Ag+ release profile from mixed silver/sodium clay upon addition of HNO3 and NaNO3 is discussed

An indirect Raman spectroscopy method for the quantitative measurement of respirable crystalline silica collected on filters inside respiratory equipment

This article describes the development of an analytical method to measure respirable crystalline silica (RCS) collected on filters by a miniature sampler placed behind respirators worn by workers to evaluate their ‘true’ exposure. Test samples were prepared by aerosolising a calibration powder (Quin B) and by pipetting aliquots from suspensions of bulk material (NIST 1878a and Quin B) onto filters. Samples of aerosolised RCS collected onto polyvinyl chloride PVC filters were ashed and their residue was suspended in isopropanol and filtered into a 10 mm diameter area onto silver filters. Samples were also collected by the Health and Safety Executive's (HSE) miniature sampler from within the facepiece of a respirator on a breathing manikin during a simulated work activity. Results obtained using Raman spectroscopy were compared with X-ray diffraction (XRD) measurements, which was used as a reference method and a linear relationship was obtained. Raman has similar estimates of uncertainty when compared with the XRD methods over the measurement range from 5 to 50 mg and obtained the lowest limit of detection (LOD) of 0.26 mg when compared with XRD and Fourier Transform Infrared FTIR methods. A significant intercept and slope coefficient greatly influenced the higher LOD for indirect XRD method. The level of precision and low LOD for Raman spectroscopy will potentially enable workplace measurements at lower concentrations below the Workplace Exposure Limit (WEL) than are achieved using current analytical instrumentation. Different inward leakage ratio (ILR) measurement approaches were compared using six aerosolised sandstone dust tests. For the three highest inward leakage ratios the Portacount® obtained higher values than the RCS mass or the miniWRAS ratios, the latter of which reporting both particle number and quartz mass concentration. However, these limited ILR data were insufficient to establish statistical correlations between the measurement methods

Thermo-analytical and spectroscopic characterisation of pore lining minerals in reservoir rocks.

Two methods have been developed for the characterisation of sandstone and carbonate based hydrocarbon reservoir rocks. Particular emphasis has been directed towards determining the surface mineralogy in order to understand the flow of fluids through rocks.The first method employs Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) to distinguish the constituent minerals of a reservoir rock using characteristic bands in their vibrational spectra. Spectra collected from reservoir rocks that have undergone various sample preparations have shown that the spectra are weighted to the surface mineralogy. Spectra that are specific to the surface mineralogy have been obtained by sedimentation and ultrasonication techniques. The feasibility of applying partial least squares (PLS) modelling to DRIFTS spectra of reservoir rocks for quantitative analysis has been discussed. Application of PLS modelling to mixtures of powdered mineral standards has shown that it is possible to estimate the mineral constituents. The second method uses organic molecules as chemical probes to elucidate the surface mineralogy of reservoir rocks. Clay mineral standards which have been exposed to certain chemical probes and subsequently heated show desorption profiles (monitored by thermogravimetric analysis (TGA)) that are characteristic for each mineral. The most suitable chemical probe studied so far is Dimethylformamide (DMF). The desorption profiles of DMF from Mg, Ca, Na and K exchanged montmorillonites are characteristic for each of the clays. Characteristic desorption maxima are observed at 420, 330, 220, 190°C, respectively. The desorption of DMF from Mg-SWy-2 within a powdered mixture of mineral standards can only be detected at the 5% level using TGA, whereas using infrared or mass spectrometry 2% can easily be detected with considerable scope for detecting smaller levels.Extensive studies using Variable Temperature-DRIFTS and Variable Temperature x-ray diffraction on the complexes formed between both DMF and N-Methylformamide (NMF), and, Mg, Ca, Na and K-montmorillonites have shown that molecules retained at higher temperatures are located in the interlayer space and are associated with exchangeable cations via their carbonyl groups. Two layers of DMF and NMF are present in the interlayers at low temperatures which reduces to one upon heating to 50-170°C. NMF is found to be present in hydrogen-bonded clusters

Revitalising Collyweston limestone slate production by artificial freeze/thaw splitting

Extraction of limestone roofing slate from Collyweston was an industry which was considered extinct by the early 1990′s, with building repairs relying on wholesale recycling of roofing from demolished buildings. Traditionally stone extracted from the mines was exposed to natural cycles of freeze/thaw to facilitate splitting. Work was undertaken over several years to investigate the resources available and whether these could be artificially frozen to produce slates. The work identified a freeze/thaw regime which could be used to produce roofing slates for historic buildings and which were used in the Historic England restoration of Apethorpe Palace. Mining of the Collyweston limestone stone has now resumed and uses artificial freezing to achieve production of slates which is economically feasible due to the faster process time

An investigation to establish the source of the Roman lime mortars used in Wallsend, UK

This paper presents the results of analytical work which aimed to explore potential sources for the lime mortar used in the Hadrianic fort baths and a third-century repair to Hadrian's Wall at Wallsend, UK. It is generally assumed that quick lime for mortar is produced close to the source, however, as yet, no archaeological evidence of kilns has been found in the Wallsend area. After extensive analysis the mortars were found to be very different in characteristics and suggest variable sources for the quarried limestone and for the aggregates used to manufacture the mortar. Precedence exists in other locations for quicklime to be sourced from kilns set at some considerable distance from Roman construction sites. It is only at Housesteads and Vindolanda, sited close to Carboniferous Limestone outcrops, that Roman lime kilns have been discovered to date. Therefore the investigation included a number of potential sources in the vicinity of Housesteads as well as Permian limestones at Trow Point which is geographically the closest source of limestone. Results suggest that Carboniferous limestone was the most likely source for some of the mortars analysed which may suggest that areas for lime production are less numerous than previously thought and may even have been concentrated around one area

The effect of polyethylene glycol Mw 400 and 600 on stability of Shellac Waxfree

The effect of polyethylene glycol (PEG) having molecular weight of 400 and 600 on stability of shellac waxfree prepared by solvent-evaporation method was reported in the present paper. The stability of shellac was tested by life under heat at 125 °C for 10,30,90, and 180 minutes. It was found that that stability of shellac decreased with heating time at 125 °C. PEG400 gave the most stable effect of shellac for 30 minutes of heating, whereas at 90 minutes and above PEG600 gave the most effect of shellac stability as shown by insoluble solid test and FTIR. The WVTR showed that water vapour barrier properties of PEG600/shellac was beter than that of PEG400/shellac system

Bentonite-Chitosan composites or beads for lead (Pb) adsorption: Design, preparation, and characterisation

This study investigated the efficiency of mixing bentonite with chitosan via different preparation methods, subsequently the different forms were investigated for their ability to remove Pb(II) ions from solution. The different forms of bentonite-chitosan (Bt-Ch), composites and beads, were prepared via solution blending and precipitation methods, respectively and in the weight ratios of 90%/10%, 70%/30% and 50%/50%. The beads were further subdivided, identified as “beads-A" and “beads-B", and were formed by adding either bentonite suspension or bentonite powder, respectively, to solubilised chitosan solution. The composites and beads were characterised by X-ray fluorescence (XRF), thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and pH at zero point charge. XRF analysis showed a cation exchange mechanism occurred when chitosan was initially mixed with the bentonite. TGA results confirmed that beads contained more chitosan compared to their corresponding weight ratio equivalent composites. XRD results showed that chitosan was intercalated within the interlayer space of the bentonite for Bt-Ch composites and Bt-Ch beads-A and that the interlayer spacings increased with increasing chitosan loading. Though similar amounts of chitosan were present in both Bt-Ch beads-A and beads-B, there were fewer reflection shifts for beads B suggesting less intercalation of chitosan when the bentonite was added as a powder. FTIR spectra from the Bt-Ch composites and beads confirmed the presence of both chitosan and bentonite, and the N[sbnd]H bands of chitosan shifted to lower frequencies demonstrating their involvement in the bonding mechanism of chitosan with bentonite. The experimental adsorption data correlated well with both non-linear Langmuir and Freundlich isotherm models, and in which both chemisorption and physisorption processes played crucial roles. The Langmuir-maximum adsorption capacities of Pb(II) ions for all the analysed Bt-Ch composites and beads was found to range from 42.48 ± 4.22 to 94.60 ± 5.63 mg/g. The amount of chitosan present in the adsorbent and its distribution within or outside the interlayer space of the bentonite was shown to have pronounced effects on the Pb(II) uptake by the different Bt-Ch composites/beads, and although the chitosan greatly enhanced the adsorption of Pb(II) a cation exchange mechanism with the clay was still a dominant process. The adsorption of Pb(II) was also significantly affected by the presence of other multi-competing ions. Moreover, the developed Bt-Ch composites/beads exhibited good potential for re-use after five cycles of regeneration, thus, indicating their potential as cost-effective adsorbents for removal of Pb(II) ions from both drinking and wastewater

Monoclinic-orthorhombic first-order phase transition in K<inf>2</inf>ZnSi<inf>5</inf>O<inf>12</inf>leucite analogue; Transition mechanism and spontaneous strain analysis

Hydrothermally synthesised K2ZnSi5O12 has a polymerized framework structure with the same topology as leucite (KAlSi2O6, tetragonal I41/a), which has two tetrahedrally coordinated Al3+ cations replaced by Zn2+ and Si4+. At 293K it has a cation-ordered framework P21/c monoclinic structure with lattice parameters a = 13.1773(2)A, b = 13.6106(2) A, c = 13.0248(2)A, = 91.6981(9). This structure is isostructural with K2MgSi5O12, the first cation-ordered leucite analogue characterised. With increasing temperature, the P21/c structure transforms reversibly to cation-ordered framework orthorhombic Pbca. This transition takes place over the temperature range 848-863K where both phases coexist; there is an 1.2% increase in unit cell volume between 843K (P21/c) and 868K (Pbca), characteristic of a first-order, displacive, ferroelastic phase transition. Spontaneous strain analysis defines the symmetry- and non-symmetry related changes and shows that the mechanism is weakly first order; the two-phase region is consistent with the mechanism being a strain-related martensitic transition