Sciencemadness Discussion Board - best option for analysing chemicals in home lab

best option for analysing chemicals in home lab

nleslie321 - 31-10-2019 at 05:38

So im looking to spend no more than $5000 on a system to analyse compounds both liquid and solid. Im looking at Raman spectrometers, IR and mass spec.
Which is easiest to learn how to use and affordable? im looking at used items on ebay etc. Im just going into my second year at uni studying chemistry. Any help would be great thanks.

teodor - 31-10-2019 at 07:07

There are possible several options but I doubt your question has an answer. There is no such thing as "best option" just because nobody ever defined what should be goals for "home lab". Everybody has its own. If you would ask "how you do analyse chemicals" I would say I use methods from old books like Treadwell and Vogel because they don't require special devices and very educative for hobbyist (like base properties of compounds, interesting personal notes from authors etc).

Sulaiman - 31-10-2019 at 07:22

My chemistry is low level hobby stuff so I may be completely wrong, but,
I think that you should make use of University facilities for analysis of complex organic structures etc
use wet chemistry, TLC, column chromatography etc. for personal use.
Analysis equipment is developing rapidly (e.g. hand held xrf, Lab on a chip etc.) and dropping in price even more rapidly,
so you could waste a lot of cash if you buy now.
Also, learning 'old school' analysis techniques could prove very educational.
Unless you are staying at home whilst studying you also need to consider transport and security of your expensive equipment.

Using (or at least trying to use) University equipment will also help you get to know proffesors, tutors, ongoing projects, possible euipment disposals etc.
Remember, more often than not, its who you know ...

Praxichys - 31-10-2019 at 09:14

Having thought about it, I suggest the following analysis tools in this order by a mix of cost and usefulness:

Beginner lab:
pH paper (pH) $5
Thiele tube, capillary tube, thermometer (melting point) $25
Analytical balance and class A volumetric pipette (density) $400
Porcelain crucible, burner, stand (ash content, hydration state, inorganic analysis) $40
Burette, indicators (titrimetry) $150
Student microscope (crystallography) $400

In the beginning your main tools are qualitative visual analysis, density, melting point, boiling point, ashing to assess volitile/nonvolitile content, crystallography, and titremetry which is arguably the most powerful tool. You can make indicator papers and solutions to detect certain things visually, or rely on precipitation, drying, and weighing for quantitative analysis. The analytical balance is key.

Labware here can be inexpensive, requiring only basic stuff like beakers, flasks, a hotplate, some stoppers, and tubing.

Intermediate lab:
Melting point apparatus (melting point) $150
TLC plates, chamber, developer, solvent (organic analysis) $300
Polarimeter (chirality) $200
Refractometer $100 (index of refraction)
Visible light spectrophotometer, cuvettes, indicators (spectrophotometry) $800
Muffle furnace (ash content, hydration state, inorganic analysis) $400

As you build the lab, a major milestone happens when you gain a spectrophotometer which allows you to titrate far more accurately. This combined with TLC and a matching column opens doors for precise organic synthesis, the efficacy of which may be checked using polarimetry and refractometry in addition to the TLC. A melting point apparatus and muffle furnace allows the beginner lab techniques to be performed much faster and more accurately, albeit at higher cost.

This level comes with a huge cost in preparatory tools like heating and stirring mantles, a rotavap, vacuum systems, specialty apparatus, ground glass apparatus, and a fume hood.

Advanced lab:
FTIR, GC/MS, HPLC, AAS, bomb calorimetry, etc.

If you happen to have tens of thousands of dollars to spend, these tools become a possibility. The FTIR sort of sits in the middle of intermediate and advanced depending on the model, the age, and the capability you need.

Your labware might include reactors, a shaker hydrogenator, an inert atmosphere glovebox, tools for airless chemistry, etc.

Dr.Bob - 31-10-2019 at 10:25

Finding any working Mass Spec for $5000 would be a miracle, but a great deal if so. But without the LC part, it is very limited. And the maintenence and parts cost for a MS are insane.

A simple HPLC found at a unviersity surplus store or on the web might be easier to cob together and make work. Most UV detectors can be made to work with modern data collection tools to create a crude plotting tool and integrate peaks. If you can find one with working software. even better, but not hard to find something for it.

A simple MP apparatus is cheap and easy to find used. And TLC chamber with a UV lamp, and a few chemical stains is fairly cheap and easy. The UV and Raman systems are good for simple pure compound identification, if you have the right rference books and tables, but very hard to use on mixtures.

A balance and volumetric flasks are handy to determine density, along with other "density" type tools (found for wine, beer making, antifreeze, or honey testing.)

I can get you a nice home NMR for about $500,000 if you can move it...

Praxichys - 31-10-2019 at 10:44

For mixtures, use TLC, then scrape off the eluted fractions and extract them for FTIR/UV-vis or other analysis. If you get wide plates and use a line rather than a point, you can pretty easily get into the 20-30mg range for most fractions.

