Naphthalene black

[fibreweb]

One of our teachers is doing some fornsec stuff and has asked for Naphthalene black.

I have never heard of it but from Google I discover it is used to detect blood in latent fingerprints.

Does anyone near Tamworth have any or can anyone make any suggestions for a substitute to detect blood in fingerprints.

Thanks

Wendy

[Jazz]

what is the point? you cannot use blood.
I guess you could use luminol or you can do this experiment
http://www.sciencebuddies.org/science-f ... p072.shtml

[Robb]

Hi All,

Luminol is your best bet. At least Luminol will pick up traces on amino acids in your skin oils.

Place inferprints on Chromatography paper and they will turn Purple.

Cheers,

Robb.....

[fibreweb]

They are planning to use blood associated with a fresh cut of meat which is no different then a dissection.

But where would I get Luminol?

Wendy

[Robb]

Hi All,

Any Chemical Supplier will be able to source this for you.

Ask for 3-Aminophthalhydrazide. (Luminol)

Cheers,

Robb.....

[dime]

Hi Wendy,
I have got napthalene black. I am coming over Friday after school, so could bring it then. If you need it before I could send it with a teacher who lives in Tamworth. It is only a small vial of 25g but I imagine a little goes a long way. It has never been used in the 18 years I have been here.

[coxy]

Just curious, if the product hasn't been used in the 18 years you have been working there, why do you still have it??? I don't mean to sound rude, but why would you keep something that hasn't been requested in all that time?

[smiley]

Oh come on! Because you might use it one day, and whaddya know? Here's the proof!

[dime]

That's it Smiley. Just might come in handy. Besides it is only a small container, not taking up much room. I think I could throw out 95% of the chemicals I have got here, as they haven't been used in my time. I scaled back quite a few years ago only keeping three jars of each but keeping the selection. Think of how quick the stocktake would be without 'em all

[fibreweb]

Hi Dime,

I'd love some of it.
I'll ring you later today to work out how I will get it.
There are chemicals we havent used in my 10 years but I know as soon as I get rid of one, someone will ask for it!

Wendy

[sunray18]

Why would you keep something for 17 years??
Ask my HOD!
I even have things in cupboards that nobody knows what they are or what they do - but I am not allowed to throw them out.
I was ruthless with most chemicals and disposed of nasties.. but HOD will not let me throw out any of the indicator powders we have [some were made by Peking Chemicals-now how can you get a manufacturer's MSDS for that!] At Last count I have 8 bottles of phenolphthalein, 15 of methyl red, 6 of methyl orange, 7 of litmus, and YES I have naphthalene black! I have some, as well as naphthalene black, that NO ONE has asked for in my 11 years working here... but I am not allowed to dispose of them..
AND I also have naphthalene - now 'we may just need that one day'!
oh dear!

[dime]

It seems that the science lessons and experiments have been dumbed down, for whatever reason, probably OH&S. But the variety and fun has gone out of some of it. But I had a teacher that used to use Napthalene or more exactly moth balls. I think he used to melt them or something like that. But that experiment hasn't been done, probably not necessarily because of inherent dangers but because it is not in the current text book. And all the newbie teachers only know to follow the text book. So in reality I really could get rid of 95% of the chemicals. But then there is a specially built storeroom for them, so they are not really in the way. The only advantage would be a very quick stocktake and a bit less to clean, but then I wouldn't have Napthalene Black for Wendy. I have been sorely tempted over the years to toss 'em but......

[coxy]

Oh well, must be me. I discreetly dispose of anything not used in 4 years, and nobody ever seems to request it again. I also delete it from my stocklists and remove any MSDS sheets I had. However, we have a new HT who "apparently" likes the less is more idea. I am quietly hopeful some time this year he may approve of more chemicals leaving our store room - not that I would have more than 20 x 500ml containers of anything I could remove, but I am excited that even they may be allowed to go. As for stuff in store rooms, when taking him on a guided tour he just looked, but occasionally asked "why do you have so many....?" or "why are they still here?" Once again, I am hopeful!
Anyhow good luck with the next stock take.

[merilyn]

From a reliable source in NSW Police Forensic Training I have found that Naphthalene Black is now called Amido Black. It is used for enhancing fingerprints in blood, not detecting blood in fingerprints, so substituting luminol would not have the same effect.

[fibreweb]

The prac in question was taken from a very old text book and was in fact about enhancing blood in fingerprints.

Thanks to Dime I got hold of some of the Naphthalene Black and made up the solutions from the book. These were the instructions to make up the solutions
solution A - Naphthalene Black, Acetic acid and methanol
Solution B Acetic acid and Methanol
Solution C Acetic Acid and water.

I started off with concentrated solutions, which worked well, then reduced the Acetic acid to 80% and substituted metho for the methanol so it could be used by year 9 and it still worked.
I had a great afternoon playing with the stuff. Luckliy we had looked at cut long bones that morning so I had a great source of blood to make the fingerprints.

I also got Luminol From Annett at Calrossy so am now playing with that.

This is the bit I realy enjoy about the job. Playing to get things to work.

Wendy

[RosalieM]

Can't wait to hear the final outcomes of the prac! I hope the kids and teacher/s appreciate the work (and play!!) that has gone into preparing the prac

[lizzieb]

Good for you, Wendy - sounds like fun!

[RosalieM]

Hi Wendy! I know this is going back a while, but do you still have the prac method you used for this?

[DavidPeterson]

We did the same exact prac about 10-11 years ago, and I couldn't find any napthalene black in my stores, so I substituted it for Eriochrome Black T (aka Solochrome black).

Worked perfectly - in fact I still have my test fingerprint!