Saturday, March 21, 2009

Flowers in Barrow ... Frost flowers that is ...

It's another weekend here in Barrow, which for us doesn't mean much ... we still work on the weekend like we would any other day. Alexis is busy processing her most recent snow sample. Actually, in this case, the sample isn't snow, but something called frost flowers.

Frost flowers grow on the surface of newly formed sea ice and are very highly saline (i.e. salty). Previous measurements have shown that as these frost flowers form they can scavenge things from the atmosphere, like mercury. So we'd like to know if they can scavenge organic pollutants, like the pesticides and industrial chemicals we are measuring here. If frost flowers are good at scavenging these pollutants we expect to see very high concentrations of the chemicals, compared to other "normal" snow samples we have taken here. So Alexis went out on the sea ice (over the Arctic Ocean) yesterday and sampled four buckets of frost flowers ...

Here is Alexis (blue parka in foreground) getting ready to sample

A closer view of the frost flowers:

An up-close view, showing the structural detail of the crystals:

Today I'm dealing with more mundane tasks, like keeping our GC (gas chromatograph, shown below) happy. I did some routine maintenance today and am re-calibrating the instrument (something I do pretty routinely ... once per week or so). To make sure everything is accurate, this meant remaking the calibration standards, too. Way too tedious for my taste, but something that has to be done ... oh, the life of an analytical chemist.

Since Tuesday I've been monitoring our PCB photochemistry experiment. PCBs are industrial chemicals that are not currently produced in the US (most countries banned production in the 1970s and 1980s), but are found almost everywhere in the environment. They are found in wildlife here in the Arctic, sometimes in very high concentrations, which is a concern. We'd like to understand if there is any chemistry occuring in snow and ice that might affect PCBs and how they cycle around here in the Arctic.

Every day I go out around 1 pm and sample 36 different vials containing different PCB molecules (6 different experiments, 3 "cooked" vials and 3 "dark" vials for each). The "cooked" vials are the ones that have been sitting out on the snow exposed to sunlight and the "dark" vials are control samples that were kept dark, wrapped in foil, in a box buried in the snow. Analyzing these will help us know how much chemistry is caused by sunlight and how much (if any) happens when the sample is not in the sun. Working up 36 samples for GC analysis takes about 2-3 hours ... then another 12-14 hours of analysis time on the instrument. Luckily, our instrument has an autosampler, which means no one has to be around for the 12-14 hours of instrument analysis time ... it does it all by itself! However, once the samples are analyzed, it's another couple hours of work to make sense of the numbers the instrument produces ... (I guess if the instrument did EVERYTHING I'd be out of job, huh?)

Right now, it looks like the two PCB compounds I'm studying are VERY slowly degrading. The degradation is so slow that I've now decided to only go out every OTHER day to sample.

Soon I'll be starting another experiment, with a different compound ... but I'll save the sordid details of that for a later posting ... :)

Oh, and one more thing: Today Villanova's basketball team made it to the Sweet Sixteen. Go NOVA!

1 comment:

Term Papers said...

Frost flowers grow on the surface of newly formed sea ice?I think There had very cold moment.I saw There are many picture interesting and amazing picture's of highly saline.

Term papers