Color Developing Agent 1 (CD-1) is the first in the series of color developing agents used in developing
color films. It is the organic compound ''N'',''N''-diethyl-1,4-benzenediamine (DPD), which is usually in the form of the mono
hydrochloride salt.
In color development, after reducing a
silver
Silver is a chemical element with the Symbol (chemistry), symbol Ag (from the Latin ', derived from the Proto-Indo-European wikt:Reconstruction:Proto-Indo-European/h₂erǵ-, ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, whi ...
atom
Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Only the most common variety of hydrogen has no neutrons.
Every solid, liquid, gas, and ...
in a
silver halide
A silver halide (or silver salt) is one of the chemical compounds that can form between the element silver (Ag) and one of the halogens. In particular, bromine (Br), chlorine (Cl), iodine (I) and fluorine (F) may each combine with silver to prod ...
crystal
A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...
, the
oxidized
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a d ...
developing agent
combines with a color coupler to form a
color dye
A dye is a colored substance that chemically bonds to the substrate to which it is being applied. This distinguishes dyes from pigments which do not chemically bind to the material they color. Dye is generally applied in an aqueous solution and ...
molecule
A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioch ...
.
Arthur Thomas Palin
Arthur Thomas Palin (b. 16 October 1916 - 2006) was a British chemist and bacteriologist. As well as inventing the DPD method of detecting chlorine in water and working as an official advisor to the American Water Works Association (AWWA), Pali ...
, a Fellow of the
Royal Society of Chemistry
The Royal Society of Chemistry (RSC) is a learned society (professional association) in the United Kingdom with the goal of "advancing the chemistry, chemical sciences". It was formed in 1980 from the amalgamation of the Chemical Society, the Ro ...
, developed a widely-used color based method of
water testing
Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a ...
using DPD to indicate the
chlorine
Chlorine is a chemical element with the Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate betwee ...
content of treated water.
See Also
*
Color Developing Agent 2
Color Developing Agent 2 is the second in the series of color developing agents used in developing Color photography, color films. It is commonly known as CD-2 and is chemically known as 4-diethylamino-''o''-toluidine, 1,4-benzenediamine, N4,N4-d ...
*
Color Developing Agent 3
*
Color Developing Agent 4
The fourth in the series of color developing agents used in developing Color photography, color films, commonly known as CD-4, is chemically known as 4-(N-Ethyl-N-2-hydroxyethyl)-2-methylphenylenediamine sulfate. In color development, after reduci ...
References
{{organic-compound-stub
Photographic chemicals
Anilines