Nicotine presence can be detected in the blood for a short period only (about 48 hours) . However, its metabolite, cotinine, can be detected up to about three weeks from the last use and the cut-off detection levels is 200 ng/ml.
Q: What is the purpose of toner? Our skin is happiest at a pH of 5.5. Toner balances the pH of your skin. If you are acne prone the skin is too acidic. So finding a slightly alkaline toner can help balance the acidic nature. If the skin is dry, it is too alkaline, so finding a toner that has a lower pH can bring it to a happy balance of 5.5. Toning 1 minute after cleansing allows all the beneficial molecules to absorb into the skin as it is still wet.
The bottom line is to know where you want the mash pH. Dark malt is more acidic that pale malt. This is important to know when testing the water prior to adding the grist (grains). The pH of the water should test somewhere between 5.8 and 6.5 so the mash pH settles into that sweet spot after the grain is added. The pre-grain water should test closer to 6.5 for darker grains and closer to 5.8 for paler grains. You will need to adjust the pH to keep it in the proper range.