Five macroreticular, nonionic Amberlite XAD resins were evaluated for concentration and isolation of fulvic acid from aqueous solution. The capacity of each resin for fulvic acid was measured by both batch and column techniques. Elution efficiencies were determined by desorption with 0.1 N NaOH. Highest recoveries were obtained with the acrylic ester resins which proved to be most efficient for both adsorption and elution of fulvic acid. Compared to the acrylic ester resins, usefulness of the styrene divinylbenrene resins to remove fulvic acid Is limited because of slow diffusion-controlled adsorption and formation of charge-transfer complexes, which hinders elution.There is a growing interest on the part of researchers to determine the contribution by humic substances to biological, physical, and geochemical processes in natural water systems. These substances, which constitute a ubiquitous class of naturally occurring, polyelectrolytic organic compounds, are known to play a role in the food chain, to affect the aesthetic quality of water by imparting color, to act as complexing agents for inorganic ions, and to aid in the movement of less soluble organic compounds, such as pesticides, in the aqueous environment (1). In addition, it is known that humic substances are precursors for haloforms in waters treated by chlorination ( 2 ) . The further study of these substances requires that they be efficiently isolated and concentrated from natural water.In recent years, it has been found that high recoveries of organic compounds from water are possible with macroreticular Amberlite XAD resins (3). These resins are nonionic, macroporous copolymers which possess large surface areas. There has been much study of the use of XAD resins for isolation, concentration, and chromatographic separation of many chemically distinct classes of compounds ( 4 , s ) . Some work has also been done with more chemically complicated humic substances. XAD-1 and XAD-2 have been shown to be effective adsorbents for removal of humic substances from seawater (6, 7), and XAD-2 has been used to isolate these substances from river water (8). Use of these resins for concentration and isolation of humic substances from natural waters is an improvement over activated carbon, because they are easier to elute and are free from the risk of chemical alteration of the humics (6). In addition, XAD resins have greater adsorption capacities and are easier to elute than alumina, silica gel, nylon, and polyamide powder (6).This paper presents a comparison and evaluation of five XAD resins for isolation and concentration of fulvic acid from water. A second objective of this research is to obtain a better understanding of the adsorption process of these poorly defined, albeit omnipresent, environmental compounds. E X P E R I M E N T A L Resin. The five resins studied (Table I) differ in pore size, surface area, polymer composition, and polarity (9). Three of the resins XAD-1, XAD-2, and XAD-4, are styrene divinylbenzene copolymers, which are not easily wetted an...

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The viscosities and electrical conductivities of solutions of CuHPO4 in aqueous phosphoric acid and phosphoric acid‐glycerol‐ethylene glycol mixtures were measured with a view to investigating the anode layer formed when copper is electrolytically polished in these solutions. Dissolved copper was found to raise the viscosity considerably, the increase being greater in the mixtures with glycol and glycerol than in phosphoric acid alone. The copper concentration near the anode during electrolysis was measured, and current‐voltage relationships were studied using a rotating copper anode. The effective thickness of the anode layer was estimated to be about 10−3 cm.

Analytical chemistry begins when a chemist asks, "What's in it?" If the "it" is at all complicated, like a rock or part of an animal or plant, the analytical chemist must be ready to use a wide variety Yet another type of exchanger is inorganic in nature, based on the hydrous oxides of elements of the fourth,

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The ionization constants of methyl-, ethyl-and phenylmercuric hydroxides and of methylmercuric chloride and bromide have been measured by potentiometric titration. All are weak electrolytes. The solubility products of methyl-and phenylmercuric halides have been found, partly potentiometrically and partly by direct solubility measurements. A convenient way of titrating alkyl mercuric hydroxides is described, and evidence is given to show that a certain method for preparing solid methyl mercuric hydroxide actually leads to the oxide.(1) Most of this work is taken from the Ph.D. thesis of Thomas D.

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