Journal of Chromatography A, Volume 1293, 7 June 2013, Pages 36–43
http://dx.doi.org/10.1016/j.chroma.2013.03.040
Million B. Woudneh, M. Coreen Hamilton, Jonathan P. Benskin, Guanghui Wang, Preston McEachern, John R. Cosgrove

• AXYS Analytical Services Ltd., 2045 Mills Road West, Sidney, British Columbia V8L 5X2, Canada
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Entry by Matthew S. MacLennan

There are lots of interesting things about the approach described in this paper. 

Woudneh et al.'s method is mentioned as attempting to quantify NAs based on "equivalents of pyrenebutyric acid (PYB)" (image of PYB below from ChemSpider)
I find the setup here is a bit convoluted, so I will try to clarify it:​

1. Grab sample of OSPW/water filtered, spiked with d19-C10 acid and d31-C16 acid standards, then SPE to isolate NAs. 
d19-C10 acid and d31-C16 acid act as surrogate standards for extraction efficiency.

2. NAs derivatized with EDC become amines, and were then spiked with 13C3-atrazine. 
​3C3-atrazine acts as a recovery standard: monitoring instrument performance and quantifying surrogate recovery values. 

​3. Merichem NAs mixture was used as the quantification standard (calibration curve) for the OSPW samples. Yet, the quantity of the Merichem NAs mixture was translated to units of PYB. It was noted in the paper that the slope of the Merichem NAs calibration curve was 38% of the slope of the PYB curve. PYB was not added to any OSPW samples.

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I feel that the analytical issues involved in quantifying complex unknown mixtures as a bulk material ("total NAs") are important. This study uses a few strategies.

1. Using two surrogate standards for extraction efficiency is a good approach. I feel like they are trying to "bound" the space of SPE binding so that we have a range of recoveries we could reasonably apply to the components of a complex sample.

2. Derivatization using EDC carbodiimide is an important contribution to these types of methods because, in my opinion, it is an attempt to restrict the kinds of fragmentations that could occur in ESI. The assumption is that by doing so, the response factor (ionization efficiency) is almost the same for every type of naphthenic acid species, permitting less error in quantification.

3. The third approach used could be quantifying Merichem NAs in terms of pyrenebutyric acid units. Essentially, the Merichem signal is interpreted on a PYB calibration curve (I hope I have understood this correctly)! Standards are needed, definitely. However, because Merichem NAs calibration curve has a much lower slope (lower ESI-MS sensitivity?) the Merichem NAs concentrations will be squished together on the PYB calibration curve, underestimating the NAs concentrations in solution. Perhaps an improvement would be to interpret toxicity values in terms of units PYB (since toxicity is arguably the most important industrial endpoint) to provide some perspective. 

This paper comes out of the context of the quantification of total naphthenic acids. The approach outlined here is fantastic but not without its limits. Are the limits enough to discredit the method? I don't think so. That's why I chose it for the journal club's first paper!

Journal of Great Lakes Research, Volume 40, Issue 2, June 2014, Pages 226–246
http://dx.doi.org/10.1016/j.jglr.2014.02.004
​
Posted by Chris Mallon,

​Of all the Laurentian Great Lakes, Lake Erie is the most sensitive to eutrophication. Its sensitivity arises from its shallow depth, making the water warmer and more amenable to algae growth. Lake Erie also receives direct runoff from major cities and intensely-managed agricultural landscapes in Canada and the United States. Lake Erie has therefore been one focal point for the study of eutrophication in freshwater ecosystems.

This article focuses on phosphorus as the main causal factor of eutrophication in Lake Erie. The article covers the history of phosphorus loading, explains the difference between total phosphorus (TP) and dissolved reactive phosphorus (DRP), and explains the impacts these nutrients have on algal growth, dissolved oxygen, and ecosystem health. It also provides a summary of agricultural best management practices (BMPs) that influence the release of TP and DRP into the Lake Erie ecosystem. A summary of the implications of climate change is provided, explaining the impact of more extreme weather events on the phosphorus loading trends already noted. The article concludes with a section describing policy and management implications.

