Buch, Kurt published the artcileSpectrophotometric investigation of color indicators, HPLC of Formula: 596-01-0, the publication is Soc. Sci. Fennica Commentationen. Phys. Math. (1926), 2(Nos. 19-30), 20 pp., database is CAplus.
The spectrophotometer offers certain advantages for determining pH values, particularly in natural waters such as sea water. If the relationship between light absorption and hydrogen-ion concentration is known, no comparison solution is necessary. In this paper the optical properties of α-naphtholphthalein, bromocresol purple, bromothymol blue and phenol red were studied near the neutral point. The light absorption of solutions of definite concentration for different wave lengths was determined both in alk. and in acid solution This is necessary to show the sort of light most suitable for the colorimetric determinations The indicators mixed with buffer solutions were then studied with the light of chosen wave length with respect to the dependence of the light absorption upon H-ion concentration In this way the ionization constants of the indicators were determined with considerable accuracy.
Soc. Sci. Fennica Commentationen. Phys. Math. published new progress about 596-01-0. 596-01-0 belongs to benzofurans, auxiliary class Benzofuran,Naphthalene,Alcohol,Ester, name is 3,3-Bis(4-hydroxynaphthalen-1-yl)isobenzofuran-1(3H)-one, and the molecular formula is C28H18O4, HPLC of Formula: 596-01-0.
Referemce:
https://en.wikipedia.org/wiki/Benzofuran,
Benzofuran | C8H6O – PubChem