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Microwave Sample Prep

Microwave digestion is the preparation method of choice for analyzing metals in complex mixtures.

by Other Author

Microwave digestion is the preparation method of choice for analyzing metals in complex mixtures. Food and environmental industries favor this technique, which is also applicable to testing materials, soil, agricultural waste products, engine oils, and biological samples. Pharmaceutical applications are growing too, as safety-conscious regulators demand trace metal analysis.

Top 5 Questions You Should Ask When Buying a Microwave Sample Preparation System

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.

Recent Trends in Microwave Sample Prep:

• Several vendors have introduced microwave systems that permit loading of multiple samples during each run to improve throughput, as well as to control features.

• Laboratory microwave systems are used mostly for sample preparation. However, microwave-assisted chemical synthesis is an emerging technique that provides many advantages over conventional heating mantles, oil baths, and hot plates.

• Microwave sample preparation occurs in high-pressure vessels that reach up to 300°C and 1500 psi. Despite the harsh conditions, equipment has been trending toward simplicity. Today’s sample holders, for example, use snap-on caps and work with liquid handlers that interface directly with autosamplers for inductively coupled plasma analysis.

• Microwave-assisted sample preparation has come a long way since the 1980s, when systems resembled kitchen appliances more than scientific instruments. Microwave’s ability to dissolve almost any matrix, leaving target metal species behind, provides sample prep capabilities unavailable through other methods.

Recently Released Microwave Sample Prep Products

• Includes One Touch™ Technology, an advanced, intuitive software and sensor design that greatly simplifies the technique
• Features built-in knowledge and training videos
• Developed to make sample preparation for elemental analysis virtually effortless
• As easy to operate as an iPhone
• Reduces system programming to simply selecting a method that matches the sample type


• Features Milestone’s unique SRC technology in a fully automated benchtop package
• Brings greater efficiency to microwave digestion, using disposable glass vials instead of traditional digestion vessels
• Reduces digestion acid volume, lowering digestion blanks
• Results in more complete digestions, and better analytical data quality for ICP-MS analysis
• Digests up to 15 samples—of any matrix—simultaneously


Multiwave PRO Microwave Reaction System
• Serves two groups: professionals in trace analysis and synthetic chemistry
• Masters high temperatures and provides comprehensive safety features
• Wide range of accessories available
• Sustains an output level of 1500 W (IEC 705) over years
• Unpulsed microwave power over the whole range ensures precise control of critical reactions

Anton Paar

Initiator+ Microwave Peptide Synthesizer
• Boasts simple and intuitive software, an integrated computer control system and a large touch screen
• Allows user to drive reactions to as high as 300 C and up to 30 bar pressure
• Offers the option of the use of a fiber optic temperature measurement device for in-situ reaction monitoring



Microwave Sample Prep Product Manufacturers

Anton Paar
SCP Science