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Author: Subject: Home Made Analysis gear
Chemosynthesis
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[*] posted on 12-4-2014 at 13:42


Quote: Originally posted by aga  

Currently i'm thinking along the lines of :-
Freezing point
Melting point

I could have sworn someone at least started their own meltemp apparatus here, but can't find the post.

http://www.chemicalforums.com/index.php?topic=50619.0
https://www.sciencemadness.org/whisper/viewthread.php?tid=22...
https://www.sciencemadness.org/whisper/viewthread.php?tid=16...

Those would be useful. A meltemp can't be all that hard to make. If you had a small camera with the temperature and sample in frame, you could leave it to slowly run and get fine measures.

Wouldn't be as cheap as a Thiele tube, but much more time convenient.
Quote: Originally posted by aga  

I found this to be excellent, and should help you to get your Milling machine cutting metal :

http://littlemachineshop.com/Info/getting_started.php

A first task would be to mill a straight slot in a piece of aluminium or brass (they're soft, so tolerate mistakes better and are less likely to snap your tooling).

Wow, thank you! Maybe I can get it out of storage this summer. I am very appreciative!
Quote: Originally posted by aga  

I do not feel that i will be able to avoid annoying people, as i do drink, think and post.

As new ideas crop up (in my mind) i find that sending them out as-is for discussion works well, as people react, flame, argue, and contribute.

So, best if i do not post anything further.

I hope you reconsider. Between your machining and electronics skills, packetforger's analytical chemistry education and background, and Etaoin Shrdlu's programming abilities, I was very hopeful for some extremely insightful experimentation.
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packetforger
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[*] posted on 13-4-2014 at 05:27


Once my exams are done or I get some time to transcribe and redraw diagrams, I will see if I can sketch out some decent representations of how some of these machines work at a fairly basic/conceptual level.

If a variable-wavelength UV source could be found (i.e. one where we can accurately control the wavelength emitted) and a detector which can identify both wavelength and intensity, a fairly simple UV absorption spectrophotometer could be constructed, which is *very* useful with a set of known standards for determining the concentration of an unknown material (although, in many cases titrimetric determination is more accurate!). Identification can be also aided by finding the peak absorption ranges on the spectrum of a compound.

Similar in principle is the IR Spec. Now, I have seen two varieties of these in the lab. The first, the one I like using the most, you simply place the sample on the "crystal" which has been cleaned by wiping with acetone, press down the "cover/crusher thing" (I don't know the term for it, we called it the "arm"), and clicked on "scan" on the computer after running a background.

I suspect that a homemade one would have two sample areas, one for a "blank" (container containing only the solvent), and the other containing a solution of your target material. The blank's peaks would be factored out, and the "true" IR absorption spectra of the compound recorded on a graph for further identification. IR is great for spotting functional groups (determining if its an alcohol or a ketone or an aldehyde, etc), and generates a "fingerprint" that can be used to identify a previously known compound based on libraries of such.

Edit: Obviously, the only massive obstacle here is the variable wavelength sources and detectors. Fix that problem and we have a winner.

[Edited on 13-4-2014 by packetforger]
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Mildronate
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[*] posted on 13-4-2014 at 09:01


you can build mercury polarograph. But actualy you need analitycal balance for real analitys chemistry, its also posible to build autotitrators and other stuff.
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[*] posted on 13-4-2014 at 10:31


Mildronate is correct, one of the more important tools at your disposal will be an *accurate* analytical balance that can weigh down as far as 4 decimal places with an incredibly high degree of accuracy.

Not to mention, ensuring you have it placed on a decent surface is equally important as a mass-dampener. The ones in one of the labs in college are not exactly the best positioned, and other people working at said area can throw your readings off by a significant amount. For example, someone leaning on the surface your balance is working on can alter the perceived mass the balance is detecting, etc.

