Fuller's Earth Research Articles

Treatment of paraquat poisoning in man: methods to prevent absorption.

Theoretically, absorption of an ingested dose of paraquat may be reduced by gastric lavage, induced emesis, whole-gut lavage or by the oral administration of absorbent substances. Animal experiments suggest that paraquat is absorbed poorly from the stomach and absorbed incompletely (less than 5%) from the small intestine over a 1-6 h period. Although gastric lavage would therefore seem a logical way to ameliorate the toxicity of an ingested dose of paraquat, peak plasma concentrations are attained rapidly and evidence for the efficacy of gastric lavage in man is poor. In 1977, a potent emetic (PP796) was added to liquid and solid formulations of paraquat because experiments in primates had demonstrated a fivefold reduction in toxicity. In man, ingestion of formulations containing an emetic is more likely to cause spontaneous vomiting within 30 min than non-emetic preparations. However, definite evidence of benefit, as judged by improved patient prognosis, has yet to be established. Gut lavage has been shown to remove only a small proportion of an ingested dose of paraquat. At the flow rates employed in man (75 ml/min), approximately 0.5-1.0 litres of lavage fluid/h may be absorbed across the intestinal wall. Since there is a theoretical risk of increasing paraquat absorption, the use of whole-gut lavage cannot be recommended. Bipyridilium herbicides are absorbed by soil and clay minerals, and montmorillonite in particular has been shown to be a strong binding agent in vitro. Accordingly, the use of Fuller's Earth (calcium montmorillonite) and Bentonite (sodium montmorillonite) for the treatment of poisoning has been investigated in animal models.(ABSTRACT TRUNCATED AT 250 WORDS)

Specific creatinine determination in laboratory animals using the new enzymatic test kit "Creatinine-PAP".

The new Creatinine-PAP test kit from Boehringer Mannheim GmbH was evaluated for the determination of creatinine in dogs, rabbits, guinea pigs, rats, and mice. In comparison with methods based on the reaction with alkaline picrate, the enzymatic method gave the lowest serum creatinine values. The differences are caused by serum substances (non-creatinine chromogens) reacting with picric acid. Noticeable differences between the standard inulin clearance and creatinine clearance (e. g., in rats) arise because the non-creatinine chromogens interfere differently in the picric acid methods, and serum and urine contain different concentrations of interfering substances. The concentrations of non-creatinine chromogens are different in the various laboratory animals. Since these substances cannot be entirely removed (e. g., in rats, dogs) by the adsorption procedure with Fuller's earth, we recommend the peroxidase-coupled enzymatic test as a practical and specific method for routine measurements of creatinine in laboratory animals.

Intraparticle diffusion process occurring during adsorption of dyestuffs

The adsorption of a dyestuff, Telon Blue (Acid Blue 25) on Fuller's earth and Astrazone Blue onto fired clay has been studied. An intraparticle diffusion rate parameter has been defined characteristic of the rate of diffusion after the early stages of the adsorption. The rate parameter has been determined for a number of variables including adsorbent mass, initial dye concentration, and particle size.

R.H.S. Robertson. Fuller's Earth: A History of Calcium Montmorillonite. Volturna Press, Hythe, England, 1986. 421 pp. Price (including postage) £25 (overseas); £20 (UK); £17.50 (UK members of the Mineralogical Society); £15 (UK multiples of 10 copies)

R.H.S. Robertson. Fuller's Earth: A History of Calcium Montmorillonite. Volturna Press, Hythe, England, 1986. 421 pp. Price (including postage) £25 (overseas); £20 (UK); £17.50 (UK members of the Mineralogical Society); £15 (UK multiples of 10 copies)

Clay mineralogy and plasticity of the Fuller's Earth Formation Bath, UK

AbstractClay from the Fuller's Earth formation is shown to contain mainly illite, kaolinite and calcite, in contrast to the Fuller's Earth Bed in which montmorillonite is the main clay mineral. A negative correlation has been demonstrated between the calcite content and the plasticity as measured by the Atterberg limits. Fresh samples from the Fuller's Earth Bed have a higher plasticity than those of the fuller's earth clay with similar calcite percentages, due to the relative increases in the expanding lattice clay mineral. Weathering of the fuller's earth clay typically reduces the calcite content and increases the percentage of montmorillonite, resulting in a higher plasticity.

