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 :)
Showing posts with label analytical chemistry. Show all posts
Showing posts with label analytical chemistry. Show all posts
Thursday, January 04, 2007
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 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 :)
Sunday, November 26, 2006
Search for ICPMS on digg.com yields no results
I searched for "mass spectrometry" on the user powered news site, digg.com, and got no results. First, I checked under the science topic. Oh, wait there are some stories that come up when the whole site is searched.
Fairly interesting stuff, not newsworthy according to the digg community, but I don't think there are many scientist on there.
At Georgia Tech, this is what they call a nanoscale probe, or the Scanning Mass Spectrometry probe (SMS). It seems like what they are trying to do is take some mass spectrums of protiens, metabolites, and peptides without separating them from the cell/tissue. The associate professor responsible for doing this work is Andrei G. Fedorov. His research is pretty hardcore, talking about crazy ideas for ion sources, see project 7.
I think the way it works is the substrate gets a positive charge, the scanning tip has a negative charge. The scanning tip pulls molecules by charge, but also uses something called Taylor electrohydrodynamic focusing of jets to produce charged ions.
Fairly interesting stuff, not newsworthy according to the digg community, but I don't think there are many scientist on there.
At Georgia Tech, this is what they call a nanoscale probe, or the Scanning Mass Spectrometry probe (SMS). It seems like what they are trying to do is take some mass spectrums of protiens, metabolites, and peptides without separating them from the cell/tissue. The associate professor responsible for doing this work is Andrei G. Fedorov. His research is pretty hardcore, talking about crazy ideas for ion sources, see project 7.
I think the way it works is the substrate gets a positive charge, the scanning tip has a negative charge. The scanning tip pulls molecules by charge, but also uses something called Taylor electrohydrodynamic focusing of jets to produce charged ions.
Saturday, September 16, 2006
Plumbing better than Mario and Luigi
Instead of dealing with large green pipes you have to jump into,
I have to deal with peristaltic pump tubing.
These little tubes are used to carry liquids into the mass spec. Other people use them too, such as chemists who use HPLC, IC, and SFA.
About twice a month, I have to run an analysis called FIAS or TTRA. Too make a long expanation short, the samples are mixed with buffer (pH 5.5) and internal standard (Y, In, Tb) all "online", then pushed through a column with an affinity resin that grabs the transition metals and lets the group I metals pass through. Then, the column is washed with acid, which rinses the transition metals into the mass spec which sorts them and counts them.
The way the literature describes to do this was unecessarily complicated. It explained using a sample loop and employing a water line to wash the column. It involved two valves, two pumps, four peristaltic pump lines, a double six-way valve, and finally the column.That's the way I did it and it worked for a while, but eventually it stopped working properly and I couldn't fix it. So instead of spending multiple days troubleshooting, I decided to just completely start over and re-think the whole thing.
I re-plumbed it much more simple and straight forward. Both valves, half of the double six-way valve, and the water line ended up being unnecessary. Now, loads of para-film were no longer needed to prevent leaks in the peristaltic pump tube connections. Also, less sample is used.
I have to deal with peristaltic pump tubing.
These little tubes are used to carry liquids into the mass spec. Other people use them too, such as chemists who use HPLC, IC, and SFA.
About twice a month, I have to run an analysis called FIAS or TTRA. Too make a long expanation short, the samples are mixed with buffer (pH 5.5) and internal standard (Y, In, Tb) all "online", then pushed through a column with an affinity resin that grabs the transition metals and lets the group I metals pass through. Then, the column is washed with acid, which rinses the transition metals into the mass spec which sorts them and counts them.
The way the literature describes to do this was unecessarily complicated. It explained using a sample loop and employing a water line to wash the column. It involved two valves, two pumps, four peristaltic pump lines, a double six-way valve, and finally the column.That's the way I did it and it worked for a while, but eventually it stopped working properly and I couldn't fix it. So instead of spending multiple days troubleshooting, I decided to just completely start over and re-think the whole thing.
I re-plumbed it much more simple and straight forward. Both valves, half of the double six-way valve, and the water line ended up being unnecessary. Now, loads of para-film were no longer needed to prevent leaks in the peristaltic pump tube connections. Also, less sample is used.
Thursday, May 25, 2006
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_,
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_,
Tuesday, May 16, 2006
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.
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.
Thursday, May 11, 2006
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.
Wednesday, May 03, 2006
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.
Monday, April 24, 2006
DARTs and MS
I'm sure all the mass spec people have heard about this before because it is so cool and also one year old news. It's a new ionization method called DART (direct analysis in real time) invented by Robert B. Cody of JEOL USA and James A. Laramee of EAI Corp. It is a sample introduction system that can be coupled to a mass spectrometer, currently only coupled to a MS by JEOL.
The major difference here, compared to other mass specs, is the sample inlet is at atmospheric pressure. You can hold an object, such as an orange, up in front of the sample cone and get a reading of masses detected and find fungicides.
This technique works by applying an electrical potential to a gas (N2 or H2) to form a plasma that interacts with the sample and the atmosphere.
It took me a minute to picture the instrument layout in my head, I couldn't, so I went to the website. The path of the ion: First, gas is fed in, a plasma is formed, then the instrument opens up to the atmosphere. So, the open region is between the plasma torch and the sample cone. Then, the rest of the mass spec, the one they use happens to be a time-of-flight.
