Instruments robust enough to survive the treacherous depths of the ocean are being developed by analytical chemists in the US.

Instruments robust enough to survive the treacherous depths of the ocean are being developed by analytical chemists in the US.

Hydrothermal vents in the ocean floor leak hot acidic water and spew out jets of hot brine containing leached minerals at up to 350 ?C. Consequently, the vents - or black smokers - create a harsh environment. These conditions in the deep-sea have made in situ mineral analysis difficult in the past.

Now scientists at Arizona State University and the University of Washington have developed a battery-powered fibre-optic Raman system to perform continuous measurements whilst surviving the severe environment. Mimicking sea-floor conditions, Karl Booksh and his colleagues claim their portable infrared instrumentation achieves low detection limits for sulfates and nitrates, particularly when other common vent fluid plume minerals are added.

Sapphire-ball lenses offer optical materials that are resistant to the corrosive hydrothermal fluids. The field-portable system also features a diode laser, detector and single-board computer, all placed in a pressure container.

They hope the instrumentation can be applied to monitoring industrial and environmental systems.

Carolyn Ackers