The choice of reagents is critical for improving the sustainability of sample preparation and directly impacts the reagent consumption and the waste generation.
Evaluating the method from a chemical standpoint involves several factors:
Evaluating the method from a chemical standpoint involves several factors:
Moving toward greener procedures requires a thorough evaluation of these parameters while ensuring successful digestion to maintain analysis quality.
Microwave digestion provides highest performance and excellent chemical compatibility, enabling the evaluation of greener chemistry and reduce volume of reagents. Studies have demonstrated that using tougher digestion conditions beyond the capabilities of traditional systems can reduce the overall volume of acids, limit the use of harsh chemicals, and enable the use of diluted acids, all of which led to lower waste volumes too. While these improvements may not always apply to all matrices, chemists must consider these parameters to develop greener protocols.
GreenPrep MW Score
By evaluating your laboratory procedures, Green Prep MW Score provides actionable insights to reduce environmental impact while optimizing efficiency.
Green metric for microwave-assisted sample preparation for elemental analysis: GreenPrep MW Score
Advances in Sample Preparation
Volume 16, October 2025, 100216
The technological design of the digestion systems significantly impacts sustainability through recyclability, energy consumption, and gas waste generation.
The design of the digestion systems involves evaluating these factors to enhance sustainability. Taught matrices often require HF, necessitating the use of PTFE-TFM vials, which are not highly recyclable. However, reducing consumption by minimizing vessel dimensions and enhancing their durability can mitigate this issue. Microwave technology optimizes these parameters. Additionally, their extended lifetime compared to other vessels ensures consistent pressure inside and outside the vials.
Considering the green aspects of the sample-to-analysis journey, several actions can be taken to optimize them.
While digestion plays a central role in sample preparation for elemental analysis, several other key steps can be optimized to make the entire process more sustainable and safer for the operator.
These decades of experience have led Milestone to the development of several tools to address most routine tasks to make the sample preparation process more sustainable. Reagents handling, cleaning approach, supply of ultrapure acids and the handling of digestion vessels are all parameters to consider. In fact, all of them have an impact on sustainability.
These decades of experience have led Milestone to the development of several tools to address most routine tasks to make the sample preparation process more sustainable. Reagents handling, cleaning approach, supply of ultrapure acids and the handling of digestion vessels are all parameters to consider. In fact, all of them have an impact on sustainability.
Ultra-pure Acid Supply
High-purity reagents are a vital component of sample preparation because they directly affect the blank value. The use of purified acids is a common practice in all laboratories. However, it is well demonstrated that the daily routine can significantly contaminate the acid. When the acid bottle is opened, it is exposed to contamination either from potential procedural errors by the chemists or simply from being stored for an extended period.
Sub-boiling acid purification with quartz or PTFE boilers offers a way to produce ultra-pure acid on demand from technical-grade acid. These systems effectively distill the acid into a fresh and purified reagent, minimising waste generation.
Reagent handling
Reagent addition is typically performed manually and poses risks of exposure to acid vapors the operator and to potential contamination the sample. Adopting an automated dosing station reduces operator exposure to concentrated acids, including HF, and minimizes the risk of contamination and human errors, which avoid useless waste of acid and sample reprocessing. This station facilitates the addition of reagents directly into digestion vessels or vials without human intervention.
Steam Vessel Cleaning
Most laboratories clean in large containers with several liters of acid for hours, often repeating this step up to four times. This approach raises significant concerns regarding safety, reagent consumption, waste and energy consumption, as the process is done under vigorous boiling. Using a microwave system to perform cleaning cycles offers a more efficient, safer, and greener approach to handle this task. However, acid steam cleaning presents an even more sustainable method. This system enables efficient cleaning of digestion vessels, vials, and other labware used in elemental analysis, using only a fraction of the acid typically required either with traditional approach.
All the parameters and considerations discussed are crucial to optimize the sustainability of the entire sample preparation workflow.
This holistic approach ensures that each aspect of the process adheres to sustainability principles, enhances efficiency and safety, and benefits both the laboratory and the environment.
This holistic approach ensures that each aspect of the process adheres to sustainability principles, enhances efficiency and safety, and benefits both the laboratory and the environment.
Milestone™ SpA
Via Fatebenefratelli 1/5 - 24010 Sorisole (BG) - Italy
Phone: +39 035.573857 | Fax: +39 035.575498
Via Fatebenefratelli 1/5 - 24010 Sorisole (BG) - Italy
Phone: +39 035.573857 | Fax: +39 035.575498
Milestone™ SpA
Via Fatebenefratelli 1/5 - 24010 Sorisole (BG) - Italy
Phone: +39 035.573857 | Fax: +39 035.575498
Via Fatebenefratelli 1/5 - 24010 Sorisole (BG) - Italy
Phone: +39 035.573857 | Fax: +39 035.575498