How one man’s ‘eureka moment’ led to the birth of a new industryPosted: September 13, 2012
By Tracey Nicholls
The 1950s were a golden time in our social history. As we left behind the post-war austerity years, there was a new optimism and appetite for experimentation, exploration and reinvention.
It was in this setting that CSIRO’s Alan Walsh had a moment of inspiration that led to one of the 20th century’s most significant achievements in chemical analysis – the development of atomic absorption spectroscopy (AAS).
For years Alan, a tall and wiry Lancashire-born physicist, had been trying to solve a problem that had confounded other scientists for decades. It was the challenge of how to measure small concentrations of metallic elements more exactly through spectroscopy.
On a Sunday morning in March 1952 Walsh was working in his garden when, in one revealing flash of thought, he had the answer. He hurried inside, dirt still on his shoes, and phoned his colleague John Shelton.
Up until that point, the normal procedure in spectroscopy was to vaporize an element and measure the energy emitted as light by its excited atoms.
“Look, John…we’ve been measuring the wrong bloody thing! We should be measuring absorption, not emission!” Alan shouted down the phone line.
Early on Monday morning he set up a simple experiment, using the element sodium, in his laboratory at CSIRO’s Division of Chemical Physics. By morning tea he had a successful result – the basis of what has been called the most significant advance in chemical analysis of the 20th century.
In purely scientific terms it was a remarkable achievement. In subsequent practical use its value has been beyond measure. As AAS allows the measurement of extremely small amounts of elements, it is now routinely used in medicine, manufacturing, mining, environmental monitoring and laboratories throughout the world.
Not only has AAS saved lives and made industry more efficient, but the commercialisation of this technology led to the birth of the scientific instrument industry in Australia—an industry now worth more than $1 billion a year.