Abstract
In order to establish the method of analysis of Bisphenol A (I) and impurities in it, the application of gas chromatographic technique has been studied.
Di- and tri-nuclear phenols were partially decomposed when C-22 firebrick, Chromosorb P and W (acid washed) and others were used as column support at high temperature. These phenols could be determined quantitatively without decomposition by using column containing 10 weight% up of Apiezon grease L (AL) as a stationary phase on Celite 545 (acid washed) below the decompositon temperature.
For the separation of di-nuclear phenols[(1), 2-(2-hydroxyphenyl)-2-(4-hydroxyphenyl)propane(II), and 4, 4'-hydroxyphenyl-2, 2, 4-trimethylchroman (III)], a mixed column (3mm×40cm) was used at 220°C. It contained 20 weight% of AL mixed with polycarbonate (10 to 15 weight% to AL) as a stationary phase on Celite 545. The flow rate of helium as the carrier gas was maintained 100 ml per minute. In the case of the trace analysis of impurities in. I, these phenols exclusive of I could be determined quantitatively using p-phenylphenol as an internal standard, after extraction with xylene at its boiling point.
Tri-nuclear phenols [2, 4-bis(α, α-dimethyl-4-hydroxybenzyl)phenol(IV)] in I could be determine quantitatively using 2, 6-bis(2'-hydroxy-3'-tert-butyl-5'-methylbenzy1)-4-methylphenol (Antioxidant-80) as an internal standard. The column (2.5mm×40cm) contained 10 weight% AL as a stationary phase on Celite 545, and its temperature was 300°C. The optimum flow rate of helium as the carrier gas was 30ml per minute.
Determination of IV was not disturbed by a presence of a large quantity of I.
