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Une molécule est une combinaison de deux atomes ou plus liés entre eux par des forces attractives appelées liaisons chimiques ; selon le contexte, l'expression peut inclure ou non les ions répondant à cette exigence. En physique quantique, en chimie organique et en biochimie, la différence entre molécules et ions est généralement ignorée, et le terme  molécule  est couramment utilisé pour désigner les ions polyatomiques. Les atomes sont les constituants essentiels d'un élément. Ils sont constitués d'un noyau et des électrons qui l'entourent.

Une molécule est une combinaison de deux atomes ou plus liés entre eux par des forces attractives appelées liaisons chimiques ; selon le contexte, l'expression peut inclure ou non les ions répondant à cette exigence. En physique quantique, en chimie organique et en biochimie, la différence entre molécules et ions est généralement ignorée, et le terme  molécule  est couramment utilisé pour désigner les ions polyatomiques. Les atomes sont les constituants essentiels d'un élément. Ils sont constitués d'un noyau et des électrons qui l'entourent.

A molecule is a combination of two or more atoms bound together by attractive forces known as chemical bonds; depending on the context, the phrase may or may not include ions that meet this requirement. In quantum physics, organic chemistry, and biochemistry, the difference between molecules and ions is typically ignored, and the term molecule is commonly used to refer to polyatomic ions. Atoms are the essential constituents of an element. They are made up of a nucleus and surrounding electrons. Valence electrons occur when an atom's electron shell is inadequate.

A polymer is any of a family of natural or synthetic compounds made up of larger molecules known as macromolecules, which are multiples of smaller chemical units called monomers. Many components found in living creatures are polymers, such as proteins, cellulose, and nucleic acids. Furthermore, they are the building blocks for minerals like diamond, quartz, and feldspar, as well as man-made materials like concrete, glass, paper, plastics, and rubbers. The word polymer refers to an unspecified number of monomer units.

An analytical instrument called a UV-vis spectrophotometer measures how much ultraviolet (UV) and visible light a sample absorbs. In chemistry, biochemistry, and other sciences, it is a widely used method for locating and measuring compounds in a variety of materials. 

Preparative chromatography is the process of isolating material from a sample using HPLC, usually in large amounts, by collecting separated peak fractions as they emerge from the detector. The basic objective of an analytical-scale separation is to provide a chromatogram with crisp, well-resolved, symmetrical peaks that provide the necessary analytical information.

Reversed-phase chromatography (RPC) is a liquid chromatography technology that separates molecules using hydrophobic interactions between solute molecules in the mobile phase and ligands linked to the stationary phase. 

The World Health Organization (WHO) is a United Nations body focused on global health and safety. The Organization brings together states, partners, and individuals to promote health, keep the world secure, and help the vulnerable. As a result, anyone, anywhere can achieve optimal health.

An official publication, first published by the American Pharmaceutical Association and now yearly by the United States Pharmacopeial Convention, that contains the composition, description, method of manufacture, and dose of medications. The book includes two independent official compendia: the USP and the NF.