Helen K White Lab

One of the trickiest parts of organic geochemistry is liquid-liquid extraction (or as I have rechristened it, “lick-lick-ex”).  The purpose of this procedure is to move gunky organic matter in and out of different solvents depending on whether we want to transport, measure, or react our material. It is finicky, crazy-making work as well as a formidable obstacle in my research. The following comic illustrates my daily struggles:

I. Cloudy solution after RuO4 oxidation, part DCM and part water

II. Adding a few drops of DCM helps separate the mixture into two layers

III. Adding a drop more of DCM warps gravity inside the separatory funnel

IV. Contents of funnel suddenly celebrates marriage laws in the state of New York

V. Extraction goes awry when the sep. funnel bursts into boiling flames of acid

VI. Suddenly the encouraging face of Jesus appears in the depths of the funnel

VII. Finally a drop of water separates the aqueous and organic layers

VIII. Until the funnel shatters when Katie tickles Zach while he holds delicate glassware

I forgot to mention, on the way home from group meeting at Peace a Pizza we picked up some crayons so that we could decorate the lab with beautiful illustrations of our work:

As a preface to the following post, I did do a lot of work this week. I desulfurized my saponified residues of total lipid extraction as well as my extracts of my saponified residues of total lipid extraction AS WELL AS my saponified total lipid extraction (for those of you who think this lab is all fun and games).

Helen was attending a conference in Vermont for a few days so naturally we did double the usual amount of work without her distracting presence. These pictures explain this week pretty well :

Hello everybody,

My name is Martin and I’m a sophomore from Belmont, MA. While the lab seems to be invaded by a variety of creatures this summer, I had the foresight to decide to intern at a lab off campus. Thanks to a KINSC Summer Stipend, I am spending my summer in David Johnston’s lab at Harvard University in Cambridge, MA doing some biogeochemsitry. Avid followers of the blog will notice that Emily worked in the same lab last summer with her aptly named post Summer Rocks. For a few more facts about me and Haverford: I play Ultimate Frisbee for Big Donkey Ultimate, and play upright bass in various ensembles on campus.

In my work this summer, we are analyzing shale rocks from a few sites in Utah to determine the sulfur, iron and carbon compositions of the rocks. The work is supervised by Ben Gill, a post-doc in the lab. Our goal is to determine the environment of the ocean at the time the rocks came from and figure out why it was that way. These rocks are from the early Cambrian era (about 500 million years ago). After spending the first few days becoming friends with the shatterbox, the first methods I used to analyze the samples was CRS, which extracts Chromium Reducible Sulfur. This method is a great example of Redox chemistry at work. After adding HCl to the sample to release the carbonate, a solution of CrCl2 (blue) is added and nitrogen gas is bubbled through. Over the course of two hours, the chromium is oxidized, turning green, and the sulfur in the rocks is reduced and is liberated as H2S which is then captured in a zinc acetate solution as ZnS. Then by adding Silver Nitrate, we have a precipitate that can be filtered out and analyzed in the mass spec to determine which sulfur isotopes are present.

The most popular man on campus, John Harvard, makes hundreds of new friends daily. And look at those shiny shoes!

The Chromium chloride starts out as a blue solution...

Adding Chromium Chloride

Aloha Civilians,

I apologize for the recent hiatus in blog posts, we have been busy dealing with a multitude of problems in lab this past week:

1. A recent badger infestation required an evacuation of the lab until Katie could brew all of the badgers into sweet badger tea. The lab enjoyed this beverage together during group meeting.

Badger blood is a delicacy in Katie's home state of Georgia

2. Our lab is in the midst of another infestation: C16 and C18 fatty acids. These little buggers come from your cell membranes and will contaminate your samples, even with the most diligent glove-wearing and triple rinsing with our delicious flavors of solvent: MeOH, DCM, and hexane. On Friday we came to the unsettling conclusion that if you breathe next to a clean GC vial, derivitize that seemingly empty vial, and run it thru our GCMS,  peaks for C16 and C18 fatty acids will dominate your spectrum! While I am pleased that I can now tell the world that I breathe acid, this contamination is not so helpful for chemistry. To curb the spread of these demons, the following protocol will be observed:

- Breathing is now prohibited in lab, all researchers must breathe thru Teflon coated Scuba gear when walking around lab

Sarah's roommate modeling our new outfit

- No exposed skin in lab

This baby is well prepared for environmental chemistry

3. Raney Nickel, my prized catalyst, is a dangerous compound known to explode in flames when exposed to air. I was disappointed nervous when my own Nickel was not that dramatic, so last week I ran a quick test to see if the catalyst was indeed functional. To my relief, I successfully desulfurized 2-mercaptoethanol and confirmed the efficacy of the catalyst. The downside was that I smelled like 2-mercaptoethanol for the rest of the day (for those of you who don’t know, this compound smells like the farts of a horse that eats rotting eggs). Our lab neighbor, Karin Akerfeldt, fondly informed me that I should take a bath in bleach to get rid of the smell.