ELECTROMAGNETIC SOUNDING OF THE KAPURDI LIGNITE DEPOSIT IN WESTERN RAJASTHAN, INDIA*

ABSTRACTIn the Kapurdi block of the Barmer lignite field in western Rajasthan, India, lignite occurs as a number of discontinuous seams of varying thickness up to a few m. The country rock is a succession of clay, sand and various members of the clay‐sand family. The overburden, comprising sand, Fuller's earth, bentonitic clay, clayey sand/sandy clay and clay, is thick and, electrically, highly conductive. Both its thickness (40–90 m) and conductivity (0.5–1.0 S/m) are highly variable. The lignite seams may occur anywhere in the clay‐sand sequence below this overburden.A ten‐layered electrical model of the Kapurdi area was parameterized on the basis of galvanic resistivity sounding and core drilling results. This model was then validated by electromagnetic sounding measurements made with a 200 × 200 m square loop transmitter and energizing current of variable frequency (80 Hz to 11 kHz), using central induction sounding techniques. With a loop of this size, only formations in the overburden could be mapped. Subsequent computer modeling has shown that a larger loop of size, say, 800 m and a frequency band of 30–500 Hz are required to map formations below–as well as those within–the overburden. Even then only various clay‐sand interfaces can be mapped, i.e., only over‐burden thickness and the likely depth range of lignite seams (if they occur) can be estimated. Direct mapping of lignite seams is not feasible in practice. This is true of loop‐dipole, as well as central induction sounding. It is interesting that skin depth need not always be a factor limiting depth of exploration in electromagnetic prospecting.

Electroosmosis and the determination of ζ potential: The effect of particle concentration

It has recently been demonstrated that the ζ potential of concentrated colloidal dispersions may be determined by measurement of the rate of electroosmosis at colloid occluded membranes. The present paper substantially extends the range of the technique in a study of dispersions of the clays kaolin and Fuller's earth at up to 1000 g liter − solids ( φ p = 0.4). It is found that the effective ζ potential decreases with concentration in both cases, an effect which is especially marked for Fuller's earth. This dependence correlates in a noteworthy manner with the rheological properties of the dispersions. Such measurement of the concentration dependence of ζ potential, which has previously received little attention, may well prove a useful probe for changes in the structure of complex dispersions.

Leucocyte suppression in treatment of 72 patients with paraquat poisoning.

72 patients who had ingested more than 10 ml 20% or 24% liquid paraquat concentrate were treated for 2 weeks with high doses of dexamethasone and cyclophosphamide, forced diuresis with liberal potassium supplements, and, to eliminate paraquat from the gut, Fuller's earth suspension, activated charcoal, and magnesium sulphate. 52 patients (72%) survived. Serum paraquat concentrations were measured retrospectively in samples from 25 patients. 18 had levels of 2-76 mg/l; 6 survived and 12 died. The other survivors were a patient with a serum level of 0.5 mg/l at 24 h and 6 with positive urine tests but no measurable paraquat in serum collected 8-16 h after admission.

Fuller's earth and fired clay as absorbents for dyestuffs external mass transport processes during adsorption

The kinetics of the adsorption of two dyestuffs, Astrazone Blue (Basic Blue 69) and Telon Blue (Acid Blue 25), onto fired clay and Fuller's earth have been studied. The rate of adsorption is controlled initially by the boundary layer film and an external mass transfer coefficient has been determined for this process under the influence of a number of variables including agitation, initial dye concentration, adsorbent particle size, adsorbent mass and temperature.

