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Biomedical subjects

M D Osselton

Publications and source records attributed to M D Osselton.

At least 19 recordsLinked to original sources
PubMed1992

Retention reproducibility of basic drugs in high-performance liquid chromatography on a silica column with a methanol-high-pH buffer eluent. Changes in selectivity with the age of the stationary phase.

The long-term reproducibility of the separation of basic drugs by high-performance liquid chromatography using a silica column with a methanol-high-pH eluent was examined. The relative capacity factors of specific tertiary amines changed systematically compared with the other drugs on storage of the columns for 1 year. The changes were enhanced on storing the column in mobile phase and were accelerated by prolonged washing with water. A comparison of freshly packed columns suggested that similar changes also occurred with the dry silica on storage. These effects may be a contributor to previously observed batch-to-batch differences in the silica.

Caffeine↗
PubMed1991

The response of evidential breath alcohol testing instruments with subjects exposed to organic solvents and gases. I. Toluene, 1,1,1-trichloroethane and butane.

Experimental work has been undertaken to investigate the potential interference of toluene, 1,1,1-trichloroethane and butane with the evidential breath alcohol testing instruments used in Great Britain (Lion Intoximeter 3000 and Camic Breath Analyser). Volunteers inhaled the volatile substances in an exposure chamber for up to 4 hours, at concentrations of 100, 350 and 600ppm respectively. Subsequently breath was tested on leaving the chamber. No interference was observed with the breath alcohol instruments when the subjects were exposed to toluene and 1,1,1-trichloroethane. A short-term response immediately after exposure was observed for subjects exposed to butane. Further analytical work involving blood and breath samples demonstrated that all three volatile substances were absorbed during exposure and were detectable in blood for at least 3 hours post-exposure. Their elimination post-exposure followed an exponential decay.

Adult↗
PubMed1991

The response of evidential breath alcohol testing instruments with subjects exposed to organic solvents and gases. II. White spirit and nonane.

Following exposure to white spirit vapour, the effect of the expired solvent on evidential breath alcohol equipment was investigated under controlled exposure chamber conditions and in a simulated painting exercise. Five volunteers inhaled the solvent in an exposure chamber at a concentration of 100ppm for periods up to 4h 17min. Two other volunteers were exposed to white spirit while painting with domestic gloss paint in an unventilated room under which conditions exposure concentrations reached 185ppm for 20min. Following all white spirit exposures, volunteers underwent breath tests with the Lion Intoximeter 3000. In all instances the apparent alcohol responses were very small and never exceeded a reading of 1 microgram/100ml for breath samples more than 10min post-exposure. Simultaneous analytical work was conducted to demonstrate that white spirit was absorbed during exposure and was present in the breath and blood after the volunteers had left the exposure atmospheres. A further study involved the exposure of a volunteer to nonane vapour at 100ppm, demonstrating that this compound, being one of the principal components of white spirit, appears to be a good model for studying the uptake and elimination of white spirit.

Adult↗
PubMed1991

The response of evidential breath alcohol testing instruments with subjects exposed to organic solvents and gases. III. White spirit exposure during domestic painting.

The concentration of white spirit vapour in the breathing zone of a volunteer engaged in domestic painting activities has been investigated. Air was continuously sampled and analysed using an infra-red gas analyser (Miran) during painting experiments. Both indoor and outdoor painting tasks were undertaken using commercial paints in a wide variety of situations. For each task the time weighted average (TWA) exposure has been determined. In no case did the TWA exposure exceed the Occupational Exposure Limit-Long Term Exposure Limit (OEL-LTEL) of 100 ppm. The results have been used to discuss the significance of previous studies in which volunteers were exposed to white spirit vapour in an exposure chamber to test for possible interference in breath alcohol testing.

Breath Tests↗
PubMed1991

Study into the ability of patients with impaired lung function to use breath alcohol testing devices.

