Food Types, Dietary Supplements, and Roles
Chuong Pham-Huy, Bruno Pham Huy in Food and Lifestyle in Health and Disease, 2022
The pH is a measure of the acid-base balance of a solution or a water. The pH (potential Hydrogen) measures the concentration of free hydrogen ions in a solution. The pH scale ranges from 0 (the most acidic) to 14 (the most basic), with 7 as the neutral mid-point. Most tap water and a number of spring and natural mineral waters have a pH around 7. Human blood has a pH of approximately 7.4 ± 0.05. It is essential for our bodies to maintain our blood pH within a tight range. Even a small fluctuation of as little as .05 in our blood pH can have severe health risks. However, the pH of the organs throughout the rest of the body can vary widely. In our stomach, the pH is acidic and varies from 1.5 to 3.5 during food digestion, while the pH of pancreatic juice is alkaline from 7.5–8.0.
The cell and tissues
Ian Peate, Helen Dutton in Acute Nursing Care, 2014
All physiological processes in cells are dependent on the correct pH. The pH is a measure of the hydrogen ion (H+) concentration or acidity/alkalinity of the environment and is represented by a number between 0 and 14 where 0 is the most acidic, 14 is the most alkaline and 7 is neutral. The normal pH of blood, for example, is between 7.35 and 7.45. The pH of the blood and therefore the pH of the body is regulated by the lungs and kidneys. This balance is represented by the equation Alteration of this balance leads to malfunction of cells. If the CO2 increases in the body because of poor respiration then the equation will be driven to the left, increasing the amount of H+ ions and therefore an increase in acidity and vice versa. If the kidneys are not able to function properly then removal of bicarbonate ion will decrease and there will be an increase in alkalinity. The overall process is much more complex than this but these examples are given as an example of the control of the cellular environment.
Gastrointestinal Function and Toxicology in Canines
Shayne C. Gad in Toxicology of the Gastrointestinal Tract, 2018
The gastric secretion of both hydrochloric acid and pepsinogen can be negatively modulated by the presence of excess acid. When the pH of gastric contents falls below that of 3.0, the gastrin mechanism for the stimulation of gastric secretion becomes nonfunctional, because the presence of hydrochloric acid seems to generate an inhibitory neural signal ceasing gastric secretion and directly blocking the secretion of gastrin by G cells. This acid-mediated feedback inhibition protects the stomach from the presence of excess acidity or too much pepsin, which could consequently damage the gastric mucosa. Similarly, this control mechanism also ensures that the pH of stomach contents lies within a range supportive of optimal enzymatic function. The optimal pH of stomach contents is considered to be approximately 3.0.
Appraisal of heavy metal toxicity in surface water with human health risk by a novel approach: a study on an urban river in vicinity to industrial areas of Bangladesh
Published in Toxin Reviews, 2021
Ram Proshad, Saiful Islam, Tanmoy Roy Tusher, Dan Zhang, Sujan Khadka, Jianing Gao, Satyajit Kundu
The physicochemical parameters along with the heavy metal concentrations in the surface water of the Rupsa river is presented in Table 1. The values of all the studied water quality parameters including pH, EC, and heavy metal (Cr, Ni, Cu, As, Cd and Pb) concentrations were found to be higher during the winter season as compared to the values obtained during the summer season. The mean pH was observed as 7.97 ± 0.052 and 8.07 ± 0.053 during the summer and the winter season, respectively, while the pH values were ranged from 7.53 to 8.76 during the summer and from 7.62 to 8.87 during the winter season (Table 1). The pH value represents the acidity or alkalinity of the water (Ravikumar ET AL. 2013). A pH value ranged between 6 and 8.5 indicates a productive water body (Garg ET AL. 2010), whereas the water with a low pH value is considered to be corrosive and can adversely affect the skin and eyes (Li ET AL. 2017). The observed pH values in this study indicated that the river water is productive and suitable for human consumption. Islam ET AL. (2018a) observed the mean water pH of Rupsa river as 8.5, ranged from 8.1 to 9.0 during a hydrological year 2016–2017, which was slightly higher than the mean pH value of 8.2 calculated for the whole hydrological year considered in this study regardless of the seasonal variations. Ali ET AL. (2016) studied the water quality of Karnaphuli river, one of the major coastal rivers in Bangladesh, and also found similar result like present study.
Assessment of trace element toxicity in surface water of a fish breeding river in Bangladesh: a novel approach for ecological and health risk evaluation
Published in Toxin Reviews, 2022
Md. Refat Jahan Rakib, Yeasmin Nahar Jolly, Bilkis Ara Begum, Tasrina Rabia Choudhury, Konika Jannat Fatema, Md. Saiful Islam, Mir Mohammad Ali, Abubakr M. Idris
Mean values of physical–chemical parameters of surface water samples from Halda River, Bangladesh are shown in Table 1. The pH of the aquatic systems is an important indicator of the water quality and the extent pollution in the watershed areas. It is the indicator of acidic or alkaline condition of water status. The standard for any purpose in-terms of pH is 6.5–8.5, in that respect; the mean value of pH in this study is 6.02 which indicates slightly acidic water. The pH value represents the acidity or alkalinity of the water (Ravikumar et al. 2013). A pH value ranged between 6 and 8.5 indicates a productive water body (Garg et al.2010), whereas the water with a low pH value is considered to be corrosive and can adversely affect the skin and eyes (Li et al.2017). APHA (2012) stated that industrial or municipal waste materials played a significant role in increasing or decreasing pH of the adjacent water body. Moreover, activities like bathing, washing, and latrines along water bodies related to fluctuations of water pH (Islam et al.2018a). Biochemical and chemical reactions are influenced by the pH (Manjare et al. 2010). Ali et al. (2016) studied the water quality of Karnaphuli River, one of the major coastal rivers in Bangladesh, and also found similar result of this study.
The relationship between the Hammett acidity and the decomposition of cefotaxime sodium in the solid state
Published in Drug Development and Industrial Pharmacy, 2020
Bashar M. Altaani, Khouloud A. Alkhamis, Shaima’a Abu Baker, Razan Haddad
In dilute solutions, the acidity is described by the regular pH scale. The use of this scale in highly concentrated solutions is not valid. Hammett proposed an acidity function that can be used in highly concentrated solutions. This function is based on the use of indicator molecules. The Hammett function [19–20] for acidic indicator is shown below: H is the proton activity, f is the indicator activity coefficient and A– and HA are the deprotonated and protonated indicator species respectively. The Hammett acidity function is dependent on the proton activity of the system and on the medium polarity which is expressed in the aforementioned equation by the ratio of the activity coefficients of the ionized to the unionized species of the probe [6]. The application of the Hammett acidity function was extended to solid systems [5,10,13]. Indicators were used to evaluate solid-state acidity using diffuse reflectance spectroscopy. In this method, the ionization of an indicator in solutions is measured using UV-VIS spectroscopy. The data are then used to construct a calibration curve. The same indicator is then added to solid samples and the ionization is measured using diffuse reflectance spectroscopy. The solid-state acidity is then determined from the calibration curves that were previously constructed.
Related Knowledge Centers
- Acid
- Alkali
- Chemistry
- Hydronium
- Purified Water
- Hydrogen
- Ion
- Thermodynamic Activity
- Equilibrium Chemistry
- Acid Strength