Fuller's earth and fired clay as adsorbents for dyestuffs

The ability of Fuller's earth to adsorb a basic dye (Astrazone Blue — Basic Blue 69) and an acidic dye (Telon Blue - Acid Blue 25) has been studied. The equilibrium saturation adsorption capacities were 1200 mg dye g−1 Fuller's earth and 220 mg dye g−1 Fuller's earth for Astrazone Blue and Telon Blue, respectively. The kinetics of the adsorption processes were studied in an agitated batch adsorber. The time to reach 90% equilibrium value was achieved in less than 1 h. The variables investigated were agitation, adsorbent mass, initial dye concentration and temperature. A limited number of studies were undertaken using a fired clay but significantly lower saturation capacities were obtained, namely, 7 mg dye g−1 fired clay and 40 mg dye g−1 fired clay for Telon Blue and Astrazone Blue, respectively.

Stratigraphy and sedimentology of the Great Oolite Group in the Humbly Grove Oilfield, Hampshire

The main reservoir of the Humbly Grove Oilfield comprises variably dolomitic grainstones and packstones representing the Bathonian Great Oolite Group. The Bathonian sequence commences in Lower Fuller's Earth claystones which coarsen upwards into oncolitic claystones and skeletal packstones probably equivalent to the Fuller's Earth Rock. Above is a variable succession of wackestones and thin packstones which have a distinctive sandstone at their base. This sequence is named here the Hester's Copse Formation. The succeeding Great Oolite Limestone is predominantly oolitic and cross-bedded on a variety of scales. It exhibits both coarsening and fining sequences which have locally well-developed capping hardgrounds and burrowed horizons. The Great Oolite Limestone is subdivided into three Members: the lowest (the Humbly Grove Member), and the highest (the Herriard Member) begin with massive shoal oolite deposition, but each then pass upward into more interbedded sequences representing a more transgressive environment. The middle member (the Hoddington) is a thin but widely correlatable wackestone. The overlying Forest Marble commences abruptly in claystones, but there is an upward increase in both the incidence and thickness of discrete oolitic limestones. Both the Great Oolite Limestone and Forest Marble were affected by early fresh-water dissolution and cementation in addition to the localized development of submarine cements. The top of the Great Oolite Group is represented by the Cornbrash. The Lower Cornbrash is a thin micritic limestone while the Upper Cornbrash is a calcareous claystone which passes upwards into the Kellaways Clay. The Bathonian sequence overlies the dolomitic limestones of the Inferior Oolite, the Lower Fuller's Earth claystones being interpreted as a basinal marine mudstone sequence, marking a substantial deepening and transgressive phase at the opening of the Bathonian. These mudstones shoal upwards into the quiet, but photic, water deposits of the Fuller's Earth Rock. The Hester's Copse Formation represents the temporary development of wave-dominated terrigenous shoreface and lagoonal conditions. Renewed transgression established a high-energy, tide-dominated, carbonate shelf upon which the Great Oolite Limestone was deposited as a series of shoal oolites, channels, tidal deltas and spill-overs. Periodic exposure of the carbonate sand-bodies led to the production of early dissolutional and cementation fabrics that post-date (and largely obliterate) submarine cements. The Forest Marble opened with a further phase of deepening, and the temporary establishment of muddy facies. Subsequently discrete tide-dominated ridges and linear channelized oolitic sands prograded into the area. The latest Bathonian is marked by subsidence of the carbonate ramp to the south of the London Platform, the Cornbrash-Kellaways Clay sequence accumulating under progressively deepening waters.