A subject who fails to provide an adequate breath sample for a breath alcohol measuring device under the provisions of Road Traffic Act 1988 may be charged with refusing to supply a sample unless the police officer believes the person is genuinely unable to do so. Subjects who are confronted with this situation may approach their general practitioner or chest physician for advice on whether they are medically able to provide adequate breath samples to satisfy the breath testing devices. There is currently no guidance available for medical practitioners concerning respiratory performance or lung function which will impair the use of such breath testing devices. This paper describes experiments with human volunteers suffering from respiratory illnesses and their ability to provide adequate breath samples to satisfy the requirements of the breath alcohol testing devices used in Great Britain. It was found that the most suitable parameters for determining whether a subject was capable of using a breath alcohol testing device were spirometry measurements of Forced Expired Volume in one second (FEV1) and Forced Vital Capacity (FVC). In this study subjects with a FEV1 less than 2.0 litres and a FVC less than 2.6 litres were generally unable to use all the devices.

Adolescent↗
PubMed1991

The effect of salbutamol on breath alcohol testing in asthmatics.

Subjects suffering from asthma can occasionally experience difficulty in providing adequate breath samples for evidential breath alcohol testing devices and may therefore resort to the use of bronchodilators such as salbutamol to improve their respiration. Experiments showed that although salbutamol caused bronchodilation it did not affect breath alcohol levels of asthmatics who have been drinking. The blood:breath alcohol ratios obtained from asthmatics were within the normally recorded range before and after use of salbutamol. We conclude that the use of salbutamol by asthmatics does not affect the reliability of measurements made by evidential breath alcohol testing devices.

Adult↗
PubMed1990

The effect of respiratory aerosol inhalers and nasal sprays on breath alcohol testing devices used in Great Britain.

Subjects suffering from respiratory diseases occasionally experience difficulty when attempting to provide breath samples to satisfy the requirements of breath alcohol testing devices. In order to assist ventilation, such subjects may resort to the use of an aerosol inhaler. Twenty aerosol inhalers containing drugs which exhibit an effect on the respiratory system and five nasal sprays used to relieve the symptoms of hay fever, have been tested for interference on the range of breath alcohol measuring devices used by the police in Great Britain. No interference attributable to the contents of any of the aerosol inhalers or nasal sprays tested was observed on any of the instruments in police use.

Administration, Inhalation↗
PubMed1989

International collaborative study of the retention reproducibility of basic drugs in high-performance liquid chromatography on a silica column with a methanol-ammonium nitrate eluent.

An international collaborative study between 10 laboratories has been carried out to study the reproducibility of the separation of basic drugs on silica columns. The laboratories used common solutions of drugs on both a common batch of packing material and different batches of the same brand of packing material. These were also compared with separations on other brands of packing material. Variations within-batch, within-brand and between brands have been compared. The retentions of the drugs were compared using retention times, capacity factors and relative capacity factors compared with an internal standard. The last method was found to give the most reproducible results. Considerable variations were found between the different brands of silica with a smaller variation between the batches of a single silica brand. However, unlike earlier studies, significant variations were found for separations on a single batch of silica which were partly attributed to differences in eluent preparation and column temperature.

Chromatography, High Pressure Liquid↗
PubMed1988

Retention reproducibility of basic drugs in high-performance liquid chromatography on a silica column with a methanol-ammonium nitrate eluent. Batch-to-batch reproducibility of the stationary phase.

The effect of changing the brand and batches of the silica stationary phase used with a methanol-aqueous ammonium nitrate eluent for the high-performance liquid chromatographic separation of basic drugs has been studied. Considerable care had to be taken to obtain a reproducible eluent and the effect of small changes in the concentration of the ammonia solution were examined closely. Large differences in both the capacity factor and relative capacity factors were found for separations on columns packed with four different brands of silica. Significant differences were also observed with columns containing eighteen different batches of Spherisorb S5W, which had been manufactured over a period of several years.

Chromatography, High Pressure Liquid↗
PubMed1988

Collection of analytical data for benzodiazepines and benzophenones.

On April 1st, 1986, amendments were made to Schedule 2 to the Misuse of Drugs Act 1971 such that 33 benzodiazepines became controlled as Class C drugs in the U.K. An analytical database has been prepared to aid the detection and identification of controlled benzodiazepines. Chromatographic properties have been measured including gas chromatography (GC) retention index values, high-performance liquid chromatography (HPLC) capacity factors and thin-layer chromatography (TLC) RF x 100 values. UV spectroscopic and mass spectrometric (MS) data have also been recorded. Analytical data (GC, TLC and MS) are also presented for benzophenones which were produced by acid hydrolysis of the parent benzodiazepines.