Ideally you would place your balance on top of a big, solid lump of something heavy. A solid wooden table with some weights on it or a big slab of stone or something.
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ScienceHideout
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[*] posted on 13-4-2014 at 15:44


In my experience, the most important analytical device in the lab is the analytical balance. You must buy these... For the home analytical chemist, milligram capability is important; tenth milligram is better.

The most useful spec for the home chemist is probably the UV/Vis. I own one of these that works fine, except for the computer connectivity which is being worked on so I can do scans. Honestly, you can probably build one of these, or, at the very least, use a whole bunch of LEDs instead of a monochromator.

The most useful spec for organic is the IR. It is easy to use, and will analyze almost anything with a couple presses of a button. I want one of these, but they are super expensive.

Gas chromatographs are used to separate mixtures of liquids/gases. I am actually building one of these and it will be complete this summer, when I will post a set of instructions on the forum. Many GCs are connected to a mass spectrometer... sorta useless to most home chemists, but could come in handy. They are advanced...

HPLC is similar to GC. You can probably build one by connecting a column to a UV/Vis spec and a flow cell... Never tried it.

Flame ionization seems to me, to be one of the most useful specs... and pretty cheap on ebay. Unfortunately, They are huge and I doubt I can fit one in my lab.

NMRs are cool, they measure how the molecule reacts to radio waves, and that will show all the hydrogens in the molecule. That means, though, that your sample must be dissolved in a deuterated (expensive) solvent, or else you will be in for a surprise! Also, these are out of the question for home chemists. Not only will they demagnetize all the credit cards in a large radius, but they cost upwards of $100K, often around 250-500K.

I think the most amazing instrument, and I have been intrigued by it ever since I have used it, is the EDAX spectrometer... THese are amazing! The only problem is it has to be connected to an expensive microscope :(




hey, if you are reading this, I can't U2U, but you are always welcome to send me an email!


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kavu
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[*] posted on 14-4-2014 at 01:40


You can get these new low field tabletop NMRs with permanent magnets and a flow cell. With some savings the price range is actually within the reach of an amateur. Check out for example http://picospin.com/

[Edited on 14-4-2014 by kavu]
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Lambda-Eyde
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[*] posted on 14-4-2014 at 01:54


Benzylchloride1 also has an NMR, an old permanent magnet from Hitachi iirc.

Quote: Originally posted by ScienceHideout  
IMany GCs are connected to a mass spectrometer... sorta useless to most home chemists, but could come in handy. They are advanced...

What? In addition to IR, I can't think of anything more useful than GC/MS!




This just in: 95,5 % of the world population lives outside the USA
You should really listen to ABBA
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Mildronate
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[*] posted on 14-4-2014 at 05:00


But what do you want to analyze? There is full of old equipment around the world. Why to build some? If i ever will build GC, I will use real GC parts! but i doesnt need it, because I working with GC and HPLC.
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[*] posted on 14-4-2014 at 06:07


i have worked before on trying to build a mass spectrometer to me thats the holy grail of analytical instrument.
However ity requires deep vacuum and very god ion source and magnetic field it might be easyer than it sound with all the new electronic replacing the old ,parts could be purchased cheap or home made without costing thousands...




Http://www.d-radlab.com/
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[*] posted on 14-4-2014 at 11:13


Quote: Originally posted by Lambda-Eyde  

What? In addition to IR, I can't think of anything more useful than GC/MS!


To be completely honest, when we are talking about liquids, I can't think of one thing a GC-MS can do that an IR can't... Mass spectrometry is so much more difficult to use and interpret, they are more expensive, and they take up so many more resources. If you give me an unknown mixture of 2 liquids, I would pop it in the GC, condense the condensate, then IR it... :D




hey, if you are reading this, I can't U2U, but you are always welcome to send me an email!


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aga
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[*] posted on 14-4-2014 at 13:02


Quote: Originally posted by Chemosynthesis  

I hope you reconsider. Between your machining and electronics skills, packetforger's analytical chemistry education and background, and Etaoin Shrdlu's programming abilities, I was very hopeful for some extremely insightful experimentation.


