TheHomeScientist - 2010-02-24
Testing for the element boron using curcumin, a yellow dye we extract from the spice turmeric. With curcumin, boron forms an intense red complex called rosocyanine, which allows boron to be detected at very low concentrations in water, soil, and so on.
thank you that was well explained and very helpful!
this is really good :)
HA! Mark 1 eyeball! good stuff!!
I can't express how happy I am to find this video, especially since my group will be testing the presence of borax in food in a few days. I am curious, however, with the procedure that we will be using. Why do we need to add Ammonium Hydroxide and HCl to the curcumin paper after it gives off a reddish hue?
I want to extract the Red complex, is it stable enough to use it as a dye for plastics?
i found 3 tons of sheep wool in an abandoned factory nextdoor, its 20 30 years old and in fine conditiotn so i need to test it for borax treatment. ill see if i can test direct on the wool. thanks!
Hi Robert, I live in Indonesia, food manufactuers add boric acid to food here for various reasons. I just found out that is not healthy. Your video will allow me to figure out which food has this. Food labeling in this environment is not reliable. Thanks so much for sharing. Awesome.
Nice
Nice video
Is rosocyanine toxic?
My tincture turned greenish, when putting soil and perfume (EtOH+PlantOils+Ether) in it. Wondering if that reaction has a meaning too..?!
hey have ur book i even found some errata i emaikled u through ur site though i was wondering if u tested positive for boron can u get it out? cheers
i am no scientist but i do enjoy watching your videos and somewhat learning about this stuff. I have no clue what it all means but it is interesting to me :) You do a very good job
Can this test be used to determine boron levels in anthracite coal, or shale? And if so, what would the procedure be?
I just performed this test according to EPA standards (which called for boric acid) and nothing happened. Can I use grocery store Borax for my standards?
Drop the base, and it will turn red ;)
Nice test... one question... I happened to have some boric acid i'd made up a month back or so... mixed it in with water mixed in the turmeric directly and no color change was noticed... so i went to the laundry room, grabbed the borax and sure enough red. Is the limitation due to the acidity of boric acid vs sodium tetraborate? or is it due to how they dissosciate differently in solution? Have you tried boric acid?
Would the test work to detect borosilicate glass ?
I wish I was knowledgeable enough to contribute a relevant comment about this video. Your videos have inspired me to take more chemistry classes at my university. I look forward to more.
I like curcumin
Robert, well i just added some baking soda to the mix and nothing happened... so i added more.. added until saturated. nothing. Forgot how slowly the boric acid disolves in cold water. went out to the shop and upon my return the baking soda had all been used up. added a bit more and saw the change. So my guess is that the boric acid is only miscible and not soluble? but naw all acids are soluble right? the reaction occurs when the boron forms a complex ligand? something like the dissosciation of Cu2SO4 in citric acid. so reading wiki it states that boric acid will form polyborates just above pH7... is that what would be expected of Na2B4O7·10H2O as is disolves?
RBT, did u notice the Exponential color change was not what you might expect for the 4th well compared to the 3rd well, the 4th well seams darker than the 3rd. can you explain or hazzard a guess as to why, its unlikely it was the camera as all the other well's showed a nice discernible difference.
I did notice that - my guess would be because an imperfect droplet method was used, either each drop was a different size, or the solution obtained with the pipette wasn't fully mixed. Because of that, it was good that 8 wells were used instead of one or two.
I'm curious to test samples to better understand if the presence of boron exists in stones. Would this test work with dustfalkes from the stones?
WARNING.. This experiment is wrong. The strong color change is due to the curcumin coming to contact with the alkaline solution. It is not making the curcumin-boron complex at all. Please try it with Sodium Carbonate (not bicarb) instead of borax and you will get the same results. Look at journals for the real method which always requires acidic conditions and a solvent. Boric acid using this guys method gives no color either, again showing that the color has nothing to do with boron but with pH only. Bad chemistry and useless chemist at work.
WRQ Nine - 2017-01-21
Thank you for such a simple and available "solution" to the subject of boron detection.