Identifying asbestos

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rs6000
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Identifying asbestos

#1 Post by rs6000 » Mon Nov 04, 2019 7:30 pm

How do I differentiate asbestos from other items in sample I.e sand grains pollen etc I live in NV and am concerned of airborne contamination that has been documented in the news recently as being very high :shock:
I have a zeiss std 18 with a monocular polo head with swing in pol and have placed a linear pol on top of field lens,
anything else I may need.

Cheers
Jeff

MicroBob
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Re: Identifying asbestos

#2 Post by MicroBob » Mon Nov 04, 2019 9:06 pm

Hi Jeff,
to separate objects from other suff it is good to know the properties in thich the object differs from the other stuff. For asbestos this it temperature resistance in the first place. After burning organic matter the choice will be narrowed down considerably. Next come polarisation properties and refractive index.

Bob

MichaelG.
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Re: Identifying asbestos

#3 Post by MichaelG. » Tue Nov 05, 2019 12:27 am

Jeff

This is an excellent document from the UK Health and Safety Executive:
http://www.hse.gov.uk/pubns/priced/hsg248.pdf

... Pick from it what’s useful to you.

MichaelG.
Too many 'projects'

Wes
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Re: Identifying asbestos

#4 Post by Wes » Tue Nov 05, 2019 8:12 pm


rs6000
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Re: Identifying asbestos

#5 Post by rs6000 » Wed Nov 06, 2019 4:51 am

Thank you all very much for your input and the sources of Documentation I have another question on something I don't have
do I really need a red slider like the ones described they seem quite expensive for such a vintage item.

cheers

Bryan
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Re: Identifying asbestos

#6 Post by Bryan » Wed Nov 06, 2019 5:42 am

My first job out of college was a microscopist I an asbestos lab. It’s been almost 30 years since I left that job but I remember a few things. I did two different types of analysis, the main one was PLM identification using a petrographic microscope. This was for identifying asbestos in bulk samples like popcorn ceiling or asbestos insulation. I would pulverize a sample and look at it under polarized light using different refractive oils. There are several different types of asbestos and they all have different refractive indices. Once I identified fibers that looked like asbestos I would identify the type with the proper oils. I would also determine the concentration for reporting purposes, any thing over 1% is considered asbestos containing.

It sounds like you are concerned with airborne asbestos. What I did was analyze filter cassettes that collected airborne dust for a work shift. I used a phase contrast microscope to count fibers, anything over a certain ratio of length and width. There was a method we had to follow counting fibers to determine the concentration. This didn’t specifically identify asbestos fibers, it gave a concentration of potential airborne asbestos. If we wanted to know if there was really asbestos in the sample it was sent to another lab that used an electron microscope.

Unless you are in thick dust and can get a concentrated sample to view It would be very difficult to identify airborne asbestos. Bulk samples have nice large fibers to identify, airborne asbestos will be much smaller, especially if it traveled some distance to reach you. I don’t know what concentrations you have in the air but it can be a problem. Look at what happened in Libby, Montana or Asbest, Russia, two extremely bad cases.

https://www.asbestos.com/jobsites/libby/

https://www.nytimes.com/2013/07/14/bus ... habit.html

MichaelG.
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Re: Identifying asbestos

#7 Post by MichaelG. » Wed Nov 06, 2019 6:01 pm

rs6000 wrote:
Wed Nov 06, 2019 4:51 am
[…] do I really need a red slider like the ones described they seem quite expensive for such a vintage item.
The specification for the slider doesn’t seem too onerous
■ a removable first order red compensator (of retardation approximately 530 nm);

I suspect that a DIY approach would suffice.

Note: The text below Fig. 7 here is helpful:
https://www.microscopyu.com/techniques/ ... microscopy

MichaelG.
.
.

Edit: Also worth a look:
https://www.microscopyu.com/techniques/ ... efringence
The area between zero and 550 nanometers is known as the first order of polarization colors, and the magenta color that occurs in the 550 nanometer region is often termed first-order red.
Too many 'projects'

rs6000
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Re: Identifying asbestos

#8 Post by rs6000 » Fri Nov 08, 2019 7:13 pm

seems like the general consensus is quartz ,mica etc sliders are not as important as differing refraction oils
my question now becomes I did not know of anything other then the immersion oil I use for 63x and 100x objectives where do I obtain such a wide variance of oils

Hobbyst46
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Re: Identifying asbestos

