[Limpet Chicken]

Hello again, your friendly neighborhood mad scientist reporting

Could anyone solve this little problem for me, I need an inorganic acid that is reasonably obtainable, and has a low molecular weight, which must be below the weight of a sulfate group?

Halogen atoms need not apply  

[Donaldson Tan]

Hydrobroric acid? I'm not sure about its availability

[AWK]

HCl

[ssssss]

Nitric acid HNO3

[jdurg]

HCl

Ummm.. Cl is a halogen there AWK.  

ssssss; HNO₃ is NOT an easy acid to get ahold of.  It's toxicity, reactivity, and propensity to form explosives makes it VERY highly regulated.  

[Limpet Chicken]

The amounts of HNO3 I would need for my experiment wouldn't be a problem at all, I'm not too sure on the toxicity of nitrate salts in small amounts though, houldnt be a problem though, as I am only working with amounts of salts about 500mg total at the most

I don't think boron compounds are at all suitable for my purposes due to toxicity.
Thanks for the advice on HNO3, I might go with that

The acid group needs to preferably have a GREATLY lower molecular weight than either HCl or sulfate groups for my experiments.

[jdurg]

It's not really the nitrate ion in HNO₃ that leads to its toxicity.  It's the fact that when nitric acid reacts, it tends to give off nitric oxide fumes which are pretty toxic and nasty things.  If you've ever noticed how bottles of nitric acid tend to turn yellow after a while, that's because of the acid decomposing into NO and NO₂ vapors.  (The NO oxidizes to NO₂ upon exposure to oxygen gas).  Those vapors are really nasty things and can start side reactions which you may not be expecting, nor wanting.  (That is also why nitric acid is supposed to be isolated from everything else.  It's an incredible oxidizer).  So just remember to do any HNO₃ experiments in a VERY well ventilated room.  

[Mitch]

NO_x are some of the nastiest gases I've ever had to deal with. I'm freaked just thinking about it. I remember having to use it once in p-chem lab.

[Limpet Chicken]

I was referring more to oral toxicity of organic nitrate salts, the gases/vapours of HNO3 aren't going to be a problem because I have at least a reasonably quality of gas mask, and am upgrading to full military grade full face mask soon

Still, what would be THE lightest possible acid to use for my experiment?
This one is giving me a pain-in-the-ass headache trying to work it out at 2.10 in the morning lol,

I was thinking, wouldn't the permanganate salt be lighter than sulfate?
although I am not too keen on either A: making too much permanganic anhydride at once, or B: the general oxidising nature of permanganic acid/permanganates,
Would permanganic acid (not anhydride) be sufficient to destroy alkaloids?
I don't want to mess up an expensive experiment

Actually, I think the gas that I worry about most that I have worked with is HF, I have no experience as yet with elemental F, but hydrogen fluoride for some reason scares the shite out of me, I just get VERY nervous on the rare occasion that I have to use it.

[jdurg]

Heh.  You should be scared of HF.  The fluoride ion is incredibly toxic, and although a small amount is good for the health of your teeth, anything more and you're bordering on the nasty toxicity of the ion.  HF is more nasty due to the F^- ion than it is the acidity of it.  It's actually a weak acid, but for human beings it's incredibly vile.  

[Corvettaholic]

I don't think a military grade gas mask will protect you from nitric acid fumes. I asked that a while ago and got that idea shot down, cause I happen to have a military grade mask (cause i'm in the military) and it operates using activated charcoal. I don't that will stop fumes, and if it does I think it'll still eat through the rubber portions of the mask. Which is most of it.

[Limpet Chicken]

I already HAVE a mask that is listed as being able to protect against acidic gases, I meant that I wanted the military full face mask for when I have the inclination to work with things that are well....military on nature, the filter on my existing mask protects against acidic gases and the like, but I have had nasty experiences with chloroacetone, acrolein and xylyl bromide due to it not having full eye protection.

The fumes of HNO3 are not really going to be a problem, if there are no better ideas, and I choose to use HNO3 for my experiment, I will only be working with about a 10% concentration, all it has to do is form a salt with an alkaloid, so I doubt if fumes/burns will be much a problem so long as due care is taken.

[Corvettaholic]

What kind of filter is rated to acidic stuff? I want one. I thought you were going to use the same concentration of nitric acid that I was planning to use when I gave some thought to guncotton. Good thing I didn't do it though, because I'd probably be missing hands today.

[Limpet Chicken]

I can't remember what the filter is, the guy that sold it to me was rather strange about selling it to me for some reason. All I remember is that the filter definately protects against the halogens, and acidic gases, unfortunately, the only failing is that it doesn't stop NH3 getting through which is a pain in the ass.

I need a new mask that protects against the more unpleasant of agents, for my experiments with OTC methylating agents :')