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#1
Old 10-24-2010, 08:54 PM
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What units are "GM"? This can't mean gram....

I'm looking for a chemical (2,6-Dichlorophenolindophenol) to use as a vitamin C indicator. One supplier shows it for over $600 for 25 GM. What could they mean by GM? This stuff can't possibly be $600 a gram.
#2
Old 10-24-2010, 09:02 PM
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I don't know if that means gram or not. Wikipedia listed gm as an unofficial abbreviation of gram. The chemical from your site could be some very refined stuff, thus, pricier. Here is some stuff more for your needs in case you haven't found any yet.

Last edited by feppytweed; 10-24-2010 at 09:03 PM.
#3
Old 10-24-2010, 09:06 PM
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It looks like it's about $27.50 per gram.
#4
Old 10-24-2010, 09:09 PM
Nope! I said stop!
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Quote:
Originally Posted by CookingWithGas View Post
I'm looking for a chemical (2,6-Dichlorophenolindophenol) to use as a vitamin C indicator. One supplier shows it for over $600 for 25 GM. What could they mean by GM? This stuff can't possibly be $600 a gram.
What you wrote suggests that it is $600 for 25 grams, not per gram.
#5
Old 10-24-2010, 10:15 PM
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A random example from the same site: (2S)-(+)-25-Dihydro-36-dimethoxy-2-Isopropylpyrazin, $185.74 per milliliter.

Yes, that is what it costs (with the caveats about your arithmetic that others have pointed out). You are looking at highly purified analytical reagents (and some fairly complex molecular structures, that may not be all that easy to synthesize). They don't come cheap.
#6
Old 10-24-2010, 10:29 PM
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Yep, gm means gram. Just did a quick check on Sigma-Aldrich and it is a whole lot cheaper there (~$125/25 g). You might check VWR and Alfa-Aesar as well, which are the other big chemical suppliers to see what their prices are like.

Depending on what precursors are available and their costs, complex chemicals can be time consuming and expensive to make. This is part of the reason some pharmaceuticals cost so much.
#7
Old 10-25-2010, 12:13 AM
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Also bear in mind that the material is used in very small quantities; 25 grams would make 25 liters of test solution, which is used about 1 ml at a time as an indicator, and maybe 40 ml at a time as a titrant. My practice would be to buy the 1 gram vial.

Which leads to my next point; the packaging for such chemicals is extreme; Sigma-Aldrich will charge little less for the gram than it will for the 25 g, because every bottle shows up in a plastic bag inside a can with a styrofoam liner, surrounded by a plastic bag of granular absorbent, which will in turn be inside a cardboard box full of absorbent. Or something like that.
#8
Old 10-25-2010, 03:04 AM
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I don't know about that particular item, but I once slashed the cost of yearly calibration of a colorimeter to 1/4 what it previously was; one of the reagents was a Co-Pt complex and the savings were higher than what I cost the company for a whole year as a lab tech (including benefits, SS tax, and all)...

I've seen paints that cost upwards of 4 figures per gram, and a few grams could paint many items (think metallic-rainbow-with-sparkly-glints keychains), so the manufacturer was extremely wary of any requests for "samples".

Last edited by Nava; 10-25-2010 at 03:05 AM.
#9
Old 10-25-2010, 06:47 AM
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Originally Posted by IvoryTowerDenizen View Post
What you wrote suggests that it is $600 for 25 grams, not per gram.
Good point, still seems expensive.

I've seen other sites that give a recipe for making a vitamin C indicator with corn starch and iodine. Don't know how reliable that technique is.
#10
Old 10-25-2010, 09:23 AM
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Originally Posted by CookingWithGas View Post
Good point, still seems expensive.
In comparison to what?
#11
Old 10-25-2010, 09:53 AM
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Looking at the supplier's catalogue, I see EA and PK alongside GM for the measurement unit of various products. EA = each for items sold individually, PK = package for items sold by the package. Looks like the abgreviation for their stock-keeping system leaked out into the larger world. Presumably they're selling it by the indicated quantity in grams. Though they should know to swap their in-house abbreviations for "each", "package", and "gram" (or g).
#12
Old 10-25-2010, 10:10 AM
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Originally Posted by yoyodyne View Post
In comparison to what?
Compared to name brand pharmaceuticals it is downright cheap.

