Pulling It Together
Today is our last day attached to the pier in Punta Arenas before our 0600 departure tomorrow morning. Both the ship's crew and the science teams are working hard to prepare the ship for the cruise. The ship's crew continues to load supplies, store equipment and finish upgrades and repairs. The science teams continue unloading and storing equipment, testing instruments and prepping solutions. Everyone on board is also focused on lashing down anything that can move. The trip to Antarctica requires passage through the infamous Drake Passage. Stories of high winds and treacherous seas are common, therefore, it is important to secure all equipment so that nothing spills, breaks or moves dangerously around the deck.
Bottles, bottles, bottles
Today, I spent time with Travis Mellett (USF) and Sveinn Einarsson (ODU) surrounded by sample bottles in the trace metal clean van. This large container sits on the main deck of the R/V Palmer. The clean lab area (previously wiped down and wrapped in plastic) contains HEPA filters and racks to hold the Nisken or Go-Flo bottles that collect water samples from the ocean. Travis and Sveinn spent the day working in the clean lab to clean, rinse and store smaller sample bottles. The interesting part of this task is that these bottles have already gone through an extensive cleaning process that began approximately six months ago. To understand why these bottles are cleaned so many times, it is important to understand trace metals.
Travis Mellett (USF) and Sveinn Einarsson (ODU) clean bottles inside the trace metal clean lab. The large grey bottles behind Travis and Sveinn are the Nisken bottles that will sample ocean water at various depths.
This is the back of the trace metal clean van. One door will be used to access the inside. Special clothing and attention will be needed once the clean side is entered.
Trace Metals
Trace metals are elements such as iron, copper, zinc, manganese, cadmium, cobalt and nickel that are found in very low levels in the natural environment. When I say low, I mean really low. The trace metals can be detected using special equipment that can measure concentrations at levels of nanomolar (nM or one part in a billion other parts) and picomolar (pM or one part in a thousand billion parts). These small (trace) measurements can be difficult to understand. Think about a trace metal as a single particle of dust. Usually, we only start to see dust when it builds up on a surface. This dust build up is made of numerous individual particles that are extremely tiny. After you wipe away the dust, you have removed the large amount of particles, but there may be one or two individual dust particles on that surface. This would be a trace amount of dust. In the trace metal world, the particles are even smaller than the ones used in the analogy. Due to the extremely small concentrations of these trace metals in the natural environment, contamination by outside sources can lead to changed in the concentrations of natural levels. These changes can lead to inaccurate data and can affect the outcome of the experiments intended for this cruise. So...the question is: How clean is clean?
Clean, clean, clean
In the world of trace metals, trace metal clean (TMC) is a term that is used to describe equipment that was prepared using an extensive process to remove any form of contaminant (organic or inorganic). At the University of South Florida and the Old Dominion University labs, bottle preparation began approximately six months ago. The cleaning process follows a standard protocol and begins with a soap bath for the bottles to remove the organic contaminants.
These sample bottles are washed with Milli-Q and stored in the clean lab for use in incubation experiments onboard the R/V Nathaniel B. Palmer.
The bottles are then treated with a 10% HCl (hydrochloric acid) solution for approximately one month to remove trace metals. The bottles are then heat sealed in plastic, wrapped in another layer of plastic (referred to as the clean layer) and then covered with a final piece of plastic (referred to as the dirty layer).
The crates hold the trace metal clean sample bottles. Inside each bag, six individually heat-sealed sample bottles wait to be cleaned….again.
Upon arrival on the R/V Palmer, the bottles are cleaned again using an ultrapure water known as Milli-Q (trademark name from Millipore Corporation). These bottles are then re-wrapped in a two layers of plastic and stored in the Trace Metal Clean van until use. This extensive cleaning process helps to ensure that the small amounts of trace metals detected in the ocean water are naturally occurring, not due to contamination.
I will admit that I get a little nervous working on projects for trace metal. I am still unsure about what I can touch, whether or not I need to have gloves, what doors can be open and closed, etc. When you understand how important the idea of trace metal clean is to the project, you want to be sure that you are not doing anything to contribute to contamination. Don't worry - if you still aren't sure you understand this whole trace metal world, we will learn about it together over the course of the next few weeks.
Goodbye and Thank You
Cara Pekarcik and Travis Mellett stand on the main deck of the R/V Palmer. Travis will return to USF tomorrow to continue work in the trace metal lab.
I was so happy to be able to work with Travis Mellet today because he will be heading back to Florida tomorrow afternoon. Unfortunately, Travis will not be able to sail on the cruise with the research team, but he has been vital to the success of the preparation. Travis is starting his third year of his PhD program at USF. Travis works in Dr. Kristen Buck's research lab and focuses on organic ligands (more on ligands in the future) and trace metals. It was wonderful to work with this enthusiastic, hard-working, dedicated man. Travis will be missed for his upbeat attitude, knowledge of the trace metal field and diligent work. It was wonderful to meet you Travis - thanks for teaching me so much about trace metal clean!
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