Arsenic levels in rice evaluated using microwave digestion
17 Mar 2017
Evaluation of the levels of many dangerous compounds in foodstuffs, such as those containing arsenic, benefits from a microwave digestion preparation step.
Arsenic is classified by the EU as a category one carcinogen, which means that it has been shown to cause cancer in humans. Some concerns have been raised recently over arsenic levels in rice. It is not a case of pollution or poor farming techniques here. Arsenic is a naturally occurring soil component, however because rice is grown under flooded conditions soil arsenic is readily taken up and incorporated into rice grains.
The result is arsenic content some 10-20 times higher when compared with other grains. Although not in any way an immediate threat to adults, at least in countries where there is a varied diet, some concerns have been raised about the impact of arsenic levels on babies and children.
When it comes to quantifying amounts of potentially toxic materials in foodstuffs it is obviously crucial that all stages of the operation are carried out to maximum efficacy so that results are reliable, accurate and repeatable. Plus, every sample that is prepared for analysis must be treated identically lest trends or changes are missed.
This is why CEM’s acid digestion preparative instruments are designed and manufactured to such a high standard, because the results of the subsequent analysis, whether it is ICP-OES, ICP-MS, AA or GFAA, are of limited worth if the preparation has not been rigorous and thorough.
In the Discover SP-D CEM have produced the world’s only automated sequential microwave acid digestion system, while their MARS 6 is the most intelligent closed vessel acid digestion system on the market. Closed vessel systems for microwave digestion have clear advantages over open vessel systems: the increased pressure inside the vessel raises the solvent’s boiling point, decreasing digestion times, while preventing loss of volatiles and cross-contamination.
The MARS 6 achieves more and does it faster producing comprehensive digestions for the lowest analytical detection levels. Central to the MARS 6 system is CEM’s One Touch Technology, a combination of touchscreen, sensor and software technologies that simplifies the operational process, reducing it down to a range of pre-programmed methods. The MARS 6 even comes with on-board video training videos, so learning and operation is faster too.
Microwave digestion, using the MARS 6 or the Discover SP-D, is a valuable preparative step for the evaluation of the levels of dangerous compounds such as arsenic in foodstuffs.