Determinations of Phenols in Aqueous Wastes from Coke Plants

Abstract

E. Add 10 ml. of 2.0% potassium ferricyanide solution to all portions and mix immediately. F. Immediately pour 100 ml. of the sample and the 0.2 p.p.m. standard into individual 100-ml. Nessler tubes.If the sample does not show more red color than the standard, consolidate the entire sample portion and put it in a 1-liter separatory funnel. Put the blank and the 0.04 p.p.m. standard in 1-liter separatory funnels. Extract these solutions serially with 15-, 10-, and 5-ml.portions of chloroform. Combine the extracts and make them up to 25 ml. with chloroform. Filter the extracts before volume adjustment if high precision or high sensitivity is required.G. Read the optical density of both the 0.04 p.p.m. standard and the sample at 460 µ against the blank extract.If the optical density of 5 cm. of liquid is over 1.0, base comparisons on readings made using 1-cm. tubes.H. Compute the phenol content on a proportional basis, as the reaction is linear.I. If at step D the sample is darker than the 0.20 standard, start comparisons immediately using the aqueous solutions. Read both the sample and the 1.0 p.p.m. standard against the aqueous blank at 510 µ and calculate the phenol content of the sample on a proportional basis.SUMMARY Investigation of the reaction between 4-aminoantipyrine and phenols for analytical purposes indicates the following factors to be significant:The reaction products may be concentrated by extraction with chloroform in the case of all phenols investigated. The red aqueous dyes are extracted with chloroform to yield orange or yellow solutions. Serial extractions may be so arranged that the extraction is substantially quantitative and a large concentration factor is obtained.The aqueous reaction mixture is unstable. When allowed to stand, the color produced by the reaction of phenol and 4-amino-antipyrine fades. Concurrently, the color due to the reagents increases.

Interference by Surface-Active Agents with the 4-Aminoantipyrine Determination of Hexachlorophene and Other Phenols

“…The generation of dye in both the presence and absence of additive was extremely rapid with maximum and stable absorbance values being attained in a matter of seconds following the addition of oxidant. The order in which reagents are mixed is an important determinant of the amount of dye which is formed (6,7,11). Thus, addition of potassium ferricyanide to solutions of LCAAP in the absence of phenol, rapidly and irreversibly oxidizes the 4-AAP.…”

“…A number of reports have appeared in the literature describing the application of the reaction to the quantitative estimation of phenols (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21). These include a number of extensive reviews of methodology (6,7,9,21).…”

Destruction of Phenols by Oxidation of Ozone

“…The phenolic content was determined with 4-aminoantipyrine reagent (2, 4,5,12,18). Ammonium hydroxide was used to adjust the pH of the distilled sample and ammonium persulfate was the oxidant.…”

Interference of oxidants in the determination of phenol by the 4-aminoantipyrine and ultraviolet ratio spectrophotometric methods

“…All solutions were stored in glass. The methyl orange, ammonium hydroxide (1 to 1), and phosphoric acid (1 to 9) were dispensed by 4-oz dropping bottles (Arthur H. Thomas Co. No. 2248-B,4) that gave drops of about 0.08 mL (the volumes of the drops are important for the UV ratio method).…”