Any interest in determining nicotine--by DVAP

[DVap]

Ah, DVap meant a larger current spread over a longer/larger coil then, rather than a hotter temperature due to higher current?

Precisely.

6 volts through a regular atty (assume 3 ohms) is going to be pumping 2 amps.

3.7 volts through a redesigned atty with more thermal mass (maybe 1.85 ohms) is also going to be pumping 2 amps.

The difference is that 6 volts accomplishes it with heat, while 3.7 volts through a redesigned atty accomplishes it with less heat, but spread over a greater surface area.

Still waiting to see if vaporer sees something wrong in my reasoning on this.

[kinabaloo]

Precisely.

6 volts through a regular atty (assume 3 ohms) is going to be pumping 2 amps.

3.7 volts through a redesigned atty with more thermal mass (maybe 1.85 ohms) is also going to be pumping 2 amps.

The difference is that 6 volts accomplishes it with heat, while 3.7 volts through a redesigned atty accomplishes it with less heat, but spread over a greater surface area.

Still waiting to see if vaporer sees something wrong in my reasoning on this.

more heat (in the new atty design) but similar temps

Hi voltage without (hopefully) the meltdown

[Vaporer]

Actually, I rebuilt my DSE601 pipe atty with 32ga wire not 36ga for exactly that reason.
It has the same ohms, draws the same current but has a greater heating surface to work from. Works very well too. It has to heat slower due to its greater mass.

There are always variables like coil wetness, airflow that changes it all.
I answered DVap with a constant set of values that show a baseline.
There are rpobably 10 variables that can be tossed round that will cause significant changes. No one said 3.6v was an ideal voltage/wattage combo. it's what the manufacturers got us started on.
The center of the coil , the point of a short circuit, is actually where the heat begins and no doubt is hotter than the rest. On short bursts at least.

Even at 3.7v we are exceeding what is needed to vaporize.

[Vaporer]

I have a pic here of a coil I made that is conical (point up). The theory being that even wickless, it leaves very little surface for the atomized liquid to miss. So, it's more efficient at the same power levels. It deformed slightly before enough oxidation formed and shorted out, but was working well. I have a pic if you'd like to see it.

[kinabaloo]

Actually, I rebuilt my DSE601 pipe atty with 32ga wire not 36ga for exactly that reason.
It has the same ohms, draws the same current but has a greater heating surface to work from. Works very well too. It has to heat slower due to its greater mass.

There are always variables like coil wetness, airflow that changes it all.
I answered DVap with a constant set of values that show a baseline.
There are rpobably 10 variables that can be tossed round that will cause significant changes. No one said 3.6v was an ideal voltage/wattage combo. it's what the manufacturers got us started on.
The center of the coil , the point of a short circuit, is actually where the heat begins and no doubt is hotter than the rest. On short bursts at least.

Even at 3.7v we are exceeding what is needed to vaporize.

Yes, for a fast heat up time. Temperature control could avoid overheating, lessen 'burning', allow batteries to last longer, and probably attys too (Temperature control of the atomiser heater coil).

Yes, the conical shape is a nice idea; seem to remember we discussed this before. Later, I decided that direct juice feed would be even better (juice constantly ready and in coil contact).

[DVap]

Now that I think about it, whoever said it's not voltage or current but the combo of the two (power or watts) hit the nail on the head.

The standard atty (assume 3.5 ohms) with standard 3.7 volt battery, 3.9 watts.
The same atty at 6 volts, 10.3 watts
A more massive atty at 1.8 ohms with a couple parellel 3.7 volt batteries: 7.6 watts

[DVap]

On a slightly different topic, and one that's actually quite in line with the DIY e-liquid forum, I've had several folks ask me lately about how making a tobacco extract in propylene glycol to flavor e-liquid might contribute to the nicotine content of a finished e-liquid.

There are several points to consider, and I'll cover them one by one.

1. The extraction itself.

If I were doing this, I'd want to use 10 mL of propylene glycol per gram of tobacco to be extracted. The choice of tobacco would be an additive-free tobacco since a lot of the tobacco available is stinking with additives, humectants, and who knows what else. The nicotine percentage of the tobacco won't be that important (which will be demonstrated later). For the purposes of this post, I'll say we're using a strong additive-free Virginia tobacco at 3% nicotine. I would weigh out maybe 100 grams of tobacco, make sure it's finely divided, and place it in a clean 2 liter glass bottle with a fairly wide mouth. I would add 1 liter of USP propylene glycol, seal the bottle and shake for ten minutes or so (then let it sit a day or two). The goal here is not to extract nicotine, but to extract the tobacco flavor. We'll get some nicotine, but again, it won't much matter how much nicotine actually comes out.