I looked it up on fishersci.com and the chemical in question can be had in gram quantities for ~$25/gram. I don't know about shipping and handling though.
#13
Old 10-25-2010, 10:55 AM
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Originally Posted by yoyodyne View Post
In comparison to what?
Well, gold is about $48 a gram today, so it's a little over half the price of solid gold.

I was expecting it to be on a par with OTC medications. I have no idea what it takes to produce a chemical like the one I'm asking about. This seems to me to be a substance that might be highly mass-produced, perhaps supplied to high schools and universities, with economies of scale.

If 1 gm makes a liter, then that gives a different perspective to the matter, so it's not expensive to use. But a gram ain't much, about one or two paper clips' worth.

Pharmaceuticals might at first blush seem like a good analogy, although, which require years of R&D, clinical trials, marketing, etc. I figured an off-the-shelf chemical would be a lot cheaper.
#14
Old 10-25-2010, 11:07 AM
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What units are "GM"? This can't mean gram....

A gigameter; or about the distance from the Earth to Saturn. I'd say a line of 2,6-Dichlorophenolindophenol that stretches such a distance is a steal for $600.
#15
Old 10-25-2010, 11:25 AM
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Originally Posted by Randy Seltzer View Post
A gigameter; or about the distance from the Earth to Saturn. I'd say a line of 2,6-Dichlorophenolindophenol that stretches such a distance is a steal for $600.
[nitpick]
A gigameter would be Gm, GM is strictly speaking nonsense since there isn't any unit(at least that I'm aware of) that has the symbol "M".
[/nitpick]
#16
Old 10-25-2010, 11:26 AM
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Originally Posted by Randy Seltzer View Post
A gigameter; or about the distance from the Earth to Saturn. I'd say a line of 2,6-Dichlorophenolindophenol that stretches such a distance is a steal for $600.
Nah. A gigametre would be "Gm". Lower-case m. I don't think there's a base unit whose symbol starts with an upper-case M.

Upper case/lower case matters in SI symbols. One MW (megawatt) is one billion mW (milliwatts).

I've noticed a lot of people in technical fields who should know better are sloppy with spelling the SI symbols. Many units are derived from names of people, but now that they are units of measurement, they are not capitalized. Only some of the symbols are capitalized. For instance, the watt is symbolized W, but you don't capitalize the full name of the unit. It's "watt", not "Watt".

-Sunspace, who just finished a course that touched on permeance of vapour barriers used in construction, which in the Ontario Building Code is measured in ng/Pasm2.
#17
Old 10-25-2010, 11:37 AM
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Cocaine sells for $50 and up per gram, so that stuff is relatively cheap.
#18
Old 10-25-2010, 11:39 AM
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A GM is about 80% of a Ford.
#19
Old 10-25-2010, 12:07 PM
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Originally Posted by Mogle View Post
[nitpick]
A gigameter would be Gm, GM is strictly speaking nonsense since there isn't any unit(at least that I'm aware of) that has the symbol "M".
[/nitpick]
American engineers sometimes use M for meters, or for Million, or for Millions of dollars, or for Thousand. Cap or lowercase.

I've worked with various engineers and technical people for years and am used to seeing their half-hearted approximations. They're not very precise with their unit notation, which leads to occasional consequences.
#20
Old 10-25-2010, 01:55 PM
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Originally Posted by CookingWithGas View Post
I was expecting it to be on a par with OTC medications. I have no idea what it takes to produce a chemical like the one I'm asking about. This seems to me to be a substance that might be highly mass-produced, perhaps supplied to high schools and universities, with economies of scale.
...
Pharmaceuticals might at first blush seem like a good analogy, although, which require years of R&D, clinical trials, marketing, etc. I figured an off-the-shelf chemical would be a lot cheaper.
I'm guessing otherwise, that this substance is probably only used in a few specialized applications. A few food testing labs in industry or the FDA would definitely have use for measuring vitamin c, but my WAG is that most can now use modern analytical instruments instead of some older colorimetric assay. There are all sorts of compounds that aren't in great demand, so they're only ever produced in small quantities of a few kg. If there was a big enough market that it's produced by the ton, you'd bet there would be economies of scale.

