Related Experiment Video
Updated: Jul 6, 2026
09:24
Application and Methodology of the Non-destructive 19F Time-domain NMR Technique to Measure the Content in Fluorine-containing Drug Products
Published on: August 22, 2017
Fluoride content in table salt distributed in Mexico City, Mexico
Juan Carlos Hernández-Guerrero1, Javier de la Fuente-Hernández, Maria Dolores Jiménez-Farfán
1Laboratorio de Inmunología, DEPeI, Facultad de Odontología, Universidad Nacional Autónoma de México, Circuito Institutos s/n, Ciudad Universitaria, México D.F.C.P 04510, México. jcarlosh@servidor.unam.mx
Journal of Public Health Dentistry
|April 4, 2008
Summary
Table salt in Mexico City shows wide fluoride variations, with 92% not matching label claims. Public health authorities need stricter controls for safe fluoride levels in salt for consumption.
Area of Science:
- Food Science
- Public Health
- Analytical Chemistry
Background:
- Fluoride fortification in salt is a public health strategy to prevent dental caries.
- Ensuring accurate fluoride levels in salt is crucial for effective public health interventions.
Purpose of the Study:
- To determine fluoride concentrations in table salt brands available in Mexico City.
- To compare measured fluoride levels against Mexican and World Health Organization (WHO) regulations.
Main Methods:
- Analysis of 44 table salt brands randomly sampled from Mexico City.
- Triplicate analysis using an Orion 720 A potentiometer and ion-specific electrode in three laboratories.
Main Results:
- Fluoride concentrations ranged from 0 to 485 ppm, indicating significant variability.
- 92% of samples had fluoride levels inconsistent with their labels.
- Only 6.8% of analyzed salt samples met Mexican and WHO fluoride regulations.
Conclusions:
- Wide fluoride concentration discrepancies in table salt necessitate improved regulatory oversight.
- Mexican Public Health authorities should implement stricter guidelines for salt distribution and fluoride content control.
Related Concept Videos
02:42Ionic Crystal Structures
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
01:26Minerals
Minerals are essential nutrients that the human body needs in small amounts to work properly. They play a vital role in many bodily functions, such as building strong bones and transmitting nerve impulses. Some minerals are needed for hormone production or to maintain a normal heartbeat. Major minerals include calcium, phosphorus, potassium, sulfur, sodium, chlorine, and magnesium, while trace minerals include iron, manganese, copper, iodine, zinc, cobalt, fluoride, and selenium.
04:08Determining the pH of Salt Solutions
The pH of a salt solution is determined by its component anions and cations. Salts that contain pH-neutral anions and the hydronium ion-producing cations form a solution with a pH less than 7. For example, in ammonium nitrate (NH4NO3) solution, NO3− ions do not react with water whereas NH4+ ions produce the hydronium ions resulting in the acidic solution. In contrast, salts that contain pH-neutral cations and the hydroxide ion-producing anions form a solution with a pH greater than 7. For...
02:55Solubility of Ionic Compounds
Solubility is the measure of the maximum amount of solute that can be dissolved in a given quantity of solvent at a given temperature and pressure. Solubility is usually measured in molarity (M) or moles per liter (mol/L). A compound is termed soluble if it dissolves in water.
01:09Solubility Equilibria: Overview
When a substance such as sodium chloride is added to water, it dissolves, forming an aqueous solution. The extent of dissolution is called solubility. The process of dissolution can exist in equilibrium, just like other chemical processes. Solubility equilibria are also called precipitation equilibria because the process of solubility can be reversible. The reverse of the solubility process is called precipitation.
Solubility is important in biological and environmental processes. A notable...
Solubility is important in biological and environmental processes. A notable...
04:01Factors Affecting Solubility
Compared with pure water, the solubility of an ionic compound is less in aqueous solutions containing a common ion (one also produced by dissolution of the ionic compound). This is an example of a phenomenon known as the common ion effect, which is a consequence of the law of mass action that may be explained using Le Chȃtelier’s principle. Consider the dissolution of silver iodide: