UMIST develops fast fluid tester

Scientists have developed a new method of detecting contamination in fluids that is quicker and more sensitive than conventional systems and does not require physical samples to be taken.

The fluids the system could be used to monitor range from fruit juice to pharmaceuticals and engine oil.

Kaiku, a spin-off company of UMIST, said that by using an electrical signal the non-contact system can scan a liquid and produce a report within 30 minutes. Traditionally fluid testing has required a sample to be taken for laboratory analysis, a much longer process.

The company also claims the system is three times more sensitive than existing laboratory-based technologies and can detect contamination at 10 parts per billion.

The costs to business of recalling contaminated products can be immense. So early detection could save manufacturers a great deal of money.

As well as detecting unwanted chemicals the sensors will allow companies to control dosing for chemical treatments, do raw material inspection and check for counterfeit fluids.

Kaiku said it is also developing a similar sensor that scans blood cells. The aim is to detect Down’s Syndrome in an unborn baby by examining a sample of the mother’s blood. Existing tests involve taking a sample of amniotic fluid for testing, which carries a risk of miscarriage. A prototype device is being built and should be ready in three years’ time.

The latest sensor works by sending a high-frequency electrical signal between the two electrodes on the outside of the pipe, and measuring the result, a technique known as impedance spectroscopy. As small compositional differences in a fluid give rise to large shifts in its electrical properties it is possible to determine the exact nature of any contamination using this method.

‘We spent £687,000 developing this technology,’ said Graham Partridge, Kaiku’s chief executive.

‘It operates on the fact that every liquid has its own chemical characteristics. We use an electrical frequency to scan the liquid. It’s scanned once, when it’s known to be correct. When there is a contaminant the characteristics change and that’s what we check for.’

The sensor is due to be launched in July. Field trials were conducted with a fruit juice company in the autumn of 2000 and another firm tested its sugar refinery to check effluent discharges for sugar content.

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