Prices for chemicals are all over the map. I'm doing experiments with a very common biological molecule which costs $5/g for very pure reagent grade stuff. I'm also using its fluorinated analog (crudely speaking a chemically modified version designed to jam up the relevant cellular machinery) and it costs $600/g.
#21
Old 10-25-2010, 03:49 PM
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Originally Posted by Sailboat View Post
I've worked with various engineers and technical people for years and am used to seeing their half-hearted approximations. They're not very precise with their unit notation, which leads to occasional consequences.
Interesting that they refer to "US customary units." I'm American and have always heard that system called "English units."
#22
Old 10-25-2010, 03:54 PM
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Originally Posted by CookingWithGas View Post
Interesting that they refer to "US customary units." I'm American and have always heard that system called "English units."
The US Customary system is different than the Imperial system. The old English system has not been used in England since the early 1800s. Yes, you folks may casually refer to the US system as the "English" system, but after losing a few planes and space probes due to measurement errors, you can be sure that relevent authorities are being Very. Precise. about their unit names.

Last edited by Sunspace; 10-25-2010 at 03:55 PM.
#23
Old 10-27-2010, 11:52 AM
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Quote:
Originally Posted by Mogle View Post
[nitpick]
A gigameter would be Gm, GM is strictly speaking nonsense since there isn't any unit(at least that I'm aware of) that has the symbol "M".
[/nitpick]
Capital M is used to denote a solution of 1 mole per litre. So obviously they're selling a solution of this chemical with a concentration of 600 gigamoles per litre.
#24
Old 10-27-2010, 12:03 PM
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Originally Posted by MikeS View Post
Capital M is used to denote a solution of 1 mole per litre. So obviously they're selling a solution of this chemical with a concentration of 600 gigamoles per litre.
Sweet! $600 sounds like a great deal for a chunk of neutronium.
#25
Old 10-27-2010, 12:10 PM
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Originally Posted by Sunspace View Post
The US Customary system is different than the Imperial system.
Something you'd come to realize if you're a beer drinker. Bigger pints across the pond!
#26
Old 10-27-2010, 12:15 PM
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Originally Posted by MikeS View Post
Capital M is used to denote a solution of 1 mole per litre. So obviously they're selling a solution of this chemical with a concentration of 600 gigamoles per litre.
Learn something new every day I guess. But I will note that the official SI unit for concentration is mol/m3 with the symbol "c", which is why I couldn't find anything with "M" as the symbol.
#27
Old 10-27-2010, 11:02 PM
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Originally Posted by Jorge_Burrito View Post
Yep, gm means gram. Just did a quick check on Sigma-Aldrich and it is a whole lot cheaper there (~$125/25 g). You might check VWR and Alfa-Aesar as well, which are the other big chemical suppliers to see what their prices are like.

Depending on what precursors are available and their costs, complex chemicals can be time consuming and expensive to make. This is part of the reason some pharmaceuticals cost so much.
Sigma-Aldrich probably won't sell to you unless you have an account. Something about not wanting laymen buying chemicals.

VWR - I've bought blind, but it's always been lab supplies, never chemicals. Never tried buying chemicals from them.

Alfa-Aesar - no experience.

I have corporate profiles with SA and VWR. My experience has been that chemical supply companies will not sell to you without a corporate account.
#28
Old 10-27-2010, 11:14 PM
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Originally Posted by GameHat View Post
Sigma-Aldrich probably won't sell to you unless you have an account. Something about not wanting laymen buying chemicals.
I do buy chemicals from them, but always from a R&D standpoint. Their website sucks - you have to look up a chemical, then call them, then prove you're a legitimate buyer (read: established chemical company), then prove you have an account. Only then will they let you order.

And SA is never for industrial sized orders, always for R&D. You can get a few hundred grams of nearly everything but nothing on an industrial scale.

Last edited by GameHat; 10-27-2010 at 11:14 PM.
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