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Heptane, n-heptane, 95%, 99%
- Thread starter ildruido
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N-heptane means normal heptane, a seven-carbon, nonbranched, straight chain molecule. It has a single boiling point range.
Heptanes (like hexanes) refers to a mixture of isomers, some branched, having a variety of boiling point ranges.
I'd go for either of the n-heptane choices. Heptanes may have higher boiling components
which may result in residual solvent in your end product.
Heptanes (like hexanes) refers to a mixture of isomers, some branched, having a variety of boiling point ranges.
I'd go for either of the n-heptane choices. Heptanes may have higher boiling components
which may result in residual solvent in your end product.
downwardsfromzero
Boundary condition
The heptane should slowly evaporate from the product over the course of several days, assuming you got a clean evap test on the solvent to start with. If it's a bother to wait, dissolving the product in acetone and allowing that to evaporate will get rid of practically all of the heptane residue. You may well end up with goo instead of crystals however, since acetone is hygroscopic (picks up water from the atmosphere).
Your heptane is probably largely n-heptane, although it could be a narrow-range fraction of naphtha with a boiling range centred on 98°C. A close look at the label or the SDS should clear this up.
Your heptane is probably largely n-heptane, although it could be a narrow-range fraction of naphtha with a boiling range centred on 98°C. A close look at the label or the SDS should clear this up.
brokedownpalace10
Established member
Startex Xylene shows
CAS-No. Chemical Name Weight %
1330-20-7Mixed xylenes 90 - 100
100-41-4**Ethylbenzene 30 - 50
98-82-8**Cumene 0.1 - 1
on the SDS.
Do Ethylbenzene and Cumene (Isopropylbenzene?) evaporate completely?
CAS-No. Chemical Name Weight %
1330-20-7Mixed xylenes 90 - 100
100-41-4**Ethylbenzene 30 - 50
98-82-8**Cumene 0.1 - 1
on the SDS.
Do Ethylbenzene and Cumene (Isopropylbenzene?) evaporate completely?
downwardsfromzero
Boundary condition
Given enough time they will, although cumene will leave some residue of its hydroperoxide which in turn decomposes to phenol under certain conditions. The hydroperoxide could in principle contribute to the oxidation of DMT. Another of its breakdown products, 2-phenyl-2-propanol, is highly likely to be an allergen.brokedownpalace10 said:
Finally, the arithmetic of those chemical composition values is bending my brain a bit! Is it perhaps 3.0 - 5.0 for ethylbenzene?
brokedownpalace10
Established member
downwardsfromzero said:
I know, right? I figured it had to be a typo as well, but I cut and pasted it accurately.
Would that be an issue to use? Is phenol an issue? After using Naptha, it pulls a little more.
downwardsfromzero
Boundary condition
It should be fine if you extract into acid immediately after pulling. Maybe add a pinch of ascorbic to counteract the (traces of) peroxide. I'd be consider washing the xylene before use, first with ascorbic acid solution, then with saturated sodium carbonate [edit: 5% sodium hydroxide - see below], just in case of cumene peroxides in the former case and phenol in the latter.
Reading a bit more about phenol here, we can see that the trace amounts concerned are likely to be largely harmless since it occurs as a natural metabolic byproduct in humans. Still its toxicity and corrosive nature at above trace levels should not be ignored. If you can minimise an impurity, it's general best to take appropriate steps to do so.
Reading a bit more about phenol here, we can see that the trace amounts concerned are likely to be largely harmless since it occurs as a natural metabolic byproduct in humans. Still its toxicity and corrosive nature at above trace levels should not be ignored. If you can minimise an impurity, it's general best to take appropriate steps to do so.
brokedownpalace10
Established member
downwardsfromzero said:
I should have specified STB. Is there an easy way to accomplish that? What about using it for changa and water washing?
downwardsfromzero
Boundary condition
Eh, we seem to be at cross-purposes here, could you state your intentions more comprehensively from the beginning?brokedownpalace10 said:
What I've suggested is that you clean up your xylene immediately prior to use.
A mini A/B would remove phenol from contaminated DMT, but only if you use sodium hydroxide for the base stage. Sodium carbonate is not strong enough to deprotonate phenol.
The way you basify your bark is neither here nor there, although of course lye-basified material (being the usual for STB) would also pull out the phenol.
brokedownpalace10
Established member
downwardsfromzero said:
Sorry about that. I'm not a chemist, obviously
downwardsfromzero
Boundary condition
No probs, I'm not much of one either!brokedownpalace10 said:
downwardsfromzero
Boundary condition
Heptane is the official name for the 7-carbon, straight chain (unbranched) saturated hydrocarbon (alkane). The "n-" (for "normal) prefix is used to denote this since other prefixes such as iso- and neo- have been used to denote various chain-branching permutations. While this has been superseded by systematic nomenclature, the old trivial and semi-trivial names remain popular typically because they are shorter. A good example is "acetic/acetyl" being quicker and easier than "ethanoic/ethanoyl".
When it comes to the remaining 5%, firstly that's a maximum since the 95% value will be a minimum purtiy level for the heptane. Secondly, you need to check the SDS for what it might say about "residue on evaporation" or something similar. There should also be data on the boiling range. I'm not going to try to guess too hard about the purity specification for technical grade heptane, but it's likely to tie into working practices around what kinds of tank residues are acceptable during transport and storage. Isolating straight chain alkanes is relatively straightforward (from an industrial point of view) so my best guess would be that it's various methyl- and dimethyl- derivatives of pentane, hexane and heptane. Getting that last 5% out is the expensive bit!
Just be sure to do an evaporation test to see that your heptane evaporates cleanly. Think about where in the supply chain impurities may have the opportunity to enter.
When it comes to the remaining 5%, firstly that's a maximum since the 95% value will be a minimum purtiy level for the heptane. Secondly, you need to check the SDS for what it might say about "residue on evaporation" or something similar. There should also be data on the boiling range. I'm not going to try to guess too hard about the purity specification for technical grade heptane, but it's likely to tie into working practices around what kinds of tank residues are acceptable during transport and storage. Isolating straight chain alkanes is relatively straightforward (from an industrial point of view) so my best guess would be that it's various methyl- and dimethyl- derivatives of pentane, hexane and heptane. Getting that last 5% out is the expensive bit!
Just be sure to do an evaporation test to see that your heptane evaporates cleanly. Think about where in the supply chain impurities may have the opportunity to enter.