The Vespiary

The Hive => Chemicals & Equipment => Topic started by: Rhodium on February 15, 2003, 12:59:00 PM

Title: Is this LAH still good?
Post by: Rhodium on February 15, 2003, 12:59:00 PM: (https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000408236-file_znh2.jpg)

This is the label from a Merck LiAlH₄ can (it's a sealed tin can with a rubber "safety valve" which hasn't blown), but I have no idea how old it is - is it possible to find that out using the batch number, or the look of the label?

I can buy more of these cheaply, but I don't want to spend any money on possibly worthless reagents, and its too much of a hassle to titrate reactive stuff like LAH...
Title: Do a reduction of a not-that important ...
Post by: yellium on February 15, 2003, 03:23:00 PM: Do a reduction of a not-that important nitrostyrene and see if yields are OK.
Title: type
Post by: GC_MS on February 15, 2003, 05:18:00 PM: The font makes me think of a Merck product from the late 70s and 80s, even begin 90s. I think that, in order to preserve the LAH, it should have been kept away from moisture. I have some old LAH cans (about 10 years old) which still worked when using them. But they had been stored properly as well... I guess you don't know for sure untill you really test it.
Title: Contact Merck...
Post by: calcium on February 15, 2003, 05:23:00 PM: A phone call to Merck should get the age of that batch #. Traceability is a big part of the reagent game.
Title: lah
Post by: allalone on February 16, 2003, 03:56:00 AM: How does the material appear? Has it formed into hard chunks/clumps or is it still powdered? What is the color? Is the color uniform?
Title: I think it is from late 80s or early 90s.
Post by: demorol on February 16, 2003, 06:03:00 AM: I think it is from late 80s or early 90s. I have a bottle of potassium carbonate with the same label as yours, and it is dated February 1989.

You should try to reduce some nitrostyrene, as Yellium has already suggested. But use an excess of your LAH, since you don't know if it is still good.
Title: I haven't opened the hermetically sealed tin...
Post by: Rhodium on February 16, 2003, 07:54:00 AM: I haven't opened the hermetically sealed tin can yet, so I haven't been able to check what the contents look like. But you are probably right, I should perform a real-world test of it to judge the quality rather than trying to find it out beforehand. Thanks.
Title: Minimum 10 years old
Post by: Nemo_Tenetur on February 16, 2003, 11:02:00 AM: The label states the zip-code "8011". In the year 1993 we switched to 5-digit zip-codes, so it must be pre-1993.