#9 Post by Hobbyst46 » Fri Nov 08, 2019 7:59 pm

rs6000 wrote:
Fri Nov 08, 2019 7:13 pm
seems like the general consensus is quartz ,mica etc sliders are not as important as differing refraction oils
my question now becomes I did not know of anything other then the immersion oil I use for 63x and 100x objectives where do I obtain such a wide variance of oils
I do not know if they fit asbestos analysis, but one of the best sources for defined nD oils is Cargille (USA). Their oils are also distributed by Amazon and specific laboratory suppliers, (Sigma etc); and are priced accordingly (not for inexpensive hobby use).
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

rs6000
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Re: Identifying asbestos

#10 Post by rs6000 » Fri Nov 08, 2019 9:51 pm

WOW :o

692$ to 2K$ for 7ML :shock:
AND I thought the sliders were expensive did I go on the wrong page?

https://cargille.com/refractive-index-l ... 10b42-bb01

Scarodactyl
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Re: Identifying asbestos

#11 Post by Scarodactyl » Fri Nov 08, 2019 10:41 pm

That's for a set of over 100 ri fluid bottles with 0.02 increments. I suspect you can get by with a few of the 1/4 oz bottles for your use, though I could be wrong as I haven't done asbestos analysis before.

Bryan
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Re: Identifying asbestos

#12 Post by Bryan » Sun Nov 10, 2019 3:18 am

You don’t need anywhere near 100 different RI oils, I think I had a set of less than a dozen and there were a few out of that set that got the most use. I wish I could remember what ones we used.

Bryan
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Re: Identifying asbestos

#13 Post by Bryan » Sun Nov 10, 2019 3:29 am

Here’s some information on bulk asbestos identification. It sounds a lot like the method I used and it lists the oils that you need

https://www.cdc.gov/niosh/docs/2003-154/pdfs/9002.pdf

rs6000
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Re: Identifying asbestos

#14 Post by rs6000 » Mon Nov 18, 2019 2:59 am

Thank you VERY much I sure have my work cut out for me looks like ill have to procure 6 differing RI oils according to that document and maybe a red slider
sure wish you could borrow or rent equipment like that would make a beginner Micropisist life much easier
but no scope shop in this town!!

rs6000
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Re: Identifying asbestos

#15 Post by rs6000 » Wed Nov 20, 2019 11:15 pm

Extreme confusion
I thought I new everything about differing types of Objectives Phase,Polo Strain Free, Dark F built in Iris, TIRF specific, DIC between all but Phase maybe a slight different glass Flourite ETC but other then that most objectives all seem the same optically

well after reading through those docs I have been provided I found a confusing line or two sounded like I need a special staining RI oil
here is quoted TEXt:

Dispersion staining
A2.39 Dispersion is a term used to describe the variation in RI with the wavelength of light. Differences in dispersion between particles and liquids mean that even though the RIs match at one wavelength, they may be quite different at others. This leads to colour effects when fibres are observed in matching RI liquids using white light. It is easiest to observe small bright particles against a black background; hence a central stop in the back focal plane of the objective is used


looks like I as well need a specialized Dispersion Staining objective DS type objective one that I have never seen on any website :shock:
MY new understanding is that POLO Scopes are not for faint of heart centering nosepiece turret, quartz wedges, analyzer,First order compensator, lambda plate ;;geesh the list goes on might as well buy a DIC setup does not seem much different and you save a lot of money on all those accessories
maybe I should go to school to learn this stuff I really don't know what to do now

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wporter
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Re: Identifying asbestos

#16 Post by wporter » Thu Nov 21, 2019 10:43 pm

Another possible reference, from the esteemed McCrone Research Institute:

http://www.mccroneinstitute.org/v/90/as ... tification

Hobbyst46
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Re: Identifying asbestos

#17 Post by Hobbyst46 » Fri Nov 22, 2019 9:31 am

Here is another good reference on asbestos and dispersion, from the late R. Pavlis
http://www.microscopy-uk.org.uk/mag/ind ... rsion.html

Regardless of asbestos analysis, it seems that dispersion staining can be fun, must find time to play with it!
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

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75RR
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Re: Identifying asbestos

#18 Post by 75RR » Fri Nov 22, 2019 12:39 pm

... maybe I should go to school to learn this stuff I really don't know what to do now
Is this something that you want to do yourself or need to do yourself or is it just something that you want done, as in it does not really matter who does it?

I ask because it seems to be getting overly complicated and potentially expensive.

Perhaps if you can provide a little more background someone can suggest a more practical solution ... as in you collect the samples and send them to a Lab
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)

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