Microwave Extraction System for GC and HPLC Analysis

Samples submitted for GC and HPLC analysis require pre-treatment. The fundamental step in sample pretreatment is compound extraction from the sample matrix. This is the least evolved -many people still use the Soxhlet extraction method invented in 1879-, most error-prone step in the overall analytical procedure.



Microwave extraction is completed in just few minutes. The Milestone ETHOS X can simultaneously process multiple samples in a matter of minutes. Microwave assisted extraction uses closed vessels to heat the extraction solvent above its atmospheric boiling point. The elevated temperature increases the solubility of the analytes of interest and lowers the viscosity of the solvent, allowing it to better penetrate the matrix. This reduced extraction times.


An important feature of the ETHOS X system is that it easily adapts to existing extraction chemistry. This is accomplished through the use of a unique, patented material, called Weflon. Without Weflon, extractions could only be performed with polar solvents (Acetone, Methanol, etc.) or mixtures of polar and non-polar solvents, because non-polar solvents are not heated by microwaves. Weflon eliminates this problem by acting as a coupling agent. Weflon stir bars are heated by microwaves and they subsequently transfer this heat to the non-polar solvent.


Microwave extraction produces equal or higher analyte recoveries than older methods. Thanks to a combination of higher extraction temperatures, closed vessels, magnetic stirring, and precisely controllable temperature conditions, users of microwave extraction can expect a better quality of the results. The homogeneity of the microwave field and the precision of the temperature control are key elements in microwave extraction.


Lower solvent usage reduces the costs of solvent purchase and disposal. Microwave extractions are carried out in closed, sealed vessels. The matrix is constantly bathed with hot solvent in a self-promoting reflux action with no loss of volatile analytes or solvent. The use of closed vessels, with the speed and efficiency of microwave heating, allows extractions to be performed with significantly less solvent, without sacrificing accuracy or precision. The simplicity of the microwave technique reduces the attended labor time and increases overall productivity.

Higher microwave power for faster vessel heating

Pressure-responsive door schematics.
Direct and contact-less temperature control in all vessels.

largest microwave cavity

The ETHOS X microwave cavity has a volume in excess of 70 liters, by far the largest currently available. Why is this important? Firstly, extraction rotors with more sample positions can be accommodated, improving productivity. Secondly, the microwave unit is inherently much safer, because a larger cavity better contains gases escaping from vessels, should there be a sudden over pressurization.

Highest Microwave Power

Equipped with two 950 Watt magnetrons for a total of 1900 Watt, ETHOS X is the most powerful microwave extraction system available in the market today. The system additionally employs a rotating diffuser that evenly distributes the microwaves throughout the cavity. High power coupled with the diffuser enables very fast heating of high throughput rotors.

Pressure-Responsive Door

The ETHOS X’s stainless steel door features an innovative opening and self-resealing mechanism. In case of a sudden over-pressurization of the cavity, the door slightly opens for rapid pressure release and the microwave power is instantaneously cut off. Immediately afterward, the door is pulled back, resealing the cavity. An automatic door locking system does not allow the user to open the ETHOS X door during the run.

Temperature and Pressure Sensors

The most advanced yet easy to use reaction sensors are installed for complete quality control of the extraction conditions. Direct temperature and pressure control are used in a single reference vessel. In all vessels, contact-less temperature is used combined with a contact-less pressure sensor that monitors and controls all vessels simultaneously, preventing any leakage or venting.


Operating Software
The ETHOS X is controlled via a compact terminal with an easy-to-read, bright, full-color, touchscreen display. The terminal is provided with multiple USB and Ethernet ports for interfacing the instrument to external devices and to the local laboratory network. The terminal runs a completely new user-friendly, icondriven, multi-language software to provide easy control of the microwave run. Simply recall a previously stored method or create a new one, press ‘START’ and the system will automatically follow the user defined temperature utilising a sophisticated PID algorithm. Several applications, including all US EPA and ASTM methods available, are preloaded in the ETHOS X terminal. There is no need to input the number of samples or weights being extracted, as the software will automatically regulate the microwave power accordingly. This assures a consistent quality of extraction and simplifies the use of the instrument.