marți, 8 februarie 2011

Probing Green Chemical Analytical Methodologies: A new review of the area

The ACS journal Chemical Reviews appears to be having an edition focusing on Green Chemistry related articles in the near future, by inspecting the ASAP article list for the journal. This is excellent news although it must be emphasised that due to the scope of the subject, it would take an entire journal (of which the RSC has one) and much more coverage dedicated to this multifaceted discipline and its daily development. Assuming the list is comprehensive for the subject as some chemists I've spoken to over the blogosphere seem to feel, would be inaccurate. Green Chemistry is most certainly NOT about just doing reactions in water. It is from mere reflection about looking at the bigger picture, thinking strategically in terms of chemistry/engineering (and understanding and using the associated drivers for industry & within the "real world": economics and sociology).

One article covered by
Chemical Reviews is the following looking more specifically at analytical chemistry in relation to Green Chemistry's agenda (See: "Green Analytical Methodologies" below). Here people can see clean technology development for the laboratory environment which in report form is rather unusual and therefore of interest here. This by definition has implications for other areas within the laboratory setting and converges with other schemes which I shall discuss further below.

The author list for this article includes Dr. Jennifer L. Young whom is Senior Program Manager at the ACS Green Chemistry Institute (USA). She also manages and is a contributing force for the Green Chemistry Resource Exchange itself a potentially amazing tool with ramifications in Knowledge Transfer (KTP), Intellectual Property (IPR) and Informatics, and for education of the public and various industries in general. The goal of the exchange is stated as:
"our mission is to provide the public with a straightforward collection of media dealing with green chemistry and innovative technology as well as the means to share new ideas and research."
A further post will deal with this exchange in due course.

Chem. Rev., DOI: 10.1021/cr068359e
Green Analytical Methodologies
Lawrence H. Keith,* Liz U. Gron, and Jennifer L. Young
Environmental & Chemical Safety Educational Institute, 329 Claiborne Way, Monroe, Georgia 30655, Hendrix College, 1600 Washington Avenue, Conway, Arkansas 72032, and ACS Green Chemistry Institute, 1155 16th Street NW, Washington, DC 20036

1.1. Green Chemistry
1.2. Green Analytical Chemistry
2.Trends in Green Analytical Chemistry
2.1. Greening Pretreatment
2.1.1. Solvent Reduction and Replacement
2.1.2. Solvent Elimination
2.1.3. Derivatization of Molecules and Surfaces
2.2. Greening Signal Acquisition
2.2.1. Spectroscopy
2.2.2. Electrochemistry
2.2.3. Bioanalytical Chemistry
2.3. Greening with Automation and Flow Techniques
2.3.1. Flow Injection Analysis (FIA) and Sequential Flow Injection Analysis (SIA)
2.3.2. Multicommutation
2.4. Green by in-Situ
3.NEMI and Greener Analytical Methods
3.1. Background of NEMI
3.2. Greenness Profiles of Greener Analytical Methods
3.3. Application of Greenness Profiles
3.4. Characteristics of Greener Analytical Methods in NEMI
6.References[Full text in html]
[Full text in pdf]
Copyright © 2007 American Chemical Society

The Introduction:
"For over 10 years, the green chemistry movement has been promoting ways to reduce the risks of chemical use to humans and the environment. An important goal is to develop increasingly environmentally benign chemistries. A relatively underexamined area of green chemistry is analytical chemistry. However, analytical methods are not easily identified as being environmentally benign. Assessment requires careful examination of often complex analytical methodologies within the context of green chemistry. This article attempts to examine qualitatively the scope of green analytical chemistry with a survey of the recent analytical literature to discern common green analytical chemistry themes while creating, and applying, a more quantitative approach to existing environmental methodologies. The authors set forth some basic characteristics, or "acceptance criteria", to which analytical methods should conform in order to be called "green." The application of these criteria, applied to over 800 methods in the National Environmental Methods Index (NEMI), the largest available database of environmental analytical methods, is discussed herein."

I feel this is entirely correct. During the past 8 years I have rarely seen articles within the Green Chemistry arena which have dealt with or suggest mechanisms to link these two areas of chemistry. Although the references list is extensive these merely take snapshot views of particular cases rather than the broader strategic view of the area, it is indeed true the area is relatively unexplored. Moreover for efforts to begin to standardise the greenness of the analysis (as opposed to to the ad-hoc methods currently used) is rarer still. This could be the first such attempt, or estimation of what would be involved, although perhaps the authors of the article Young et al. would be able to provide more information at a later date in subsequent articles?

This is very topical for me at the moment. My recent take up of a role within the biofuels arena, has directly led me to apply analytical chemistry to monitor specifications in the commercial environment (Quality Control/Assurance and process monitoring / process optimisation, this relates to real time monitoring of chemical reaction industrial-processes, and is a fundamental ideal of Green Chemistry). The case is that in the commercial situation these are often the applying of standard-equipment and analytical packages that other organisations generate specifically for that application (example: gas chromatography - Perkin-Elmer or Varian applied to product streams). For example: EN 14214 relating to Biodiesel which I have been working with recently, smaller enterprises don't have the time to generate there own systems until much later after start up and then to put them in place, they are often reliant on the companies providing analytical packages (same examples: Perkin-Elmer or Varian) to provide the environmentally conscious solutions for them and to do so cost effectively. Moreover in the era where energy effectiveness is also critical, such considerations should also include comprehensive energy minimisation as a requirement. It should be noted that this entire Green Analytical Methodologies area also relates closely to the ideals of Good Laboratory Practice (GLP) (*alternative reference*) in my opinion, there is potential that GLP could be one driver for GAM uptake within the laboratory.

This would be via the traditional routes where the European Committee for Standardization (CEN) and American Society for Testing and Materials (ASTM) as well as International standards organisations (such as ISO) could generate the "environmentally conscious" testing regimes where the analytical apparatus providers could then utilise their expertise to rapidly improve the area. There are numerous other layers of organisations that could act here although are not specifically mentioned, such as the US EPA and the European and international equivalents whom also provide vital functions in the area, including establishment of databases for ease of use.

The input of standards here is crucial since the debate is often had particularly with those not familiar with GC is: "what is green?", is it not just another buzz word?
I'm frequently involved in debate going either way as to if a technique or process - IS actually green or not and have to regularly explain how professionals measure if it is or is not.. It's the process of proving the "green" tag and therefore the degree of economic/environmental/social acceptability that many people are not familiar with, or are cynical about. For me adopting a similar approach to that used in intellectual property and "the state of the art" and having improvements over "the art" go far in justifying the tag "green". This is the rule of thumb that should probably be encouraged as it's one the public would most understand, in my personal view.

The "Greenness Profiles of Greener Analytical Methods" section, goes some way to debate and approach quantifiable methods to quantify the issue, in a manner similar to the approaches used in analysis of process chemistry and application (in the most basic sense), the "Green Chemistry Metrics". Further debate and their wider roll out to industry is ongoing.

In summary, this area will continue to grow since this uses the basic principle of establishing of "doing more with less", but doing so such that the materials and apparatus are having the minimal impact in the wider sense. The area is still in its infancy relative to other areas of green chemistry, but will become much more important as methods of monitoring impacts move outward to society at large.

One only has to see the potential for "smart metering" (relating to the "polluter pays principle") to see that such packages could have commercial success, since in order to be green identification of the issues is necessary in the first place, causing industries' and societies greater reliance on advanced analytical chemistry. Green Analytical Methodologies will have significant impacts on their development and will be a further driver towards Green Chemistry and scientific/technological development in general.