Efficacy of activated charcoal and magnesium citrate in the treatment of oral paraquat intoxication

The binding capacity of activated charcoal for paraquat was evaluated in vitro and in vivo and compared with Fuller's earth. In vitro activated charcoal absorbs paraquat and is as effective as Fuller's earth. Activated charcoal's absorbing capacity for paraquat is increased when it is suspended in magnesium citrate and is maximal at pH 7.8. Paraquat (200 mg/kg) administered orally to male mice, followed 30 minutes later by activated charcoal, Fuller's earth (4 gm/kg), and magnesium citrate (0.01 cc/gm) resulted in a survival rate of 31% in the controls, 63% in the activated charcoal and Fuller's earth groups, and 69% in the magnesium citrate group (P values not significant). When activated charcoal was administered concomitantly with magnesium citrate, the survival rate was improved significantly to 94% (P less than 0.01). The efficacy and greater availability of activated charcoal and magnesium citrate make these materials the treatment of choice for gastrointestinal decontamination in oral paraquat poisoning.

Improvement of sea water quality by physical and chemical pre-treatment in a bivalve hatchery

The development to the veliger stage of fertilised ova of the Pacific oyster, Crassostrea gigas, was compared in raw natural sea water and in sea water pre-treated with various substances. Significantly higher veliger yields were obtained when the water was pre-treated with 1 mg l −1 EDTA. Combinations of EDTA and 20 mg l −1 sodium metasilicate, or 20 mg l −1 alumina, or 50 mg l −1 magnesium trisilicate or 150 mg l −1 Fuller's earth also enhanced development.

The IGS Bruton borehole (Somerset, England) and its regional structural significance

The Bruton borehole spudded into the Fuller's Earth Rock and penetrated a relatively thin Mesozoic sequence which rests unconformably on Carboniferous Limestone. Jurassic and Permo-Triassic sediments thicken away from the borehole which is considered to be sited on a `high' in the Palaeozoic `basement'. The presence of `highs' in the Palaeozoic `basement' of this region is thought to be related to the position of major Mesozoic growth faults, to the north of which relatively low subsidence rates gave rise to attenuated Permo-Triassic and Jurassic sequences.

Constitution of tars from the flash pyrolysis of Australian coals: 1. Separation

Separation of the maltene fraction of Millmerran flash-pyrolysis coal tar by ion-exchange and adsorption chromatography produced coal-tar resins, aromatic hydrocarbons (AH) and an alkane/alkene fraction. The coal-tar resins comprise acid, base, neutral and polyfunctional fractions. Derivatives of benzene and naphthalene are the main volatile constituents of the AH fraction, while the alkane/alkene fraction consists mainly of straight-chain hydrocarbons from C 10 to C 34 and small amounts of isoprenoid hydrocarbons, steranes and triterpanes. Fuller's Earth, used in the separation of the maltenes, suffers from the disadvantage of irreversibly adsorbing organic material.

Colorimetric determination of acetaminophen

A colorimetric procedure for the emergency determination of acetaminophen in plasma is described. Acetaminophen is extracted into ethyl acetate at physiological pH to eliminate salicylate, amino acids and other polar compounds. The extract is treated with Fuller's earth to remove bilirubin and with anhydrous sodium sulphate to remove traces of aqueous droplets containing proteins or uric acid. The extract is back-extracted into carbonate and simultaneously treated with Folin--Ciocalteau reagent to produce a stable colour complex.

An attachment to a tractor‐mounted seed‐spacing drill for applying granular formulations to small field‐plots

SUMMARYTractor mounted equipment is needed to deliver granular formulations of pesticides accurately to the soil in small‐plot trials in a manner comparable to commercial equipment. Inexpensive units incorporating a belt unit mechanism were designed and fitted to a Mk II Stanhay S‐870 Precision Seed‐Spacing Drill. The individual delivery belts were driven through a continuously‐variable reduction gearbox by the main drive shaft of the drill and pre‐weighed amounts of granules were placed along the belts. Insecticides and dose patterns could thereby be changed readily from plot to plot.In field assessments of uniform doses of fuller's earth granules delivered to single row, 4·8 and 10·3 m plots, the mean weights recovered were 94–98% of the target doses, S.E.'s being ±2% of the means. When 16‐fold, exponentially‐increasing doses were delivered, the weights recovered were generally within 10% of the target dose at any point within 0·2 m from the start and 0·3 m from the finish of the plot. The performance of uniform doses of carbofuran (on sand) and chlorfenvinphos (on Spanish Silical) against cabbage root fly on radish in 15 m plots showed that errors in loading were insignificant compared with the variability in pest infestation on the field plots. With doses increasing exponentially by c. 12‐fold applied to similar plots, the percentage of carrots or radish undamaged by carrot fly and cabbage root fly increased from 40–60% to 85–99·3%, the relationship between the log‐log proportion of undamaged roots and log‐dose being linear.The equipment allows free‐flowing, granular pesticide products to be applied to small plots of a wide range of row‐crops much more accurately than has hitherto been possible. A work rate of 24 plots h‐1 was achieved by a team of two technicians and a tractor driver.

