Thin-layer and high-speed liquid chromatography of the derivatives of 1,4-phenylenediamine

Occupational eczema from N‐isopropyl‐N′‐phenylparaphenylenediamine (IPPD) and N‐dimethyl‐1,3 butyl‐N′‐phenylparaphenylenediamine (DMPPD) in tyres

“…Analysis. Colorimetry tests were ruled out (interference, extract discoloration) and gas chromatography (GC) chosen rather than thin-layer chromatography (TLC) (see Ivan & Ciutacu 1974, Uchytil 1974 Warner 1969 for the following reasons: a) GC makes for easier separation of the eluted compounds, especially when oils and phthalates are involved; b) because of its relatively high detection limit (using a catharometer), it is possible to make a thin-layer chro· matography of selected parts of the chromatogram (after trapping); c) it is easier to combine selective infrared spectrophotometry; the trapped quantity is also sufficient to obtain an ultra-violet spectrum. The procedure is as follows: the nitromethanic extract, after being dried at 50-60°C, is dissolved in acetone and injected into a 2 m X 0.6 cm chromatograph column filled with Chromosorb® with 7.5 % Apiezon L, set at 150 rising to 300°C (temperature increase 6°C/min), and then maintained at 300°C.…”