However, it seems that few people in the apparel industry understand that such a color change problem can be caused by nitrogen oxide gas. Some of them have even said, "we have never imagined that nitrogen oxide gas can actually cause such a problem."

In fact, by carrying out grease reagent test we can easily detect whether or not fiber has the quality of adsorbing nitrogen dioxide. We already have what we really need to solve the color change problem. However, we often hear a wrong explanation about the test. That is, "two important substances used for the test are sulfanilic acid and alphana-butylamine." Troubles are found here if such a wrong explanation of the test is accepted as if it is the truth. In a true story, "alpha(na)-butylamine" has not been used. It is alpha-butyl-ethylenediamine that has been used in the test, and it has been found significant especially in biochemistry as the substance that causes color reaction when an azo compound is generated by nitrogen dioxide.

Searching through the database called "World Textile or Textile Technology Digest" on the Internet, you will be able to find about 50 entries talking about the color change problem caused by nitrogen oxide gas. The problem is not new for Japanese researchers. Some significant research has been done for this problem. Since it was found that nitrogen monoxide, as an information transmitting substance, has a great deal to do with various physical phenomena, it has not been too far for them to find a more accurate way to measure this sort of chemical substance.

(T.T.)