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 symptom index (SI) for the chief complaint of heartburn or chest pain in 100 consecutive patients referred for ambulatory 24-h esophageal pH monitoring. Note the predominance of SI values in the two extremes (77%). There was a good association between high SI and an abnormal 24-h pH test (97.5%), as well as low SI and normal 24-h pH test (81.1%). (From [19].) index should be set lower than 75%. A few patients with normal 24 pH have positive symptom index, which in itself gives valuable information.