Benzodiazepines↗
PubMed1987

Retention reproducibility of basic drugs in high-performance liquid chromatography on a silica column with a methanol-ammonium nitrate eluent. The effect of the mobile phase and the operating conditions.

The reproducibility of capacity factors and relative capacity factors are compared as methods for recording retentions for the high-performance liquid chromatography of basic drugs on a silica column with methanol-aqueous ammonium nitrate as the eluent. The effects of changing the column temperature and the ionic strength, pH and proportion of organic modifier in the eluent on the retentions and selectivity have been studied. The results suggest that the mobile phase and operating conditions must be closely defined in order to obtain results of adequate reproducibility to develop a data base of retention values for interlaboratory comparisons and/or for the identification of basic drugs.

Chemical Phenomena↗
PubMed1987

Retention reproducibility of basic drugs in high-performance liquid chromatography on a silica column with a methanol-ammonium nitrate eluent. Interlaboratory collaborative study.

The reproducibility of the separation of basic drugs on silica columns has been tested in a collaborative study between nine laboratories. The results from the different laboratories were very similar. Various methods of recording the retention properties of the drugs were compared with reference to their reproducibility and ability to discriminate between different compounds. Relative retention times, relative capacity factors, and corrected capacity factors were much better than retention times and capacity factors, although all the methods suffered from large errors with weakly retained compounds. All the work was carried out using a single batch of silica to avoid variations due to the stationary phase.

Ammonia↗
PubMed1986

Chromatographic identification of pesticides.

The chromatographic properties of 51 common pesticides have been measured using seven different chromatographic systems involving gas-liquid chromatography (GLC), high-performance liquid chromatography (HPLC) with diode-array spectrophotometric detection and thin-layer chromatography (TLC) with different spray reagents. Correlation coefficients were calculated for combinations of all systems. The best combination of the chromatographic systems examined for the identification of an unknown compound is GLC on OV-17, HPLC on ODS-Hypersil with acetonitrile-water as eluent and TLC using an isooctane-ethyl acetate solvent system.

Chromatography, Gas↗
PubMed1984

Poisoning-associated deaths for England and Wales between 1973 and 1980.

The annual number of deaths in England and Wales associated with poisoning by solids and liquids over the 8-year period between 1973 and 1980 has remained fairly constant with an average of 2897. Marked trends in the number of deaths associated with specific drugs are evident and apparently reflect prescription trends and drug availability. Barbiturate poisonings dropped steadily following the downward trend in barbiturate prescriptions. Deaths associated with dextropropoxyphene, paracetamol and certain benzodiazepines increased dramatically.

Analgesics↗
PubMed1980

Gas--liquid chromatographic retention indices of 296 non-drug substances on SE-30 or OV-1 likely to be encountered in toxicological analyses.

The advent of the widespread use of selective detectors (electron capture detector, phosphorus/nitrogen dectector) for gas--liquid chromatography used in toxicological analyses has revealed the presence of hitherto unseen interfering materials. These substances may be conveniently grouped into (1), anti-oxidants; (2), putrefactive and endogenous compounds; (3), pesticides; (4), food additives, flavours and fragrances; (5) plasticisers, plastic additives and vulcanising agents and (6), scintillation reagents. To facilitate the identification of these materials, retention indices on the dimethyl silicone phases SE-30 or OV-1 have been compiled by the two laboratories to include 296 such compounds. Most gave single peaks, but some gave complex patterns indicating that they were mixtures of compounds. Of the 296 compounds, 14 did not give observable peaks, 8 gave 2 or 3 peaks and 44 gave more than 3 peaks. To determine the interlaboratory difference between retention index measurements, 17 compounds were chromatographed by both laboratories: the mean difference was +/- 13 retention index units with only one greater than +/- 50 retention index units. Examples of how these materials may be encountered during toxicological analyses are given. Data are also presented on compounds which have been used as internal standards.

Chromatography, Gas↗