The major difference here, compared to other mass specs, is the sample inlet is at atmospheric pressure. You can hold an object, such as an orange, up in front of the sample cone and get a reading of masses detected and find fungicides.
This technique works by applying an electrical potential to a gas (N2 or H2) to form a plasma that interacts with the sample and the atmosphere.
It took me a minute to picture the instrument layout in my head, I couldn't, so I went to the website. The path of the ion: First, gas is fed in, a plasma is formed, then the instrument opens up to the atmosphere. So, the open region is between the plasma torch and the sample cone. Then, the rest of the mass spec, the one they use happens to be a time-of-flight.
Friday, April 21, 2006
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.
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.
Tuesday, February 28, 2006
Phosphorus and methamphetamine
A great idea, all this time, and no comments. Well, fellow mass spectrometrists of the world, I've got some new things to talk (write, type, blog) about.
Short side note, anyone ever hear a hissing noise comming from the torch box. It's not an electrical arc or I just can't see one. I have produced an electrical arc on the torch itself before and gave it a nice melted dimple. This noise seems to be something else, almost sounds like gas or water blowing out a small hose, but I think if that was the case, things wouldn't be working as well as they have been. No visible damage or drift caused by noise.
Next up, I just got word that I will be analyzing some samples from a meth lab bust. I'll be looking for phosphorus. I imagine I'll find some since the samples are taken from powder made by grinding up match heads. So, I don't think I'll have any actual meth in the lab, sorry. I know detection limits are crappy, like 1ppm, anyone know about any interferences or any other problems analyzing phosphorus.
Methamphetamine has quite a history. It's a farely new drug, first synthesized in 1919 in Japan. It was distributed during WWII to Nazi soldiers as a stimulant. In the 50's it saw such uses as a cure for narcolepsy, post-encephalitic parkinsonism, alcoholism, depression, and obesity. What a wonder drug back then. Made illegal sometime in the 80's when its recreational use started up.
Easily made by even non-chemists from pseudoephedrine hydrochloride, various different procedures found in chemistry journals or sketchy websites. There is a wealth of information found on Wikipedia (who checks the facts on this website?)
Short side note, anyone ever hear a hissing noise comming from the torch box. It's not an electrical arc or I just can't see one. I have produced an electrical arc on the torch itself before and gave it a nice melted dimple. This noise seems to be something else, almost sounds like gas or water blowing out a small hose, but I think if that was the case, things wouldn't be working as well as they have been. No visible damage or drift caused by noise.
Next up, I just got word that I will be analyzing some samples from a meth lab bust. I'll be looking for phosphorus. I imagine I'll find some since the samples are taken from powder made by grinding up match heads. So, I don't think I'll have any actual meth in the lab, sorry. I know detection limits are crappy, like 1ppm, anyone know about any interferences or any other problems analyzing phosphorus.
Methamphetamine has quite a history. It's a farely new drug, first synthesized in 1919 in Japan. It was distributed during WWII to Nazi soldiers as a stimulant. In the 50's it saw such uses as a cure for narcolepsy, post-encephalitic parkinsonism, alcoholism, depression, and obesity. What a wonder drug back then. Made illegal sometime in the 80's when its recreational use started up.
Easily made by even non-chemists from pseudoephedrine hydrochloride, various different procedures found in chemistry journals or sketchy websites. There is a wealth of information found on Wikipedia (who checks the facts on this website?)
Saturday, February 18, 2006
Message board
My original idea was to create a message board where mass spec researchers and analysts could discuss trouble shooting. I suggested it to the company which makes the mass spec I work with, but I havn't recieved any reply and didn't really expect it.
So, I'm taking it upon myself. I am currently an environmental chemist using mass spectrometry to analyze water and sediment samples for metals. The mass spec I use uses a quadrupole to filter the ions and it also has a type of collision cell that all the companies are putting out now. The collision cell is supposed to reduce interferents by colliding the interferents with other gas molecules supplied into the collision cell. It also has kinetic energy discrimination which uses some various lens voltages within the collision cell to limit the range of kinetic energies in the ion beam coming out of the collision cell.
I've got everything working pretty well after battling for 6 to 8 months. But I still have some elusive problems which is why I'm creating this blog, or message board.
Anybody analyze Arsenic in salt water with a collision cell? I can't get rid of some interferent at mass 75 which gives me a constant result of 6 - 10ppb in salt water samples that are confirmed having less arsenic by a optical method (ICP emission.) I can discuss a lot more if anybody else knows anything about this.
So, I'm taking it upon myself. I am currently an environmental chemist using mass spectrometry to analyze water and sediment samples for metals. The mass spec I use uses a quadrupole to filter the ions and it also has a type of collision cell that all the companies are putting out now. The collision cell is supposed to reduce interferents by colliding the interferents with other gas molecules supplied into the collision cell. It also has kinetic energy discrimination which uses some various lens voltages within the collision cell to limit the range of kinetic energies in the ion beam coming out of the collision cell.
I've got everything working pretty well after battling for 6 to 8 months. But I still have some elusive problems which is why I'm creating this blog, or message board.
Anybody analyze Arsenic in salt water with a collision cell? I can't get rid of some interferent at mass 75 which gives me a constant result of 6 - 10ppb in salt water samples that are confirmed having less arsenic by a optical method (ICP emission.) I can discuss a lot more if anybody else knows anything about this.
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