Monday, August 5, 2019

Setting up an isotope lab

John Hayes, Marilyn, Tom Hoering, Geophysical Lab, 1983
Marilyn and son Evan Swarth new IRMS 1999
It was in the mid-1980s, 1985 I think, when the Geophysical Lab purchased a large format, orange-colored 251 IRMS to measure SF6 for all four stable sulfur isotopes. Back in those days, Finnigan made custom instruments for its users, similar to the now defunct Nuclide Corporation (State College, PA). Our other IRMS systems at that time were Nuclides and a home-made IRMS with a Nier-wound magnet. The 251 came with a first version of Isodat, which was run on one of those little Apple computers that many have kept in their basements as antiques. The valves were operated by rectangular, green-lighted push buttons. The dual inlet system and vacuum system were controlled, then, not by software, but with these buttons.
         The instrument had been installed by German and American engineers in Tom Hoering’s old Geophysical Lab laboratory. In those days the acceptance of a new instrument brought in Finnigan “brass”—vice presidents, Chuck Douthitt’s bosses—essentially men in suits who stood at attention when the instrument was being demonstrated.
         Staff scientist Tom Hoering, a modest man, was the anointed person to handle the analysis of the first sample. Doug Rumble and I, mere children in those days, stood at attention behind Tom, looking on as required by strict German protocol. It didn’t take but a few minutes for Tom to push the wrong button and vent the IRMS. Imagine the slowing whine of the turbo pumps and the disappointed looks on the Finnigan faces. 
         As the instrument was being restarted, the Isodat on the little Apple needed rebooting as well. While the machine was pumping down, the engineer was demonstrating the great features of Isodat. [Isodat has vastly improved since 1985, but still remains something most of us have a love-hate relationship with.] As we watched, I commented to the engineer that the software didn’t look very useful or straightforward to use.
         He spun around with disdain and remarked, “This is not a mass spectrometer for a housewife!”  The room was silent for many awkward seconds. The American Finnigan team looked at their shoes; Tom and Doug frowned; and I stood flabbergasted without a quick rejoinder. I wonder what I would say today in these circumstances. I am sure I would have a rejoinder now.
         Somehow, I continued to be a customer of Finnigan—now Thermo. Today’s Isodat and auto samplers can handle any and all types of analyses while the busy housewife can go home at 5 pm, cook for her family, bake bread, clean the house, and tuck her children into bed at night—all while the IRMS precisely and accurately measures isotopes in the 5th decimal place.  Thermo can now proudly say, “We make mass spectrometers for housewives!”
            At a recent AGU meeting (2016), I sat on a panel of isotope geochemists that included John Hayes, Ed Young (UCLA), John Eiler (Caltech), Max Coleman (JPL) and me. We each took a couple minutes to tell the audience about what we thought was important for young isotope geoscientists to consider. Eiler gave a strong pitch for knowing exactly how the instrumentation works, essentially saying that if you don’t understand the finer points of mass spectroscopy, you should find another line of research. John Hayes politely inserted himself and disagreed. “Without a strong scientific question to drive you, it’s not enough to get you up in the morning to do your work.” Both Eiler and Hayes have answered major scientific questions in their careers; both, technically competent. Clearly, to be an innovative biogeochemist you need to have intellectual as well as technical expertise. Having the best possible laboratory and equipment is key.
         During my career, I have set up six stable isotope laboratories, essentially from the ground up. My first major lab renovation took place in 1982 at the Geophysical Lab when it was on 2801 Upton Street. The old, ceramic-tiled lab benches were ripped out by our maintenance crew. My next step was to draw up lab plans including plumbing, electrical, air handling, and cabinetry. I was pretty proud of my effort to design a new laboratory and presented my diagrams to the Lab’s chief carpenter and plumber. He looked at them in disgust, flung them on the floor, and said he they weren’t good enough. I was crushed. My eyes brimmed with tears. I went down the hall to talk to Hoering and told him what happened. “Ah!” he said, “He doesn’t know how to read. I’ll show you what to do.” He grabbed four different colored markers, marched into my lab, and said, “Draw the lines on the walls!”
Swallowing my pride, I asked the carpenter to return to see if my plans were better this time. Lines on the walls worked. Renovations happened smoothly thereafter. I learned to never assume that people, including students, know or understand everything I do.
         Essential to purchasing the best equipment is establishing a rapport with the people who will help you fix your instruments when they inevitably break down. We refer to these godlike people as service engineers. In my 40 years in the isotope field, there have been essentially four companies making isotope ratio mass spectrometers (IRMS): Nuclide—now defunct and the only U.S. company; Finnigan-MAT-Thermo-Fisher, a German company that started in the U.S. but moved to Germany years ago; and VG-Sercon-Elementar, basically a British company that has many reiterations; and Nu Instruments, a Welsh company with a British flavor.