Novel Composite Sorbent Beads for Paraquat Removal by Hemoperfusion

The present report describes the development and performance of a column that is to be used for removal of paraquat from circulating blood in a hemoperfusion-type set-up. The key element of the system is a newly developed sorbent material containing fuller's earth entrapped in cross-linked agarose beads (Talosit). The technique produces a sorbent material exhibiting a very large active surface area while allowing for high mobility of paraquat molecules within the beads and favorable flow characteristics of packed column. Cross-linking of the agarose (by epichlorohydrin) also has a most beneficial effect on the mechanical strength of the beads as well as on their stability to sterilization in an autoclave. The composite beads exhibit good blood compatibility. A scanning electron microscope analysis of the beads showed no adherence of cellular blood components after contact with blood. Moreover, no significant changes in plasma composition had taken place when the beads were properly conditioned prior to contact with fresh human blood. A comparative study of paraquat removal from saline solution by the new beads and by cellulose-coated activated charcoal (Adsorba-300C) indicates a higher removal rate with the former. The results obtained so far with this new sorbent are very promising and extension of these studies to in vivo hemoperfusion is under way.

Inhibition naturelle des diatomées dans l'eau de mer — étude d'un traitement adsorbant réparateur

The growth of eight planktonic algae was compared in filter or heat-sterilized sea water. The diatoms were inhibited by unheated sea water, with a typical increase of generation time, and a decrease of biomass and chlorophyll synthesis of the cultures. Such inhibition, changing with time and disappearing at 120°C, was removed by treatment of sea water by two adsorbant powders, celite and Fullers's earth. This natural inhibition of diatoms in raw sea water could be due to the presence of thermolabile ectocrines. The aquacultural and ecological involvements of these observations are discussed.

Enzymic assay of creatinine in serum and urine with creatinine iminohydrolase and glutamate dehydrogenase.

We describe an assay for creatinine in which it is converted by creatinine iminohydrolase (EC 3.5.4.21) into ammonia and N-methylhydantoin. The ammonia is subsequently assayed by use of alpha-ketoglutarate and glutamate dehydrogenase (EC 1.4.1.3). Use of NADPH as coenzyme eliminates all interferences from endogenous reactions. Endogenous ammonia in the sample is eliminated during a preincubation. The reaction reaches the endpoint in 15 min at working temperatures of 20-37 degrees C. No sample blank or reagent blank is needed. The standard curve is linear at least to 884 mumol (100 mg) of creatinine per liter. Average analytical recovery of creatinine in serum and urine is 99%. Within-run and between-run CVs are less than or equal to 2% and less than or equal to 6% for creatinine values of 335 mumol/L (38 mg/L) and 80 mumol/L (0 mg/L), respectively. Results by the described method (y) compare well with those by Jaffé's kinetic test (y = 1.01x -- 12.8), Berthelot/AutoAnalyzer method after treatment with immobilized creatinine iminohydrolase (y = 0.987x -- 13.2), Jaffé's test run on the SMA 12/60 (y = 1.011x -- 5.8), the Wahlefeld method (y = 1.014x -- 0.88), and Jaffé's test after deproteinization and absorption on fuller's earth (y = 0.985x -- 3.08). The method may be suitable for discrete, including centrifugal, automation.