2. Filtering the extract.

The wet tobacco is going to be able to hold quite a bit of propylene glycol, so the liquid will need to be separated from the tobacco solids. The first thing I would do after the solids settle out a bit is to pour off and collect the supernatant liquid. I would then place portions of the wet solids on an inclined cutting board and squeeze it out into a wide, shallow bowl using something high-tech, maybe a rolling pin. I would combine the supernatant with the liquid that's been rolled out and filter it through a couple layers of clean gauze, just enough to catch the larger particles. The extract is now filled with very small particulate that needs to be filtered. I would use a 1.5 liter or larger büchner flask in combination with a büchner funnel and filter paper circle sized to match. I'd probably experiment to get the filter paper porosity that would give me the extract clarity desired. Finer porosity takes longer (perhaps much longer) but catches more fine particles. The büchner flask/funnel combo requires a vacuum source to speed the filtration and I would either use a small vacuum pump or a water aspirator.

3. Nicotine and tobacco alkaloids in the extract.

We're assuming we used a strong 3% tobacco here, and we'll further assume that the extraction recovered all the nicotine from the tobacco. This isn't going to be the case, but it gives an upper boundary for the possible nicotine content of the extract. In this extraction we used 100 grams of tobacco and 1 liter of propylene glycol. This gives us 3 mg/mL as the upper boundary (the absolute highest concentration possible) of nicotine and tobacco alkaloids present in the extract. From here on, we'll just ignore the other tobacco alkaloids and assume the upper boundary is 3 mg/mL nicotine in the extract.

4. Nicotine contribute from the tobacco extract to the final flavored e-liquid.

Let's say we want to use 1 mL of the tobacco extract for every 10 mL of the flavored liquid and we're making a PG based liquid and our target nicotine concentration is 24 mg/mL. I'll say I'm using Chris' 40 mg/mL unflavored concentrate as the major nicotine source. To make 10 mL of 24 mg/mL flavored liquid, we'll need to make sure the total nicotine content is 240 mg in the 10 mL (240 mg/10 mL = 24 mg/mL). We start by adding 1 mL of the extract (3 mg nicotine), then we add 5.925 mL of the 40 mg nicotine concentrate (237 mg nicotine), then we add 3.075 mL of USP propylene glycol (0 mg nicotine). Now we have 240 mg of nicotine in 10 mL of finished liquid, 24 mg/mL.

5. Variability in extraction of nicotine from the solid tobacco.

What happens if we use a much lower nicotine tobacco, say a 1% tobacco. Or what if the propylene glycol extracts the flavor and fails to extract any nicotine? We're looking at the lower boundary now, which is clearly zero. So lets see how this affects our finished flavored liquid:

1 mL of tobacco extract (0 mg nicotine), 5.925 mL of the 40 mg/mL concentrate (237 mg nicotine), and 3.075 mL of USP propylene glycol (0 mg nicotine). So we have 237 mg of nicotine in 10 mL of finished flavored liquid, or 23.7 mg/mL, we're at 98.75 percent of our target nicotine concentration in the finished flavored e-liquid. We'd probably simply use 1 mL of the extract, 6 mL of the 40 mg/mL nicotine concentrate, and 3 mL of propylene glycol to assure a 24 mg (or negligibly higher) finished flavored e-liquid.

Conclusion:

The nicotine contribution from a tobacco extract in propylene glycol to a finished tobacco flavored e-liquid is negligible.

[kinabaloo]

DVap - have you had a chance to look at the report i linked above?

Wondering if any of the unsual finding in the vapor (such as biphenyl) could be indications of nicotine degrading and/or reacting in the atomiser.

[DVap]

DVap - have you had a chance to look at the report i linked above?

Wondering if any of the unsual finding in the vapor (such as biphenyl) could be indications of nicotine degrading and/or reacting in the atomiser.

I'm having trouble finding your link.. repost?

Biphenyl seems much more likely as a contaminant than a reactant. I can't see nicotine, which is based on pyridine and pyrrolidin, is going to spit out biphenyl under any circumstance or condition.

[Tom09]

link.. repost?

I share kina’s interest for an expert view on the latest report, link here. This report gives GCMS data for samples optained in three different schemes: 1.) recovered fraction of normally produced vape absorbed on charcol; 2.) volatiles outgassed from liquid at 120ºC; 3.) volatiles outgassed by heating one complete e-cig set at 50°C.

Results show a number of peculiarities which I’d like to understand a bit better. For instance (1.), the charcol extract. Where is the glycerin, would nothing absorb on charcol? Is the finding of „probably adiminothiourea" something real or pattern matching running wild? Where could it come from, if correct, what are the possible implications? Much more questions than answers in this report.