Sunday, June 14, 2009

Crowdsourcing solubility requests from bots and people

Now that we have a reasonably routine way of measuring non-aqueous solubility and students trained to do the measurements, we can think about adding some structure to the workflow. By using an open Google Spreadsheet to list the next solute and solvent to measure we can easily crowdsource the requests. This is the dosol sheet and students are instructed to check it before planning their experiments for the day.

Requested experiments come from the following sources:

1) OUTLIER BOT: Andrew Lang has created a neat service that reports measurements exceeding a provided standard deviation to mean ratio (plug into the URL) and a Grubbs outlier threshold. Currently, the "bot" does not automatically write to the dosol sheet but eventually I see that it would make sense to complete that integration. On a daily basis I run it and process the flagged entries in the following ways:
a) If I investigate the corresponding lab notebook pages and find an error in the calculations I simply fix it.
b) If I find that one or more of the measurements are obviously in error I mark the entries as DONOTUSE in the SolSum sheet. This is often a low value that was obtained early on in the project before we appreciated how much mixing is required for some solutes.
c) If I cannot determine why there is a discrepancy I place a request on the dosol sheet. (note: solubilities that are very low (<0.1 M) may have relatively high standard deviation to mean ratios because the techniques we use are not precise at those solubilities and remeasuring won't help)

2) Internal Requests: If someone from within our group is planning a Ugi reaction and there is a missing solubility measurement for one of the reagents or Ugi product, this is a convenient way to request the missing information to make a solvent choice for the reaction.

3) External Requests: When people think about crowdsourcing, usually the first thing that comes to mind is how others can help solve their problem. But in addition to asking what the science world can do for you why not ask what you can do for the science community? We have done so last week and received 3 requests (via a form created by Andy). One for the solubility of iodine in 1,1,2-trichloroethane, one for the solubility of nitric acid in water and another for pyrene in acetonitrile.

For the first request, iodine has no hydrogens so we can't use our standard NMR technique to do it so I set the priority of that request lower. For nitric acid - it is well known that it is miscible in water so we won't be doing that experiment. We also want to focus on non-aqueous solubilities. However the third request was a good fit and Marshall Moritz from our lab processed it right away - he found a value on 0.08M for pyrene in acetonitrile at room temperature (EXP108).

Hadas Joseph from the Agricultural Volcani Center in Israel made the third request. He is a masters student investigating the degradation of pyrene in soil and needs the measurements for extraction experiments. The contacts we make via this route might turn into more involved collaborations or just end up being interesting people to interact with. Either way it benefits science.

4) Implicit requests by keyword searches: We know from our Sitemeter and Google Analytics the keywords that people use to find our site. Most of the time they find the solvent and solute combination that they are looking for but occasionally a combination arises that we have not yet tried. In fact we set up this page with all of the compounds and solvents in my lab to catch new combinations that we could run. This is how the request for phthalic acid in chloroform found its way on the dosol sheet. If someone or something searched for it there is a need for it to exist.

Ultimately, whether entered by human or machine agency, the requests on the dosol list are simply that - requests. It is still left to me to assign the priority in a logical way, allocating resources in proportion to their importance in the portfolio of projects that we are pursuing. One of those projects involves listening to what the global chemistry community is asking for and betting that it will be useful to answer.

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