Liakoyras

Hi!
As a vaper, I have found that the market is very 'loose', with no kind of regulation at all, and I decided to start researching about what I vape.
First thing, of course, is the easy one: nicotine concentration tests on e-liquids.
I decided, though, to purchase the ingredients locally, for many reasons - paranoid customs officials in my area being not the least of them.
I have a few questions for you:
1. I found Bromothymol blue in the powder form. I was told that the solution should be made with 0.05% Bromothymol powder and the rest distilled water. Is this ok? If I make it much denser, will there be a problem? (I don't have equipment to accurately measure weight. I use a cheap digital scale with 0.1gr precision, but I know its readouts are not precise).
2. I think that using an even less denser sulphuric acid solution, like let's say 0.06%, can lead to even more accurate results, since the inaccuracy associated with the 0.1ml marking will be cut in half. Is there a reason for not using that much thinned solution?
3. I purchased Sulphuric Acid at 96% concentration (nothing less at the local market, sorry). I will make a much less dense solution for making the tests, about 1 gram in 830 gram of distilled water to be close to the 0.12% you are using.
The problem is, of course, derermining the actual concentration of the solution. If I know it, I'll be able to decide the number needed for multiplication , to determine the actual nicotine content.
Can you tell me a way to determine the concentration of that Sulphuric Acid solution? Is there an alkaloid product on the stores, with standarized pH, to make a test using the Bromothymol blue so as to find that concentration?
Alternatively:
I'm thinking of thinning it in 3 steps, using e.g. 10 percent of the solution in each step with 90% distilled water.
So it should be:
Step 1: 90gr water, 10gr Sulphuric Acid 96% -> 9.6% solution
Step 2: 90gr water, 10gr Sulphuric Acid 9.6% -> 0.96% solution
Step 3: 90gr water, 10gr Sulphuric Acid 0.96% -> 0.096% solution (which is a number close to the 0.12% you are proposing, and so little changes have to be made to the calculations. If I use 10.76% and 98.24% I will end exactly at 0.12%).
I believe that using my cheap digital scale, I can achieve 0.2gr in 100gr precision. So, with 2% inaccuracy in each step, the total inaccuracy will be a bit less than 6% (and the final solution will be somewhere between 0.090% and 0.102%). In a 24mg liquid, the results should be between 22.59mg and 25.47mg - and on a 6mg one, between 5.65mg and 6.37mg. That's enough precision for me.
The question here, is: Is this correct? Did I forget something fundamental - or trivial - that I should take into account? Is there a practical consideration I don't know, or a mistake in my assumptions or calculations? Perhaps Sulphuric Acid's molar mass or density should be used somewhere?

And, finally: why not put the Bromothymol blue in the sulphuric acid solution, so that only one bottle will be needed for the test?

I hope that all these are clear and understandable, since english is not my native language and I'm not a chemist.
I also hope that you don't hold hard feelings for not purchasing the supplies from you
Finally, I hope that this post will be noticed and replied soon...

Best regards from (tottering at knife's edge) Greece!