follow url MICROWAVE MODULAR ROTOR MMR-15: microwave modular rotor

go here The newly designed ETHOS UP and ETHOS EASY fully embody Milestone’s philosophy in microwave sample preparation. They encopasses Milestone’s visionary concept of “Total Microwave Sample Preparation” and, with a comprehensive choice of accessories, they offer a complete first-class solution also for sample drying, vacuum evaporation, solvent extraction, protein hydrolisis, and alkaline fusion. “The removal or reduction of the quantity of the hydrochloric and hydrofluoric acids prior to analysis may be desirable. Evaporation to near drynaess in a controlled environment with controlled pure gas and neutralizing and collection of exhaust interactions is an alternative where appropriate. This manipulation may be performed in the microwave system, if the system is capable of this function…” US EPA method 3052 The US patent 5,447,077 attested the pioneer work of Milestone in the investigation of the unique heating mechanism of microwave-assisted evaporation process. The new MMR-15 rotor takes advantage of this technology and it is now available to chemists to improve the quality of the analytical results and to reduce the overall sample preparation time.

click Extract from US patent 5,447,077
Extract from US patent 5,447,077

MMR Technology

source url Most US EPA microwave acid digestion methods (3015, 3051 and 3052) prescribe the use of combinations of HNO3, HF and HCl. HNO3 is typically required as oxidizing acid, HF is used for silicates and HCl is recommended for soils and sediments. Solutions obtained by closed vessel digestion must often be evaporated prior analysis either to concentrate the elements of interest or to eliminate compounds which may interfere with the analytical technique being used.
A typical setup for microwave-assisted evaporation consists of the ETHOS UP or ETHOS EASY equipped with the VAC-1000 vacuum scrubber and the MMR-15 rotor.
The MMR-15 can be used for vacuumassisted sample drying prior digestion, and solution concentration at the end of the decomposition process. The MMR-15 accommodates up to 15 TFM vessels of 100 mL. They are the same vessels used in the SK-15 digestion rotor, so no transfer of the solution is required when performing drying and concentration. This minimizes the risk of contamination or loss of the analytes of interest. Each vessel fits snugly into an adapter which perfectly seals the system. An adjustable valve with in-line filter regulates vacuum and air flow. All surfaces in contact with the solution are made of high-purity TFM. Sample are therefore processed in a clean, inert environment.
The VAC-1000 integrates a vacuum pump, a water cooled condenser and a neutralizing module to properly and safely handling acid vapors; it is the perfect complement to the MMR-15 rotor.

traduire agence de rencontre en anglais Evaporation time for HCl, HNO3 and HF

site de rencontre pieds Evaporation time for HCl, HNO3 and HF

MMR Chemistry

rencontre loto foot The paper “Use of Microwave-Assisted Evaporation for the Complete Recovery of Volatile Species of Inorganic Trace Analysis”, written by Skip Kingston and Dirk Link, and published in Analytical Chemistry some years ago, did compare the heating mechanism of hot plate and microwave assisted evaporation. It was demonstrated that -when using microwave, elements loss by volatilization is minimized, because the temperature of the solution decreases as volume decreases during the evaporation process. Subsequent re-dissolution and analysis of the residue by ICP-MS showed that a complete recovery was achieved when using microwave-assisted evaporation.

go MMR Chemistry

Temperature of solution as volume decreased during microwave-assisted and hot plate evaporation. The final point in the hot plate temperature profile is that of the beaker bottom at dryness.

Element Microwave evaporation Certified value
Ag 1.53 ± 0.04 1.68 ± 0.15
As 13.8 ± 2.2 14.0 ± 1.2
Cd 4.13 ± 0.24 4.15 ± 0.38
Co 0.49 ± 0.02 0.57 ± 0.11
Cr 1.76 ± 0.03 1.43 ± 0.46
Hg 0.063 ± 0.033 0.0642 ± 0.0067
Mn 11.5 ± 0.5 12.3 ± 1.5
Ni 2.29 ± 1.02 2.25 ± 0.44
Pb 0.38 ± 0.07 0.371 ± 0.014
V 4.59 ± 0.27 4.68 ± 0.15

Concentration of analytes (μg/g) in SRM 1566A (Oyster Tissue) following the microwave-assisted evaporation of the digestate compared with the certified total concentrations (uncertainties are expressed as 95% confidence intervals, with n ≥ 3)

Ultratrace Inserts


Ultratrace Inserts

To keep blank levels as low as possible the analyst must exercise care in keeping the volume of reagents to a minimum
T. Murphy, The role of analytical blank in accurate trace analysis.

Vessel-inside-vessel schematics

Vessel-inside-vessel technology was developed by Milestone in the late 90s. Vessel-inside-vessel technology uses a smaller secondary vessel inside the primary microwave vessel.
The secondary vessel contains the sample and digestion reagents, and the primary vessel contains the solution required to achieve accurate temperature monitoring. This configuration reduces the amount of acid required for digestion to near stoichiometric quantities, which reduces the dilution factor and increases the detection limit.

The use of vessel-inside-vessel technology is also used for the processing of larger organic sample sizes.
This is accomplished by controlling the reaction kinetics and lowering the pressure inside the microwave vessel. Controlling reaction kinetics is especially important when trying to digest large quantities of organic material. The use of vessel-inside-vessel technology helps to control these exothermal reactions by providing a heat sink for the energy liberated during oxidization.

This is accomplished by placing water in the outer microwave vessel. The water draws the heat away from the reaction mixture, slowing down the reaction kinetics and preventing a runaway reaction.
A variety of inserts are available from Milestone, in different materials (Quartz or TFM) and with different sizes and shapes, to accomplish all application requirements.


  • Less acid volume
  • Higher sample amount
  • Lower dilution factor
  • Increased method detection limit
  • Less surface contamination
  • Lower analytical blank

No cross contamination

Three blanks were analyzed in run #1. The same blank was prepared along with two Animal Tissue samples, showing no cross contamination.


Run #1
Vial Cr (ug/L) Cu (ug/L) Mn (ug/L) Ni (ug/L) Pb (ug/L) Zn (ug/L)
Blank 1 <2 <2 <2 <2 <2 <10
Blank 2 <2 <2 <2 <2 <2 <10
Blank 3 <2 <2 <2 <2 <2 <10

Blank 2 mL HNO3. Analysis by ICP-AES


Run #2
Vial Cr (ug/L) Cu (ug/L) Mn (ug/L) Ni (ug/L) Pb (ug/L) Zn (ug/L)
Sample 1 54,8 40,0 14,4 31,6 11,0 148,5
Sample 2 56,1 40,0 14,3 32,6 10,8 148,2
Blank 3 <2 <2 <2 <2 <2 <10

Sample weight 100 mg. Blank 2 mL HNO3. Analysis by ICP-AES

Complete recovery

Element Ultratrace Inserts
(mg/kg) (n=3)
Certified (mg/kg)
As 3,9 4,1 ± 0,5
Cd 19,5 19,6 ± 1,4
Pb 13,4 13,6 ± 0,5
Sb 9,6 10,1 ± 1,6
Zn 135 137 ± 20

Polyethylene EC680K
Sample weight 200 mg. Blank 2 mL HNO3. Analysis by ICP-AES
Element Ultratrace Inserts
(mg/kg) (n=3)
Certified (mg/kg)
Cu 14,8 16,8 ± 1,0
Fe 70,0 79,3 ± 8,3
Mn 8,3 8,8 ± 0,4
Zn 156 163 ± 7

Human Hair IAEA 085
Sample weight 100 mg. Blank 2 mL HNO3. Analysis by ICP-AES

Connect With Us

We're social people, so get in touch. Follow us and be the first to hear news,
get updates and new releases.

Milestone Srl - Via Fatebenefratelli 1/5, 24010 Sorisole (BG), Italy | Copyright © 2013 | Cookie Information | Login