Fast, clean and precise sample preparation for trace metal analysis in environmental samples

As ever more stringent environmental regulations drive the rise in demand for trace metal analysis in environmental labs, the need to measure at ever lower levels has also increased. This has lead to ICP-MS technology becoming more ubiquitous for environmental analysis and therefore extra significance on sample preparation methods.

Hot-block and closed vessel microwave digestion are two recognised, conventional methods. Hot block digestions tend to be very long-winded, and often has low digestion quality, as well as disappointing levels of volatile compound recovery. However, closed vessel microwave digestion is widely recognised as an effective technique with quick and complete digestions, cleaner operation and complete recovery of volatile compounds and has been included in various international norms including US EPA methods.

Analytix has recently published a technical paper that compares the recovery of 3 certified reference environmental materials using a high pressure 15-place rotor, and a medium pressure 44-place rotor with a Milestone Ethos UP microwave digestion system. This system uses a contactless, temperature sensor for both rotors - and the 15-place rotor also took advantage of Milestone’s patented ‘vent and reseal’ technology to control the internal pressure of each vessel.

The results displayed a full recovery of the elements detailed in the material reference certificates along with low relative standard deviations (RSDs). This data shows that the Ethos UP is totally compliant with the US EPA methods for environmental samples using both rotor systems. Moreover, the digestions were completed in a fraction of the time in comparison to the hot-block method and used considerably less acids.