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Isotope markers identify polluters
Volume 28/Number 5/May 1994
Pocket-size pH Tester Automated Processor for Sample Preparation The new 20 Batch Filtration System from Whatman International has been designed to automate sample preparation using Whatman Syringeless Filters. The processor has been developed for use with the three current types of syringeless filter: Autovial, UniPrep and CliniPrep. These are all disposable devices for onestep sample preparation, each available with a choice of filter media. Autovial comprises a 25 mm diameter filter unit in a specially designed barrel housing. Samples are placed in the graduated barrel and filtered directly by depressing the self-sealing plunger. UniPrep and CliniPrep operate by means of a hollow plunger which incorporates the filtration medium in its base. UniPrep is recommended for general laboratory applications whilst the CliniPrep range is intended for the filtration of samples of biological origin. The processor operates by automatically compressing up to 18 Autovials, or up to 24 UniPrep or CliniPrep devices, held in sample stands. The compression rate is adjustable to suit the particulate load and viscosity of each batch of samples, and efficiently assures that all samples in the batch receive exactly the same compression treatment. It also reduces the possibility of membrane damage through applying too much pressure, and reduces user contact with any hazardous substances. For added convenience samples stands are available for use with the processor; and the Autovial stands allow direct filtration into autosampler vials. Further details are available from Whatman International Ltd, Whatman House, St Leonard's Road, Maidstone, Kent ME16 0LS, UK.
Chemically Resistant pH Electrodes pHoenix Electrode Co., Houston, Texas are marketing pH electrodes requiring reduced maintenance whilst giving a longer operating life. The electrodes have outer bodies fabricated from a variety of engineering plastics, including Ryton, chlorinated polyvinyl chloride or polyvinylidene fluoride. The reference gels inside the probes use a proprietory, long-lasting polymeric gel.
Newport Electronics have introduced the new, accurate pocket pH tester, model HHpH1, with replaceable electrode and batteries. These features extend the life of the unit, eliminating the need for disposal when the batteries are exhausted. The pocket pH tester is accurate to 0.1 pH over the 0-14 pH range, and also reads solution temperatures in °C or °F, with no need for a separate thermometer. The built-in automatic temperature compensation (ATC) extends accuracy over a broad solution temperature range of between 0 and 70°C (32-158°F). The HHpH1 pH tester combines all these features with a large 1/2" liquid crystal display in one compact package. It is extremely rugged and portable for indoor and outdoor use.
For further details contact Newport Electronics Ltd., 25 Swannington Road, Broughton Astley, Leicestershire LE9 6TV, UK.
Isotope Markers Identify Polluters By including isotope markers in compounds, Isotag Inc., Sunnyvale, CA has developed a technique to identify the source of environmental pollutants, investigate leaks in underground tanks and pipelines and trace theft of oil and other liquid products. For its adaptation of the non-radioactive marking technique, Isotag won the 1994 International Technology Prize from the Dr Jiirgen Schneider Institute (Darmstadt, Germany). Deuterium is typically used as a marker for organic compounds, by replacing three or more hydrogen atoms on the molecule in a reactor containing heavy water. However, isotopes of carbon and oxygen can also be used. More than 500 isotope-marked compounds are available. The detection limit of the tracers using a combination of gas chromatography and mass spectrometry is about 100 ppb in crude oil and about 20 ppb in refined products. In its first industrial applications outside pharmaceuticals, the tags have been used to identify losses of crude oil during snipping. In this case, the markers cost between 1 and 3¢/bbl of oil. However, in tagging for environmental liability, costs are a fraction of a cent per barrel.
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Pocket-size pH Tester Automated Processor for Sample Preparation The new 20 Batch Filtration System from Whatman International has been designed to automate sample preparation using Whatman Syringeless Filters. The processor has been developed for use with the three current types of syringeless filter: Autovial, UniPrep and CliniPrep. These are all disposable devices for onestep sample preparation, each available with a choice of filter media. Autovial comprises a 25 mm diameter filter unit in a specially designed barrel housing. Samples are placed in the graduated barrel and filtered directly by depressing the self-sealing plunger. UniPrep and CliniPrep operate by means of a hollow plunger which incorporates the filtration medium in its base. UniPrep is recommended for general laboratory applications whilst the CliniPrep range is intended for the filtration of samples of biological origin. The processor operates by automatically compressing up to 18 Autovials, or up to 24 UniPrep or CliniPrep devices, held in sample stands. The compression rate is adjustable to suit the particulate load and viscosity of each batch of samples, and efficiently assures that all samples in the batch receive exactly the same compression treatment. It also reduces the possibility of membrane damage through applying too much pressure, and reduces user contact with any hazardous substances. For added convenience samples stands are available for use with the processor; and the Autovial stands allow direct filtration into autosampler vials. Further details are available from Whatman International Ltd, Whatman House, St Leonard's Road, Maidstone, Kent ME16 0LS, UK.
Chemically Resistant pH Electrodes pHoenix Electrode Co., Houston, Texas are marketing pH electrodes requiring reduced maintenance whilst giving a longer operating life. The electrodes have outer bodies fabricated from a variety of engineering plastics, including Ryton, chlorinated polyvinyl chloride or polyvinylidene fluoride. The reference gels inside the probes use a proprietory, long-lasting polymeric gel.
Newport Electronics have introduced the new, accurate pocket pH tester, model HHpH1, with replaceable electrode and batteries. These features extend the life of the unit, eliminating the need for disposal when the batteries are exhausted. The pocket pH tester is accurate to 0.1 pH over the 0-14 pH range, and also reads solution temperatures in °C or °F, with no need for a separate thermometer. The built-in automatic temperature compensation (ATC) extends accuracy over a broad solution temperature range of between 0 and 70°C (32-158°F). The HHpH1 pH tester combines all these features with a large 1/2" liquid crystal display in one compact package. It is extremely rugged and portable for indoor and outdoor use.
For further details contact Newport Electronics Ltd., 25 Swannington Road, Broughton Astley, Leicestershire LE9 6TV, UK.
Isotope Markers Identify Polluters By including isotope markers in compounds, Isotag Inc., Sunnyvale, CA has developed a technique to identify the source of environmental pollutants, investigate leaks in underground tanks and pipelines and trace theft of oil and other liquid products. For its adaptation of the non-radioactive marking technique, Isotag won the 1994 International Technology Prize from the Dr Jiirgen Schneider Institute (Darmstadt, Germany). Deuterium is typically used as a marker for organic compounds, by replacing three or more hydrogen atoms on the molecule in a reactor containing heavy water. However, isotopes of carbon and oxygen can also be used. More than 500 isotope-marked compounds are available. The detection limit of the tracers using a combination of gas chromatography and mass spectrometry is about 100 ppb in crude oil and about 20 ppb in refined products. In its first industrial applications outside pharmaceuticals, the tags have been used to identify losses of crude oil during snipping. In this case, the markers cost between 1 and 3¢/bbl of oil. However, in tagging for environmental liability, costs are a fraction of a cent per barrel.
337