Steam - 31-10-2019 at 13:15

It really depends on what it is you are actually doing in the lab. For synthesis, If I had to pick just one piece of equipment, I would definitely the FTIR. Mainly because I am most familiar with IR, but it is also very versatile both for solids and liquids and if you get an ATR module, sample prep is next to nothing. However, if you have mixtures or inorganic samples, IR is pretty poor at resolving them. For mineralogical samples you will be best served by the raman over the IR.
That being said, raman and IR go hand in hand with analysis. Often times, peaks which are resolvable in the IR will be quite strong under raman.

Mass spec is nice to have but honestly, I have gone years without using it. NMR is also very nice to have- but even the desktop picospins will run you quite the pretty penny.

If you are doing inorganic chem looking at ligands, a UV/vis spectrometer can go along way.

RogueRose - 31-10-2019 at 16:44

Quote: Originally posted by nleslie321

So im looking to spend no more than $5000 on a system to analyse compounds both liquid and solid. Im looking at Raman spectrometers, IR and mass spec.
Which is easiest to learn how to use and affordable? im looking at used items on ebay etc. Im just going into my second year at uni studying chemistry. Any help would be great thanks.

There are a few places you can find working HPLC / GCMS for sometimes REALLY great prices and they are usually industry standard devices like older HP machines. There are a few auction sites that specialize in this type of stuff especially from old universities and state/federal labs. I've seen some older, larger setups sell for $300-500 b/c they were 20+ years old.

Message me if you want more info

Praxichys - 1-11-2019 at 04:28

I kind of wonder if something like this is worth it to the amateur lab:

https://www.vernier.com/products/sensors/gc2-mini/

Ubya - 1-11-2019 at 06:05

Quote: Originally posted by Praxichys

I kind of wonder if something like this is worth it to the amateur lab:

https://www.vernier.com/products/sensors/gc2-mini/

well this is interesting, i didn't know something this small existed, but for 2k i think it is quite possible to find an old used CG system (even though it would need external gas tanks and would be waaay bulkier)

tshirtdr1 - 2-11-2019 at 02:02

The one piece of equipment I use most is our infrared spectrometer. It is mainly useful for organic samples, but you can get a quick, easy, rough estimate of your success. Additionally, this machine doesn't require a lot of additional gases, etc, to run so there's basically no maintenance cost. Of course, you will need a computer to run it, so make sure it has a computer or at least comes with the software and license key. The license can be tricky as it may not be legal if you aren't the original purchaser of the equipment, but on older stuff, you can usually install it at least. The ATR accessory is nice because you don't need to insert the sample in salt plates or make a pellet. Just throw it on the machine. We use this all day long.

S.C. Wack - 2-11-2019 at 03:23

99% of the time, labs don't include the software and obsolete computer that still-working equipment was on, usually because they are under the impression that the license is not transferable, even when it explicitly is (e.g. chemstation).

G-Coupled - 2-11-2019 at 06:13

ATR?

Steam - 2-11-2019 at 18:27

Attenuated Total Reflection- sure beats nujol mulls and KBr plates!

I would fathom a guess that like 90% of all labs which causally use FTIR on a regular basis will use ATR. It is just so convenient!

https://www.azom.com/article.aspx?ArticleID=5958

G-Coupled - 3-11-2019 at 00:10

Quote: Originally posted by Steam

Attenuated Total Reflection- sure beats nujol mulls and KBr plates!

I would fathom a guess that like 90% of all labs which causally use FTIR on a regular basis will use ATR. It is just so convenient!

https://www.azom.com/article.aspx?ArticleID=5958

Looks groovy. Thanks. :cool:

It's a shame that nearly all the older analytic gear needs so much in the way of expensive gases, parts and/or maintenance.

RogueRose - 4-11-2019 at 15:14

Quote: Originally posted by nleslie321

I found about 10 HPLC and GCMS that are up for auction at a company I've been doing business with for at least 8 years (they are great!) and bids are starting at $400 for a complete setup. I think the auction ends on Wednesday, so you need to act quick. I'm sending you a message, please respond to me ASAP and I'll give you the details about the site. You need to register wtih the site to bid at the auction. I have a long relationship with a private pickup/packing & shipping company that will do all the work to ship it to you, or if you are near Rhode Island, then you can pickup yourself (woonsocket I beleive - where CVS makes all theri generic products - A VERY big Biotech sector)

G-Coupled - 4-11-2019 at 16:11

That's cool - I envy anyone who manages to aquire one of those. :cool:

It's quite amazing what one can buy for oneself these days.

RogueRose - 5-11-2019 at 06:25

Either way, you guys should check this out, it's pretty interesting. I wasn't sure I beleived it would do what they touted it would do on some TV shows (customs inspections of various mysterious chemicals) but I think it uses raman spec.

https://www.thermofisher.com/order/catalog/product/FIRSTDEFE...

https://www.fishersci.com/shop/products/thermo-scientific-fi...

It'd be really nice if someone would happen to leave one behind somewhere while traveling with no return address on it. I'd feel bad for a while but I'm guessing it'd be insured at $62K!