Check out Notre Dame's ICPMS lab

This place looks pretty sweet, except for the exhaust tubes hanging all over the place. If they analyze samples for free, can I sub-contract?

The Element 2 High-Resolution ICPMS is from the good ole boys at Thermo, who have now merged with Fisher Scientific to form a massive company that can sell you anything from post it notes to 1-Aryl-2-Pyrrolidinones. With more resolution like this, you might be able to tell the difference between 32S-33S and 65Cu. Did you know that there is a lot of sulfur in seawater, but not a lot of copper? Makes it hard to analyze for copper. Oh ya, mass 63 doesn't work either because of ArNa :)

The Golden Run

Last night's run was what we analytical chemists call a golden run. This means that all the analytes that I needed to analyze for, for each sample, had the yellow highlighter run over them on the cover page of the lab report. The yellow highlighter means that the result is good to go and I don't need to reanalyze. This has only happened one other time in the year I have been running the mass spec.
Talk about staying steady, the mass spec was on point for at least 12 to 14 hours. Now, sales people for mass specs say their instruments can stay "in cal." for like 2 or 3 days. What they don't tell is they are analyzing nice clean pretty sample in D.I. water. Get some real samples in there with loads of salt or suspended solids and your instrument might not make it past the first sample like that.

In the lab_,

Busy as Hell

Sometimes you're waiting around for the chemistry to happen, but I haven't been. It goes like this, I run the mass spec everyday which includes first, turning it on. Sometimes the plasma flickers, arcs, and starts melting the torch. This pisses me off, and it pisses my boss off because they are over $300 bucks. I still use them if they didn't melt all the way through.

Then, I move on to "optimizing" the "signal." This consists of aspirating a "tuning" solution and looking at a real time graph of "intensity" vs. time. And basically, you just move some voltages around to create high intensity of what you want, while creating low intensity for things you don't want.

Getting mid-way throught the morning now, I need to find some time to review the run from last night and prepare all the data in a type of lab report. The best time to start this is right after I start the calibration. I usually see some drift during the first calibration, so I restart it right about lunch time, so the lab keeps working while I'm off the clock.

Getting back from lunch, I have to quickly check the calibration and find some samples to run because there is no point in even thinking of running any samples until I know the instrument is going to work right. So I type in a sample sequence, make sure the QC is kosher, and then start making dilutions for pretty much everything but freshwater samples.

Now it's about 4pm and I have to finish reviewing yesterdays data, make any solutions that need to be made, and deal with email. Then I just schedule the MS to shutdown when it's done, which is usually between midnight and 3 in the morning.

Copper in seawater

This is the worst analysis ever, it's called Time Transient Resolved Analysis (TTRA) or Flow Injection Analysis of Seawater (FIAS). The methods are the same, they remove the salt from the seawater so I can measure the concentration of copper. The problem is the flow, there are two pumps, two valves, four lines, a 5mL loop, column, and six way valve, and the flow has got to be steady. A simple calculation reveals 7 to the 10th ways for it to screw up.

I have to use a bunch of para-film to keep the tube joints together because the pump builds up so much pressure in the peri pump tube to push everything throught the column.

The sample flows through a tube, mixes with a buffer (the whole shabang is pH sensitive), and flows onto the column. The metals, including copper and sodium, stick to the resin in the column. The column is rinsed with water, supposedly, the sodium washes off. Then the column is rinsed with diluted nitric acid and the copper comes off and goes into the spectrometer. The metals binding strength to the iminodiacetate resin in the column depends on pH.

Mass Spec at home?

There is a reason why you can't have a mass spec at your house. It's not because it's so big, it's because they cost so much to fix. I had a service technician come out the other day and his visit to fix one part for one day was a cool $25,000. Ya, thats just to fix it. You could buy a pretty nice house for what they can cost new.

Parts break all the time, and you can't just keep running it like a car, a mass spec has to be fully optimized at all times to work properly. The technology is always pushed to the furthest point. If old designers of mass specs stuck with the original design and just improved on it, like a clothes washer, maybe they could last 30 years. But, then it would have run off of DOS.

The picture is not me or the mass spec I run, that thing is huge. And whats with all the multi-colored lights.

Plasma goes out

So I'm just calibrating the mass spec after getting it nicely optimized and out of nowhere, the plasma goes out. That basically means I have to start all over again. I could not find a reason for it to go out. The software that runs the instrument just gave this generic error that it displays anytime anything goes wrong. The software has more bugs than Windows 98.

It's not just pushing buttons all day folks, these things happen all the time. At least half my job is troubleshooting. Finding out why the mass spec is doing what it is doing. So, like a computer, I turned it off and then back on, and everything was fine.

MS at PittCon

Well, I didn't get to go to PittCon, even though it was only a 4 or 5 hour drive from here. And it looks like I missed out on a lot of cool analytical instrumentation as well as possible job leads.
My favorite company Thermo (read with sarcastic tone) introduced a new type of mass spec. In fact, they claim it is "the first totally new mass analyzer to be introduced to the market in more than 20 years." It is called the LTQ Orbitrap mass spectrometer. To read about its initial research, Anal. Chem. 2000, 72, 1156.

Apparently, the orbitrap takes the place of the quadrupole to separate the ions based on m/z. The orbitrap "has ions spinning around a carefully shaped central electrode while shuttling back and forth over its long axis in harmonic motion at frequencies dependent only on their mass-to-charge ratios," says R. Graham Cooks of Purdue University.
More interesting news from PittCon to come.

Bismuth

Interesting facts about Bi, mass 209 (the only stable isotope), atomic number 83.
It melts at 520 F, maybe possible in the oven.
It boils at 1833 K (2840 F). The ICP plasma I use is 8,000 - 10,000 K.

Not quite as toxic as other elements in the same group, arsenic and antimony. Bismuth is used in cosmetics. And it's in Pepto-Bismol

The most diamagnetic metal, a weak type of magnatism compared to ferro- or paramagnatism. It wouldn't stick to your fridge.

It is used as an internal standard, it is run through the mass spec with every sample at the same concentration, and I make sure the instrument gives the same result. One way to tell if the instrument drifts.
Around $8 / kg.