Ok. I was just pissed off with the initial responses.

It is very hard to be enthusiastic when the Enemy Fire starts before you even leave camp.

However, the responses Since are brilliant !

It's also My thread, seeing as i started it, and i should defend it, given that the Idea is to make an Affordable Analysis Machine, and that You People have the knowledge to make it work.

I've ordered some stuff off ebay to build a 'monochromator' which in principle is rather simple, and found two 523nm lasers in a drawer.
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The Volatile Chemist
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[*] posted on 14-4-2014 at 13:03


A little while ago, I devised a system to tell the frequency of emission of light, specifically IR or visible, with two or more DIFFERENT light sensors. For example, a CdS photo-resistor, and some other type that overlaps the range of CdS are used to measure light output (Strength, as with all photoresistors and (Extremely!) cheap sensors). These two sensors have a range of how well they pick up certain frequensies, which is commonly published. With two bell curves from this data, we can find which frequency is being emitted by finding what the strength readings are for each sensor in a given situation.

And have you checked out EPR?
http://en.wikipedia.org/wiki/Electron_Magnetic_Resonance
For example, do I have CuCl2? It emmits an EPR, but I don't know how hard such a machine would be to build.

[Edited on 4-14-2014 by The Volatile Chemist]




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[*] posted on 14-4-2014 at 13:08


Another interesting factoid is that the 10Ghz range of frequencies are useful in excitation and analysis.

This immediately sprang to mind :
http://www.qsl.net/pa3gco/zelfbouw/blauwkap/bluecap.html

Basically the LNB part of a cheap satellite setup contains very high frequency amplifiers, and an oscillator at 10Ghz, plus two (Horizontal & Vertical) precision antennae, plus two amplifiers as well.

It all comes in a neat, and frequency tuned, aluminium case as well.

Cost = 16 euros here for a modern Sony version, which i took apart and found that it can also be modified.

[Edited on 14-4-2014 by aga]
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[*] posted on 14-4-2014 at 13:29


Quote: Originally posted by kavu  
You can get these new low field tabletop NMRs with permanent magnets and a flow cell.


Amazing. I was doing some research into the Magnetic Field Strengths required for Mass Spectrometry and 0.35 Tesla came up.

Seems a permanent magnet can possess such a field, and if not, Halbach arrays, or even spheres can be employed.

The AA batteries in this TriCorder are going to get hammered.
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[*] posted on 14-4-2014 at 13:32


Quote: Originally posted by neptunium  
i have worked before on trying to build a mass spectrometer to me thats the holy grail of analytical instrument.


Please elaborate. It could be that one of the stumbling blocks of a previous attempt of yours can today be simply solved.

Certainly Electronics advances faster than money leaves my pocket.
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Etaoin Shrdlu
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[*] posted on 14-4-2014 at 13:36


Quote: Originally posted by kavu  
You can get these new low field tabletop NMRs with permanent magnets and a flow cell. With some savings the price range is actually within the reach of an amateur. Check out for example http://picospin.com/

[Edited on 14-4-2014 by kavu]

That is a beautiful thing.
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[*] posted on 14-4-2014 at 13:42


Quote: Originally posted by The Volatile Chemist  
A little while ago, I devised a system to tell the frequency of emission of light, specifically IR or visible, with two or more DIFFERENT light sensors. For example, a CdS photo-resistor,


I have a feeling that Cadmium Sulphide cells will not be sensitive enough.

Personally i am thinking more along the lines of USB webcams (or similar) which are generally CCD, cheap, and sensitive to both visible and IR spectra if you remove the IR filter.

