The wide use of the auxin, indoleacetic acid, in physiological and biochemical experiments has promoted interest in methods for its colorimetric estimation. MITCHELL and BRUNSTETTER (1) have proposed both the nitrite and the ferric chloride-sulphuric acid tests for the quantitative estimation of indoleacetic acid (IAA) in aqueous solutions, basing their suggested procedures upon a study of opti...

This research investigated the effect of three different acids (sulphuric acid, hydrochloric acid and nitric acid), on three different clay deposit samples, to recycle used lubricating oil. To achieve this objective, filtration of the used oil was carried out first to remove impurities like: sand, metal chip and other micro impurities using: Buncher funnel, filter papers and vacuum pump. The fi...

Experimental Reagents and chemicals m-Phenylenediamine (mPDA >99%) was purchased from Acros Organics, ethylenediamine (EDA, Sigma Ultra) was obtained from Sigma Aldrich. ortho-Phosphoric acid (85%, ACS certified) was purchased from Fisher Scientific. All the other chemicals were of analytical grade. Buffer solutions with different pH were prepared using chemicals (such as sulphuric acid, citric...