10 posts / 0 new
Last post
Dave Finster, Wittenberg University
Offline
Last seen: 8 years 4 months ago
Joined: 08/04/2008 - 6:38pm

Magnetic susceptibility balance

I am writing up a "wish list" for my inorganic chemistry lab.  I seek advice.  Johnson-Matthey has the magnetic susceptibility balance (MSB) that seems like "the standard" for educational lab.  Can anyone advise on getting the "Mark I" vs. the "Auto MSB?"  Also, do you know the approximate prices for each of these two instruments? 

The relevant URL is:  http://pureguard.net/Library/data_sheets/MSB_Brochure.pdf

 Thanks.

 Dave

 

Maggie Geselbracht, Reed College
Offline
Last seen: 1 month 2 weeks ago
Joined: 11/17/2007 - 11:00am

Dave,

I have the Johnson Matthey Mark I Balance for my teaching lab.  I have students make different paramagnetic metal acac complexes, Cr(acac)3, Mn(acac)3, Fe(acac)3, and Cu(acac)2, and they determine the magnetic susceptibilities using both the Johnson Matthey balance and by the Evans NMR method.  Both methods work well on these complexes.  I don't have any real complaints about this balance except for the expense of the replacement tubes.  And every year, I seem to lose one or two tubes.  I am not sure if the "extra" features on the Auto MSB balance would be worth it.  Probably depends on what you intend to do with the balance.

Michael Lufaso, University of North Florida
Offline
Last seen: 3 weeks 6 days ago
Joined: 08/02/2008 - 11:00am

I also have the Johnson Matthey Mark I Balance.   I'm not sure if it is appropriate to list the cost in this forum, so I'll write that in 2007 the Mark I was halfway to five digits in USD. E-mail me if you want a more detailed price.

 Maggie is correct that the fragile tubes are the only consumable expense. Anticipate that a couple tubes will be lost or broken per year (~$25/ea).  I don't know much about the Auto MSB, so I can't provide any additional information. 


Randall Hicks, Wheaton College
Offline
Last seen: 6 years 6 months ago
Joined: 03/26/2008 - 8:34pm

Hi Dave,

I have the AUTO balance in my lab, which was used this semester for the same experiments that Maggie describes. In my experience, both work equally well. I haven't tried to use all the features, but the main differences (that the AUTO continually auto-zeroes and corrects for the empty tube reading in the sample measurement) haven't been that useful. I don't know about price differences of the models, but I wouldn't pay much extra for the AUTO for these extra features.

Sibrina Collins, The Charles H. Wright of Museum of African American History
Offline
Last seen: 2 years 5 months ago
Joined: 01/17/2009 - 10:29pm

Hi Dave,

I have a similar balance and will need to buy some replacement tubes.

Sibrina Collins, PhD College of Wooster

Sibrina Collins, The Charles H. Wright of Museum of African American History
Offline
Last seen: 2 years 5 months ago
Joined: 01/17/2009 - 10:29pm

Are you purchasing the tubes from Alfa Aesar? These tubes are expensive!

Sibrina Collins, PhD College of Wooster

Karl S. Hagen, Emory University
Offline
Last seen: 12 months 3 days ago
Joined: 11/23/2010 - 9:00am

I had our machine shop build a new sleeve for our Johnson-Matthey MSB (vintage ~1989) that has an opening large enough for a 5 mm NMR tube.  These are much cheaper than the "official" tubes, specially if you are cutting down a tube whose tip has been broken by a clumsy student or professor. Although you need more sample than the narrower diameter tubes that come with the balance, this is not normally a problem for labs such as the synthesis of M(acac)3.

Carl Jacob Ohrenberg, University of North Georgia
Offline
Last seen: 4 months 3 weeks ago
Joined: 02/06/2018 - 4:12pm

I am preparing to teach Inorganic Chemistry Lab for the first time ever on our campus.  Not only do I have to set up the lab equipment but I also need to figure out which experiments to perform.  I was planning on doing an experiment with wthe evans method and magnetic susceptibility.  Can you provide details on the acac experiment that you mention.   I would greatly appreciate it. 

Anne Bentley, Lewis & Clark College
Offline
Last seen: 1 week 4 days ago
Joined: 04/01/2008 - 8:09pm

Carl,

I've used the M(acac)3 synthesis at both the general chem and inorganic levels.  It's included (as #12) in Girolami, Rauchfuss, Angelici's book of inorganic chemistry lab experiments. I'd be happy to email you our local version.  We've had good luck with a number of different metals.  The results are very colorful, and it's been a popular lab.

This past fall, two of my inorganic students made some M(acac)3 complexes and had good luck with the Evans method. (Sealing the tiny capillary tubes to go inside the NMR tubes was probably the best part.)  Adam Johnson's LO was very helpful in learning how to approach our data analysis.  In the past, we've had our students grow single crystals for XRD analysis.  If you have that option, HIlary Eppley's LO about crystal growing techniques is very useful.

We also have a new type of learning object on the site - the syllabus LO.  You can check out my inorganic lab course here

Feel free to shoot me an email with any questions, or post them here. Inorganic lab has become one of my favorite courses.

-Anne

PS I think I have successfully embedded all sorts of links into this message.  Here's hoping they work.

Sabrina G. Sobel, Hofstra University
Sabrina G. Sobel, Hofstra University's picture
Offline
Last seen: 3 weeks 1 day ago
Joined: 05/01/2012 - 9:56am

I've used the MSB-1 as well, to determine the percent paramagnetism in the copper(II) acetate dimer. My frustration is in loading the sample into the tube, and getting it out again, drying the tube for the next use. Tubes are expensive, and hard to work with. Otherwise, the MSB-1 has worked well, reliable and holds calibration. It was about $20K a few years back.