         My first instruments were Nuclides. For our Nuclide instruments, we personally knew the individuals who had built our IRMS and called them if there were problems. The Geophysical Lab had in-house electronics engineers, Chris Hadidiacos and David George, who designed computer systems for automating the Nuclide instruments and repaired boards and vacuum pumps. In recent years, I’ve used the Finnigan-Thermo-Fisher instruments. With Finnigan-Thermo Fisher, we worked with a United States based group of engineers. Frank Trensch led the group in the 1990s. His phrase “Isolate the variables” serves as my mantra for troubleshooting.
Chuck Douthitt and Marilyn at UC Merced: I was a #1 Customer
         When a Thermo instrument was installed, an engineer worked in your lab for two to three weeks. Roger Husted installed our 252 IRMS in 1991 and our Delta Plus XL in 1999. A taciturn man with a southern accent, Roger arrived in the morning with two cups of coffee, worked silently all day, then left abruptly when he thought the job was finished. Other engineers were often more sociable, chatting with students, going out for beers, and joining us at lunch. The personalities of engineers were well known, and it was important that you had a good rapport with the person who installed your instruments.
         Over time, Roger Husted demonstrated his knowledge and patience, and he was responsible for keeping our 251, 252, 253, and two Delta instruments in decent shape by solving the inevitable problems.
         In 2012, our Delta Plus XL was dead in the water. A faulty 24-volt power supply knocked out some of electronics at an unprecedented scale. Derek Smith, Dave Baker, Roxane Bowden, and I tried for several months to figure out what happened. At that time, it cost $6,500 a day to have a service engineer fix your instrument. There was no guarantee that they could fix it in a day. Scientists just don’t have that kind of money hanging around.
Roxane Bowden, Roger Husted, Marilyn, Glenn Piercey, Derek Smith--the multiboard fixit team
         Finally, a clandestine effort by Thermo’s IRMS salesman Chuck Douthitt and Roger Husted saved our instrument. Roger drove to DC, set out his schematics, and within four hours diagnosed our problems: the motherboard, high voltage board, inlet control board, and communication board had all been ruined by the faulty power supply! Talented engineers like Roger Husted are key to keeping stable isotope research going. Learning to troubleshoot instruments, take them apart, and fix them takes time and hands-on experience measured in years, not just weeks or months. Because isotope instruments are increasingly automated, we sometimes forget how complicated they really are.
Bill Holmes, Thermo Engineer (L) and Jon Nye, UCR 2017
         Purchasing the right IRMS for your research goals is key. At the Geophysical Laboratory, we were able to eventually find the resources from public and private organizations to keep our isotope lab fairly current. Early on we relied on American technology with the Nuclide Corporation, then switched to German technology with the Finnigan MAT-Thermo, when Nuclide slowly got out of the IRMS business. At Carnegie, we kept our instruments running for 14-20 years because we had the time to take care of them and were not required to accommodate large numbers of inexperienced users. On university campuses, professors need to rely on laboratory managers and technical experts because there isn’t enough time in the day to teach, serve on committees, do research, write grants, and maintain a lab to a high standard. Fortunately, there are many scientists who enjoy the role as “fixers” and thrive in situations that require them to spend their days with instruments. Tom Hoering used to say with regards to fixing mass spectrometers, “Show it who’s boss.” Over the years, I developed decent skills as a fixer, but working with other talented people with technical skills is an enormous help.
High School student Brendan O'Connor at GL running the mass specs! 2009
         Increasingly, many of the difficult analyses we did in the past that took days are now done automatically. Brian Fry, stable isotope ecologist, helped innovate the field tremendously by spending time developing on-line combustion methods for bulk carbon and nitrogen isotope measurements (Fry, 1992). Zachary Sharp innovated the oxygen and sulfur isotope geochemistry field with his implementation of laser fluorination. Hayes, Freeman, Robert Dias, Jeanette Jumeau and others developed the early peripheral devices for compound specific isotope analyses (CSIA) that transformed the biogeochemistry and organic geochemistry fields. Willi Brand (e.g., Brand, 20014) and Andreas Hilkert at Thermo were key engineers in Bremen, Germany, who understood the needs of the research community, saw that we had the equipment we needed, and innovated within their company. We were able to analyze carbonate samples, wood, bones, soils—you name it—with these instruments. My career advanced in leaps and bounds when I was able to incorporate one of these scientists’ inventions into my research.

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