An accurate test for how long does nicotine stay in your system can be performed via blood test. If a laboratory is testing for nicotine, it should be performed within 3 days of smoking. It is better for a laboratory to test for cotinine as it remains in the blood stream for about 10 days after smoking.
The pH in the human digestive tract varies greatly (see Human Digestive Tract pH Range Chart on the left side). The pH of saliva is usually between 6.5 - 7.5. After we chew and swallow food it then enters the fundic or upper portion of the stomach which has a pH between 4.0 - 6.5.he pH of any solution is the measure of its hydrogen-ion concentration. The higher the pH reading, the more alkaline and oxygen rich the fluid is. The lower the pH reading, the more acidic and oxygen deprived the fluid is. The pH range is from 0 to 14, with 7.0 being neutral.
The normal pH value for the body fluids is between pH 7.35 and 7.45. When the pH value of body fluids is below 7.35, the condition is called acidosis, and when the pH is above 7.45, it is called alkalosis. Metabolism produces acidic products that lower the pH of the body fluids. For example, carbon dioxide is a by-product of metabolism, and carbon dioxide combines with water to form carbonic acid.