This article offers value in several ways. Firstly, it provides an effective summary from many different disciplines to explain the overall impacts that phosphorus loading is having on the Lake Erie basin. In doing so, it also functions as an annotated bibliography for anyone interested in discussing or learning about the impacts of phosphorus on freshwater ecosystems. Secondly, it provides rare clarity on the historical progression of phosphorus contributions to the Lake Erie ecosystem, synthesizing many different datasets. The context and difference between point source and non-point source pollution is explained, with the overall message being that eutrophication is recurring now because of an increase in non-point source pollution. Thirdly, it very clearly outlines the different sources, both spatially and by industry, of the P loading. This enables one to get a sense of both the volume and nature of the phosphorus entering Lake Erie. Finally, it explains the basic difference between DRP and other types of P in light of the management challenges. The reader can gain a clear understanding that the re-eutrophication of Lake Erie is occurring largely due to the increase in dissolved reactive phosphorus.

​In summary, this is a multi-disciplinary introduction to freshwater eutrophication in the Great Lakes as a result of phosphorus loading.

Let's get the ball rolling!
We are expecting this online journal club to provide the following:

1. Participation at your own pace on the topics you love.
2. Ability to innovate and cross-pollinate within the journal clubs.
3. A place for useful resources for your colleagues and the public with regards to the environment and its chemistry.
4. Clear language characterizations of the challenging environmental problems that society and scientists face and the questions research is attempting to address.
5. Mapping out the environmental research ecosystem and other associated networks (funding, industry, organizations, etc...)
6. Topics of interest that need urgent study.

useful, professional, innovative!

Please stay tuned for great articles and commentary in the near future!

​If you are interested in contributing, contact the editor

Welcome to the home of the Canadian Institute of Chemistry Environmental Division Journal Club(s)! 


Essentially:

This blog-style repository of online journal clubs is a place to exchange learning, research and resources in a professional and pragmatic way, and to foster connections between researchers, educators and the public. We are looking for excellent quality reviews and discussions regarding cutting-edge research in environmental science and chemistry. Research is progressing at an exponential rate and the complexity of problems is staggering. The journal club is here to help!

The content is open access. Please contribute! 

If you want to contribute to a topical journal club with an article or make a new journal club keep reading below!


How do I get started with a journal club?

1. To begin your own journal club here, all you need to do is post an article with a hashtag (or set of tags) that is unique to your topic of interest.
2. Find a major topic to start. "Oil Sands Process Affected Waters" is an example of a current substance of environmental concern that generates a lot of discussion. "Toxicity" is also a great topic. I could tag my article with Oil Sands Process Affected Waters or a suitable acronym.
3. Choose a research article that is important to begin discussion on your topic. Write your summary of the article, thoughts, questions and whatever else. 
4. Email cicenvjc@gmail.com (a CIC Environmental Division Member) with the attached post and tags. 
5. The editor will quickly review your work and post your journal club article (barring any obvious red flags).
6. Wait for your colleagues to carry on the discussion!

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How do I post an article in an ongoing journal club?

Easy! 

1. It is the same as in How do I get started with my own journal club? above, EXCEPT you should know the hashtag(s) that represent the journal club of interest. You need to use those hashtags.
2. Email the editor (CIC Environmental Division Member) your post and tags and based on the traffic he will post it on this blog as soon as possible.

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How do I respond to a posted article?

Anyone can leave their own remarks below the journal club post as a comment.

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How do I find a journal club?

The journal clubs will be found based on the hashtags that describe the topic. Click hashtags to find topics or search a topic and find associated hashtags to the right of the entry.

As a side note: It is important for us to get to know you! If you cannot find your topic of interest or don't know, email us, introduce yourself and we will get you connected!