Australia's Science Forum

Morning everyone,

Does anyone have a substitute for Touluidione blue to test for lignin? We have no touluidine blue and want to do this test today if anyone has an alternative. Thanks.

There are a couple of alternatives in "The Laboratory", a book often discussed on this forum. If you don't have the book, I can post the alternatives for you.

just made one using this recipe:

Phloroglucinol for lignin
Dissolve 5 g of phloroglucinol in 75 ml of ethanol and 25 ml of water. Ligneous tissue should be well-flooded and staining continued for about 2 minutes after which 1 drop of concentrated hydrochloric acid should be added. Phloroglucinol stains lignin red. Bark works perfect + ve,
compare bleached paper (printing paper) -ve test, and unbleached paper (any recycled paper or paper towel) +ve test
match stick +ve

We use phloroglucinol but I already have the acid in the made up solution. Good positive is also saw dust.