The Tipping Point
John Quick is Principal Scientist at ALS in Coventry, UK. He has more than 25 years experience in the analysis of trace level organic compounds through working for the Environment Agency, Severn Trent Water and ALS.
I have come to the view that we have arrived at a significant tipping point in trace level analysis of organics, where many manual procedures are now ripe to be automated.
We are at this interesting position due to the coming together of two sets of technological innovations:
- The introduction, by Agilent Technologies of the High Efficiency Source (HES) as an option for both the 7010 GC-Triple Quadrupole and the 5977 GC-Single Quadrupole Mass Spectrometers. This offers a set-up in sensitivity and enables us to work with smaller initial samples and to miniaturise our extractions, while still achieving ppt limits of detection.
- The development of a complete range of tools for sample prep automation from both GERSTEL and Anatune, that support miniaturised sample preparation of both liquid-liquid and solid phase extractions at a scale that matches the sensitivity improvements of the latest GC-Mass Spectrometers.
The first innovation means we are now able to design methods that work with 40ml samples; for our customers and the people that take the samples, it is much more convenient to collect, transport and store these smaller samples, compared to the 1 litre samples we have needed in the past.
The second innovation means that, with these new smaller samples, sample preparation can now be automated with instrumentation that is readily available at a reasonable cost.
There are many advantages to adopting this approach:
- Operating costs – in addition to convenience, the costs of transporting and storing these smaller samples is much lower.
- Labour costs – are significantly reduced.
- Data quality – is likely to be better as automation improves reproducibility. It becomes economic to use isotopically labelled surrogates, which improves data quality still further.
- Better blanks – for some determinands, it is the difficulty of obtaining blanks that controls the limits of detection (Naphthalene is a prime example). By eliminating evaporation steps and because it is possible to thermally clean the miniaturised glassware in a furnace, contamination from the surroundings can be reduced.
- Health and Safety – we reduce the amounts of harmful materials used and greatly reduce the analysts exposure to them.
I have had special interest in the analysis of trace organics by GC-MS for a long time and I sense that we are at the stage where the automation of sample preparation for GC-MS will now become the norm.