[Edited on 14-4-2014 by aga]
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[*] posted on 14-4-2014 at 13:59


You can use various derivatives, paper or thin layer chromatography and a pc/flat bed scanner or possibly an Android cell phone to do do quantitative analysis:

http://www.sciencemadness.org/talk/viewthread.php?tid=5991

There's a copy of Vogel's in the forum library which will explain the techniques in great detail :cool:




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The Volatile Chemist
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[*] posted on 15-4-2014 at 06:50


Webcams are a great Idea! Not perfect, but possibly any digital camera would work! I have an old one (Battery case broke, but when you plug it in, it's fine), so I'll experiment with removing filters. Does anyone know where I could find find a tutorial of how to remove the filter. I know what aga said works, because I saw an instructables article once about making a thermal camera out of a digital one. Obviously not perfect, but it would work.

I have a fire sensing diode, an IR sensor painted black. I got it a while ago, but I wonder if such IR sensors would work, or if we could paint such a camera black to get the same effect for a camera.

If we get this working w/ a camera, TSView (Software) would be perfect. Import a BMP you took from the camera, use the pseudo color function to bring out differences, etc. or just make a program to get the average pixel value to find out an average frequency. It'd be a start at least.




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confused
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[*] posted on 15-4-2014 at 07:11


any webcams that can do uv as well as visible light?
If so, a uv-vis spectrometer could work

Volatile Chemist:
http://www.instructables.com/id/Making-a-Night-Vision-Webcam...
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The Volatile Chemist
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[*] posted on 15-4-2014 at 08:28


Quote: Originally posted by confused  
any webcams that can do uv as well as visible light?
If so, a uv-vis spectrometer could work

Volatile Chemist:
http://www.instructables.com/id/Making-a-Night-Vision-Webcam...

A few people have stated they can do IR and obviously they can do visual. It seems reasonable they could do a bit of UV too, but not much, and it's likely there'd be no way to filter visual spectrum out from it.
Good Idea though! When I get home from school, I'll take apart my old digital, and see what I can do in the means of filter removing :)




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[*] posted on 15-4-2014 at 23:51


Right now i'm waiting for delivery of the components to make a Raymen analyser based on Radagast's work, with an idea i had for the monochromater, and a camera module as the detector.

The mel-temp part could use the same camera, and will be a block of aluminium with a hole in it for the capilliary tube (some basic machining required) and a soldering iron 50W heating element + temperature control circuit.
The block of ali should help make the temperature changes smoother.

I like the thin-film chromatography idea as well, seeing as it could also use the camera, measuring the speed & distance at which bands separate.

Any clues as to the Length of the thin film section ?

Would two slides clamped together be long enough ?
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[*] posted on 16-4-2014 at 03:24


Quote: Originally posted by The Volatile Chemist  
Quote: Originally posted by confused  
any webcams that can do uv as well as visible light?
If so, a uv-vis spectrometer could work

Volatile Chemist:
http://www.instructables.com/id/Making-a-Night-Vision-Webcam...

A few people have stated they can do IR and obviously they can do visual. It seems reasonable they could do a bit of UV too, but not much, and it's likely there'd be no way to filter visual spectrum out from it.
Good Idea though! When I get home from school, I'll take apart my old digital, and see what I can do in the means of filter removing :)


Check into Wood's glass. It filters out visible spectrum bandwidth and passes UV.
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[*] posted on 16-4-2014 at 06:02


How you guys ever worked with real MS or NMR? There always is many problems, homemade NMR or MS its not reality. And there is always classic methods for molar mass determination like cryoscopy or ebuloscopy, refraction and other more useful in home, first try basic and then think about MS. How often you need MS? I working on GC with MS, but i use more often FID for analysis. I also had HPLC at work with MS-MS, but if i can i chose FDD, use MS only for amino acids quantitative determination.
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[*] posted on 16-4-2014 at 17:58


Slightly off topic but still relevant:
http://benkrasnow.blogspot.com/2011/03/diy-scanning-electron...

He's also done freeze-drying, super critical CO2 extraction, a CT scanner, and much more.

Check out the YouTube channel he has. Amazing to watch and he brings it down to a level even I can understand.
https://www.youtube.com/user/bkraz333
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