Margot Baird

The study of pressure delivery for hypertrophic scar treatment

Pressure garments have been used prophylactically and to treat hypertrophic scars, resulting from serious burns, since the early 1970s. They are custom‐made from elastic fabrics by commercial producers and occupational therapists. However, no clear scientifically established method has ever been published for their manufacture from powernet fabrics. The earlier work identified the most commonly used fabrics and construction methods for the production of pressure garments by occupational therapists in UK burn units. These methods have now been evaluated by measuring the pressures delivered to both cylinder models and to human limbs using I‐scan® pressure sensors. The effect of cylinder/limb circumference and the effects of the fabric and reduction factor used in pressure garment construction on pressures exerted have now been established. These measurements confirm the limitations of current pressure garment construction methods used in UK hospitals. These results were also used to evaluate the Laplace law for the prediction of interface pressures.

Separation and determination of oligomers and homologues of aliphatic alcohol ethoxylates in textile lubricants and lubricant emulsion by high-performance liquid chromatography

Abstract Homologous mixtures of 3,5-dinitrobenzenoates of aliphatic alcohol ethoxylates (AEs) were separated by high-performance liquid chromatography (HPLC) with high resolution using an amino bonded silica column and gradient elution of ternary solvents (hexane-dichloromethane-methanol). When the method was combined with novel sample clean-up and extraction procedures, oligomers of AEs in textile lubricants and a lubricant emulsion were satisfactorily determined with recoveries 75% and good reproducibility. A reversed-phase HPLC method was also developed to characterise the alkyl groups of AEs.

Determination of poly(ethylene glycol)s by both normal-phase and reversed-phase modes of high-performance liquid chromatography

Abstract A normal-phase HPLC system using an amino column has been developed to characterise oligomers of poly(ethylene glycol)s (PEGs) of average M r 400 to 2000 with derivatisation by dinitrobenzoate. Normal-phase HPLC with gradient elution using ternary solvents of hexane, dichloromethane and methanol has produced a baseline resolution for oligomers of PEG 400, 600 and 1000, while PEG 1000 and 2000 were analysed by using binary solvents of acetonitrile and water. Mixtures of PEGs have been determined by these HPLC systems. PEG 400 in a textile finish has also been determined with satisfactory recovery. It has been found that the hydroxyl group of solvents in normal-phase HPLC plays an important role in resolution and retention of PEG oligomers. Derivatisation efficiency for PEGs by dinitrobenzoyl chloride and quantitative determination of derivatised PEGs by HPLC have been studied. A reversed-phase (RP) mode of HPLC was examined for determination of PEG 400 oligomers. The normal-phase system provided greater resolution for oligomers of PEGs.

Separation of broadly distributed nonylphenol ethoxylates and determination of ethylene oxide oligomers in textile lubricants and emulsions by high-performance liquid chromatography

A simple and rapid high-performance liquid chromatography method is described for separation and determination of ethoxylated nonylphenols. By using an amino bonded silica column with an acetonitrile-water gradient, the oligomers of ethoxylated nonylphenols with an average of 6 EO (ethylene oxide number) up to 40 EO were separated with satisfactory resolution. It was found that the partition of solutes between the stationary and mobile phases, and hydrogen bonding between solutes, solid-phase amino groups, water and acetonitrile were the main factors governing separation. The recoveries of total oligomers of nonylphenol-8 EO from a mixed emulsion with mineral oil, methyl oleate, peanut oil and the textile lubricant Blend 1 were 90.0±10.2, 95.6±7.9, 90.0±9.5 and 107.2±11.4%, respectively. The application of this method can be extended to determine non-ionic surfactants in other matrices.

The Study of Pressure Delivery for Hypertrophic Scar Treatment

Pressure garments made from elastic fabrics are commonly used to treat hypertrophic scars. Occupational Therapists in the UK hospitals do not commonly take into account the potential influence of either fabric properties or the body part circumference on the pressures exerted by pressure garments constructed with standard reduction factors. This investigation sought to establish the relationship between the pressures exerted on cylinder models by pressure garments (made from 4 different powernet fabrics) and the circumference of the cylinder model.

The Determination of Alkyl Phenol Ethoxylates in Wool-scouring Effluent

Alkyl phenol ethoxylates (APE0s), particularly nonyl phenol ethoxylates (NPE0s), are non-ionic surfactant components used in woollen-yarn spinning oils and industrial detergents. In recent years, concern over the hormone-disrupting properties of NPEOs has given rise to proposals to ban their use in EU countries. A sensitive and reliable method of detecting NPEOs on incoming raw material and in textile effluent is therefore required. A method has been developed to detect NPEOs at ppm levels in wool-scouring effluent by the application of extraction and clean-up procedures followed by high-performance-liquid-chromatography (HPLC) analysis.