ACS GCI Pharmaceutical Roundtable

About the AMGS Calculator

AMGS Calculator

This tool is intended as general metric guideline to compare methods during development. It is not meant as an absolute measure of method greenness or as a means to reject a given method based on the finite score. The lower the AMGS, the greener the method.

The AMGS metric factors solvent health, safety, environmental impact and cumulative energy demand, instrument energy usage and method solvent waste to benchmark and compare one method to another. The team feels that having this metric available will provide an environmental impact awareness and encourage analysts to develop greener methods.

The color coding is meant as a guideline that indicates if a specific energy score (of the three noted categories), tips the balance of the AMGS total % beyond a ~1/3 contribution. These colors are meant as an indicator highlighting the highest contribution to the AMGS value. Yellow and red colors were used to highlight areas where the method could be improved; for example, in the table above, the instrument energy could be reduced by shortening the method run time.

The system suitability test (SST) is typically 0.05% (v/v) relative to the API reference standard. If this solution is prepared through serial dilution, please provide the total volume of dilutions used to make the final solution.

Where both a resolution and a sensitivity solution are used, the total volume should be included for both solutions in the sensitivity solution entry.

This calculator is for determining liquid chromatography and SFC greenness scores only. It is not currently designed for gas chromatographic methods, although the team welcomes specific suggestions for future versions.

Send Us Feedback

Please e-mail for specific details on how to improve the AMGS, so we can address your comments in future iterations of the tool.


This calculator was developed from a Microsoft Excel-based program first developed by Laurent Lehman at Bristol-Myers Squibb, New Brunswick and further improved through development by members of the American Chemical Society (ACS) Green Chemistry Institute (GCI) Pharmaceutical Roundtable’s Analytical Chemistry team.

The members that contributed to the development and launch of the calculator are: Michael Hicks (Merck, Rahway, NJ), Bill Farrell and Christine Aurigemma (Pfizer, San Diego, CA), Paul Ferguson (AstraZeneca, Macclesfield, UK), and Dave Constable, Isamir Martinez and Christiana Briddell (ACS GCI, Washington, DC).

Others that tested the calculator with HPLC, UPLC, SFC or Preparative HPLC- or Preparative SFC- methods are listed as co-authors in the following Green Chemistry publication:

Use the following web link to read this paper.


The American Chemical Society Green Chemistry Institute’s Pharmaceutical Roundtable (“the Roundtable”) has created this AMGS calculator to inform and guide users towards greener methods. The Roundtable has used reasonable efforts in collecting, preparing and providing quality information and material, but does not warrant or guarantee the accuracy, completeness, adequacy or currency of the information contained in the AMGS calculator. By downloading, viewing and utilizing information from the AMGS calculator, visitors assume full responsibility for their own actions and any damages or liabilities that may result from the utilization of information obtained from the AMGS calculator.

Should you have any questions or comments about the AMGS calculator or this disclaimer, please send an e-mail to

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