Things Are Not What They Appear

So I finally received my Arsenic in the mail the other day. Actually, it's not Arsenic, per se, but a salt compound called sodium arsenate. When the salt is dissolved in water, you then have a mixture containing sodium ions and arsenate ions. Arsenate, commonly referred to as As[V] due to its pentavalent electron structure, is often encountered in nature. And detection and monitoring of arsenate is a research effort of notable interest due to its high toxicity - it is Arsenic after all.

We've set about developing a detection method for arsenate, which is based on one overarching principle of the substance: As[V] quenches fluorescence. This is theoretically true, as the arsenate ion should act as a potent electron acceptor. There are several research groups using fluorescent silole compounds to detect the presence of As[V] via electron quenching in such a manner. See here (subscription required) and here.

But there's a problem with all this. I tried to replicate Stern-Volmer quenching plots for As[V] last week and...well...let's just say I didn't get the same results. My results were not necessarily bad; just unexpected. I'm sure that the data will end up in a manuscript shortly. And once the paper is published - which will be in, like, two years - I'll post a link to it on this blog. Until then, you'll just have to imagine what the data looked like...