2014 Microwave Digester Survey Results

Microwave-acid digestion is a common sample preparation step for atomic absorption, atomic emission, or inductively coupled plasma analysis of metals. Microwave digestion takes minutes, compared with hours for conventional hot plate digestion. Because it uses high temperature and strong acids—commonly nitric and hydrofluoric—microwave digestion mineralizes any matrix. For example, EPA method 3052, based on microwave, provides total metal analysis from soil, sediments, sludge, oils, plastics, and biological materials. 

By Trevor Henderson

Top 5 Questions You Should Ask When Buying a Microwave Digester

  1. What is the system’s maximum microwave power output? Microwave energy heats substances quickly to high temperatures. The higher the temperature, the faster and more completely substances are digested. Extractions also need sufficient power, as some solvents can act as a heat sink and are difficult to heat.
  2. Can the system monitor and control every vessel? Temperature and pressure monitoring and control are extremely important. Inadequate safeguards can result in damaged vessels and equipment, and a lack of temperature and pressure control can pose a safety hazard to lab personnel.
  3. How many samples can be processed per run? Though the number of samples processed is dependent upon your laboratory’s needs, planning for growth is always a good idea.
  4. Does the company offer free applications support? Do they offer dedicated, direct service support and local factory-trained field service technicians? Dependable applications and service support are essential since you never know what may go wrong.
  5. How user-friendly is the system? As with many instruments, if a system is very complicated to operate, it generally becomes either a glorified shelf to store things on or a headache to those having to operate it. The easier a microwave system is to use, the better off you will be. Also make sure the vessels are easy to handle and set up.

Acid types used in microwave digestion as reported by survey respondents:

Hydrochloric Acid 22%
Nitric Acid 34%
Sulfuric Acid 15%
Hydrofluoric acid 15%
Perchloric Acid 4%
Phosphoric Acid 4%
Borofluoric Acid 2%
Other 5%

Microwave digestion applications as reported by survey respondents:

Trace metal analysis 24%
Analyzing metals 19%
Material analysis 12%
Soil analysis 9%
Biological sample analysis 9%
Other 6%
Agri-waste analysis 6%
Oil and lubricant analysis 4%

Nearly 21% of respondents plan on purchasing a new microwave digester in the next year. The reasons for these purchases are as follows:

Addition of a new system (increasing capacity)
Replacement of an aging microwave digester
First time purchase
Setting up a new lab

Top 10 features/factors respondents look for when purchasing a microwave digester:

High Durability 92%
Service and Support 92%
Price 88%
Speed of Heating 88%
Intuitive Controls and Software 86%
Small Footprint 86%
Low Maintenance 85%
Short Cool Down Time 77%
Vendor Reputation 71%
Large Capacity 68%

For more information on microwave digesters, including useful articles and a list of manufacturers, visit www.labmanager.com/microwave

See the most recent survey results here

Categories: Surveys

Published In

Designing for Science Magazine Issue Cover
Designing for Science

Published: July 10, 2014

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Designing for Science

When executive director Graham Shimmield and his colleagues set out to build a new home for Bigelow Laboratory for Ocean Sciences in 2009, they wanted a structure sensitive to the surroundings of the new locale on the coast of Maine. With the help of their architects, contractors, and engineers, they got just that.

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