What is Bromothymol Blue Reagent Grade?

Answer 1

Bromothymol blue is a dye that is used primarily an acid-base indicator (see http://en.wikipedia.org/wiki/Bromothymol_blue) in laboratory and industrial chemistry.

The designation "Reagent" indicates that a chemical substance conforms to a high standard of purity, which standard is set forth either by government or by a professional chemical society, such as the American Chemical Society (ACS). Without knowing which standard the "reagent" chemical adheres to, it is necessary to have what is called a "guaranteed analysis", which is usually printed on the bottle label. Otherwise the term "reagent" is unimportant, and the chemist should assume that the chemical is "reasonably pure for preparative purposes" which is the orignal meaning of "technical grade".


Working chemists in the United States will prefer to use chemicals designated "ACS" or "ACS Reagent" when performing research procedures that may be, or must be, reproduced in exacting detail by others. Use of such standardized chemicals makes the task of re-creating the original reaction conditions much easier. The designation "ACS" has effectively replaced the term "Reagent" in modern chemical production in the United States. ACS does NOT necessarily mean the purest available in commerce; it simply means very pure, and adhering to a standard. Purer grades than ACS include "CP", which is the purest obtainable by commercial procedures, Chromatography Grade, and others.