In other news, our lab enjoyed a lunch expedition to Suburban Square last week. This brief vacation included visits to Sweet Green, the candy store, the Apple store, and possibly a parking ticket. Look how spoiled we are:

(L-R) Helen, Sarah, and Ingrid enjoy their candy

Until next time, ponder this question: are you a mongoose or a penguin?

Hello! My name is Ingrid and I am a rising senior working this summer to plan new labs for Helen’s “Introduction to Molecular Thermodynamics” course. While the rest of the White lab crew is saving humanity from extinction one heroic discovery at a time and still finding time to fight dinosaurs and attend funerals, I am bumming around the science building reading magazines, getting gas and drawing pictures.

Well, kind of. The first week I dove into a crash course on pedagogical approaches to teaching science in the laboratory. Like a shiny penny at the bottom of the pool, I got my hands on a PRINT VERSION of the ACS Journal of Chemical Education. While online publications are convenient to access from my dorm room at 1:30 am on the morning of a deadline, nothing replaces the satisfaction of leafing through pages of print journals. A quick dip in pedagogical theory armed me with the vocabulary to participate in the current discourse as we apply it to the lab component of Helen’s course. The lab is centered around two project-based learning goals: synthesizing biodiesel and working with fuel-cells. Each laboratory period will incorporate guided-inquiry techniques. For example, the teaching assistants will be armed with leading questions to pose to students while they work.  It has been interesting to note that seriously thinking about laboratory learning is nourishing my blossoming appreciation for Superlab, the Haverford Junior mandatory laboratory course ….now that it’s over.

During week two, I skipped the gas pump and produced biodiesel myself. By the end of the week I felt like I’d been swimming in biodiesel. But only figuratively, because the 50 mL I synthesized in lab wasn’t enough to dip my toes in.  Also, who wants sock fuzz in something that powers a diesel engine, back-up generator, and camping lantern? This summer, the oily nature of my work and the limited surface space in Helen’s lab has prompted me to mostly set up shop in Superlab and the chemistry lounge. While I miss the daily lab banter, I enjoy hearing reports over lunch, during lab meeting and through the blog.

With a biodiesel procedure in hand, last week I compiled the laboratory manual! I’m excited to incorporate cartoon illustrations that demonstrate techniques next to the procedures. I’ve only just started sketching, but hopefully we can find a classy place for them. The first test run of the lab manual is this week, so cross your fingers! It still needs edits, so I’m off!

This week’s forays into the wonderful world of Raney Nickel catalyst have filled my bench with some beautiful green nickelous solutions (not to be confused with this guy.)

After struggling to describe the exact shade of green in my pear-shaped flasks (radioactive vomit green? tree frog liver green? Rachel Green?), I decided to collect all of the green objects in the lab for comparison.

A collection of green things artistically arranged by Sir Zach Rosenthal (not shown: a green hippopotamus named Gerald that wandered into lab last night)

Katie was disappointed that I had not plucked out one of my seductively green eyes for this viridescent smorgasbord, but alas Sarah was using all of the forceps for stuffing columns. Incidentally, green eyes are one of the many traits I share with the greatest man who ever lived, Harry James Potter. I am looking forward to seeing his biopic on July 15th, and you should too.

Today we mourn the loss of Raul, one of our beloved separatory funnels.

Raul leaves behind his wife and three 25 mL beaker children.

Raul's wife weeps over his decapitated corpse

We as members of Helen White’s lab gather to eulogize Raul and share our memories of him:

Sarah: Raul was like family to me. No seriously, he was my cousin.

Danny: I can’t pretend to be upset, I’m totally going to go for that wife of his now.

Liz: Sorry — I’m a bio major — what is a separatory funnel?

Katie: Raul? I sneezed all over him this morning when I took him out of the combustion oven. Don’t tell Zach.

Helen: There goes $70.

Greetings Muggles,

My name is Zach, I’m a sophomore from New Jersey and am delighted to be doing research in the chemistry lab supervised by Professor Helen White at Haverford College. Important facts about me: I like popsicles, watching YouTube videos about baby sloths, and doing crossword puzzles. Chemistry is pretty cool too.

The past two weeks have been a whirlwind of passionate pipetting, manic solvent rinsing, and (as the title of this post suggests) a fantastic 90′s pop music Pandora station. I am astounded by the amount of information I have digested in such a short period of time. My research this summer (graciously funded by some dead guy) investigates why we release elemental sulfur upon sequentially degrading atmospheric organic matter. Is the sulfur chemically bound to organic particulate in the air? Is elemental sulfur entrapped in some sort of macromolecular matrix (so many m’s!) which we then crack open chemically? Are we the ones creating the elemental sulfur with our sequential degradation reactions? Upon seeing its friends, does sulfur opt to sit in the front seat or kick it in the back seat?

The answers to these questions still elude us, but we will make headway tomorrow when we subject our aerosol residues to Raney Nickel catalyst, which we hope will be an effective desulfurizing agent to test if the elemental sulfur released by sequential degradation was originally chemically bound. In the mean time, enjoy these pictures of some charming creatures I encountered in the lab: