The news on advice on new mass spec purchases is timely. We (at Stanford University) are now in the final stages of setting up a new stable isotope facility. The only thing missing at the moment is a mass spec(s). I have spent the better part of a year talking with many colleagues about past and present instruments they have had in their labs over the years. The decision of which instrument to purchase is a difficult one, one that should take more than a 'little' time. The analogy to purchasing a car is a fair assessment and the fear of purchasing a lemon is foremost in our minds. Funds for these instrument are difficult to acquire and some of us rarely get a second chance. All too often these instruments become the life blood of our labs and our research hangs on the success of these tools. With luck we will be making an instrument shortly. The three main vendors (Finnigan, Micromass, and Europa) make fine mass specs. The MAT 252, Optima, and 20-20 essentially have the same sensitivity and linearity. To me the difficult choice is choosing the peripheral to attach to the instrument. Here is where there is large debate. Kiel vs multiprep vs CAPS, continuous flow systems, water devices, etc. They all have their pros and cons or controversies if you wish. I have talked on the phone with a number of you on this list over the past year and thank you for all of your input. I have also read on this site about some incredible sample sizes from some of the devices out there, numbers the factory would never quote or admit they could reach with these peripherals. Only recently are the manufactures saying they have broken the 10 microgram barrier with carbonate systems (i.e., Kiel III and multiprep). For example, take the isocarb or autocarb device from both Finnigan and Micromass. There are lots of these systems out there attached to Delta's, SIRA's, Optima's, Prism's, and the like. What I have found out from my reading and discussions with many of our colleagues out there, is a technique that works in one lab doesn't necessarily mean it will work in another (even given the same instrumentation). Different amounts of acid, varying acid surface area, sample boat design, sample spillage prevention, different run times, pump time, special source tuning, the list is endless. On the negative side, this information is confusing and can complicate the decision making process for a lot of colleagues out there. I know it made me dig deeper to acquire more details about the these various peripherals. But, on the positive side it demonstrates that given time you can find what works best in your lab and push these instruments and peripherals to the limit. Don't get me wrong, I am not suggesting that there is misrepresentation going on, I am just pointing out that all instruments and peripherals are not created equal. Over the years I have been able to keep a SIRA24 online and old VG602's at spec with lots of TLC. Something all mass specs require either from the get go or as they age. In the labs I have worked, I have gone to length to minimize the effort required to obtain samples off-line. I am looking forward to the pros and cons of adding automated analyses to the new lab. We must keep in mind that these instruments are not plug and play. To expect that, you are going in on a purchase wearing blinders. And yes, I know some of you have had installations blessed by the mass spec gods and others cursed. My experiences over the years have been with Europa and Micromass/VG. I have had good relations and service from Europa while my dealings with Micromass have been mixed but favor on the positive. My experience with Finnigan has only been on the sales end when the lab at South Carolina purchased the SIRA24 in 1982 and recently. To learn more about Finnigan, I have to rely on our fellow colleagues out there, and learn from their experiences. The final choice we make will essentially be made over who gives us the best package for the dollar. I feel that given time all of the instruments out there will do the job well. All of the sales reps I have worked with over the past year have put in a good effort to present to us a 'best' deal. If anyone is interested in the information I have acquired over the month wrt the three mass spec vendors, feel free to contact me. Those of you interested are welcomed to come visit our new facility at Stanford University once it is online. Cheers, David Mucciarone **************************************************************************** David A. Mucciarone Stanford University Department of Geological and Environmental Sciences Stanford, CA 94305 -Temporarily at Rice University- (713) 527-4880 (O), (713) 285-5214 (F) Geology: x-2356 e-mail: [log in to unmask] WWW: http://pangea.stanford.edu/~dam ****************************************************************************