Microaerophilic biodegradation of tallow-based anionic detergents in river water

Nine anionic detergents from five general classes (alcohol sulfates, ether alcohol sulfates, sulfated alkanolamides, α-sulfo esters and alkylbenzenesul-fonates) were rapidly screened for biodegradability under aerobic and microaerophilic conditions in river water at 25 and 35 C. In decreasing order, the ease of biodegradation under microaerophilic conditions at 35 C was as follows: alcohol sulfates, sulfated alkanolamides, α-sulfo fatty acid esters and ether alcohol sulfates. Linear alkylbenzenesulfonate did not degrade. Presented at the AOCS Meeting, New Orleans, April 1970.     

Soap-based detergent formulations: XV. Amino esters of α-sulfo fatty acids

Amphoteric surfactants were prepared either by direct esterification of α-sulfo fatty acids with various alkanolamines or by rearrangement of the corresponding alkanolamides of the α-sulfo fatty acids to the amino esters with the aid of aqueous hydrochloric acid. The α-sulfo fatty acid monoesters of diethanolamine could be prepared only via the rearrangement method. The amino esters in the C₁₆−C₁₈ range possessed limited water solubility whereas α-sulfolaurate esters were soluble at room temperature. The amino esters were found to be stable to acid hydrolysis; however, they were generally not stable to alkali, by which they were either hydrolyzed or rearranged to the corresponding amide. Only the esters of isopropanolamine and diglycolamine were stable to alkali. Surface active properties of the esters were determined. The lime soap dispersant requirements of the compounds were slightly poorer than those of the corresponding amides. The compounds were good cotton detergents by themselves as well as in combination with soap and a silicate builder. The overall surface active properties of the amino esters were greatly inferior to those of the sulfobetaines previously reported. This indicates that an effective amphoteric lime soap dispersant should have its anionic group located at the very end of the molecule and the cationic group somewhat farther away, instead of the reverse. Presented at the AOCS Meeting, Philadelphia, September 1974.     

The effect of tallow-based detergents on anaerobic digestion

Eight anionic detergents from three general classes (alcohol sulfates,a-sulfo fatty acid esters and alkylbenzenesulfonates were tested for biodegradability under anaerobic conditions of sludge digestion. The alcohol sulfates were found to be readily and completely degraded. Thea-sulfo fatty acid esters did not degrade but had no adverse effect on bacteriological digestion while the alkylbenzenesulfonates used for control purposes did not degrade and disrupted the normal digestion process. Preliminary lysimeter studies showed that sodium isopropyla-sulfostearate is completely degraded, linear alkylbenzenesulfonate 83%, and ABS 35%. Presented at the AOCS meeting, Chicago, 1964. E. Utiliz. Res. Devel. Div., ARS, USDA.     

Summary of the technology for the manufacture of higher alpha-sulfo fatty acid esters

Interest in α-sulfonated higher molecular weight (up to C₂₀) fatty esters has increased in recent years in the surfactant industry due to the advent of economical sulfonation processes and methyl esters of fatty acids. In this paper, the authors present a review of the chemistry of the sulfonation of fatty esters and the two-step mechanism leading to α-sulfonation. Laboratory and pilot plant scale preparation of long chain fatty acid α-sulfoesters with vaporized SO₃ without the use of solvents are also summarized. Work on the falling film equipment with hydrogenated methyl tallowate with vaporized SO₃ is described along with procedures for neutralization and bleaching. Analytical methods for defining the α-sulfonates are discussed. A larger scale unit to continuously manufacture α-sulfo fatty esters from long chain fatty acid is described. A review of the commercially available continuous processes for sulfonation of the fatty acid esters with vaporized sulfur-trioxide have also been included. The properties of the salts of α-sulfo fatty esters including the hydrolytic stability, aqueous solubility, lime soap dispersing ability, and biological properties have been tabulated. Uses of these surfactant range α-sulfo esters are included in this discussion. Presented at the AOCS Meeting, New Orleans, April 1976.     

Analysis of the dark-colored impurities in sulfonated fatty acid methyl ester

A fractionally distilled C₁₄−C₁₆ fatty acid methyl ester, derived from palm oil, was sulfonated with gaseous SO₃ in a falling film reactor to form an α-sulfo fatty acid methyl ester (α-SF; unbleached and unneutralized form). The included dark-colored impurities were then separated from α-SF as a diethyl ether-insoluble matter. After purification by thin-layer chromatography, the colored species were analyzed by ion-exchange chromatography, gel-permeation chromatography, and nuclear magnetic resonance spectrometry. These data suggested that the colored species were polysulfonated compounds with conjugated double bonds. Minor components in the raw fatty acid methyl ester, found by gas chromatography/mass spectrometry, were spiked into the purified methyl palmitate and then sulfonated. The unsaturated methyl ester and hydroxy ester showed the worst color results. The methyl oleate and methyl 12-hydroxystearate were then sulfonated and analyzed. Deep black products were obtained, which showed the same properties as the colored species in α-SF. It was concluded that low levels of unsaturated fatty acid methyl esters and hydroxy esters in the fatty acid methyl ester are the main causes of the coloring.     

Alpha sulfo fatty esters in biologically soft detergent formulations

Salts of α-sulfo tallow and coconut esters were subjected to river die-away, activated sludge and Warburg tests, and results show these derivatives to be biologically soft detergents with disappearance curves approximating those of the fatty alcohol sulfates. Selection of the proper fatty acid starting material, alcohol of esterification, and alkali for neutralization provides for a high degree of flexibility in tailor-making biologically soft surface active agents for a wide range of applications. Selected compounds have been found which exhibit remarkable foaming, lime soap dispersing, fabric and hard surface detergency, wetting and related surface-active properties. These properties allow the formulation of a variety of synthetic and soap-synthetic combinations. Primary emphasis is given to the presentation of data on surfactant formulation application studies. Salts of short chain alkyl esters of α-sulfo tallow acid are ideally suited for “combo” soap bar and built heavy-duty detergent applications. Salts of short chain alkyl esters of selected coconut fatty acids are uniquely suitable for light duty liquids, cosmetic and related surfactant applications. An improved process for the manufacture of these sulfo esters has been developed which produces high yield, high purity and light colored products, and which should provide for their acceptance on a large scale in the detergent field. Presented at the 37th Annual AOCS Meeting, Minneapolis, Minn. Oct. 1, 1963.     

α-Sulfonated fatty acid esters: I. Structural effects of sodium α-sulfonated fatty acid higher alcohol esters on surface-active properties and emulsification ability

The surface-active properties and emulsification ability of sodium α-sulfonated fatty acid esters, C_mH_2m+1CH-(SO₃Na)COOC_nH_2n+1, were studied as a function of the hydrophobic alkyl chainlength in the fatty acid (m=8−16) and the alcohol (n=8−18). As a result, it was discovered that sodium α-sulfonated fatty acid esters have a structural effect on the Krafft point different from that of amphiphiles with short alkyl chains. Moreover, some of the α-sulfonated fatty acid esters have quite low interfacial tensions, as well as non-foaming properties, which depend upon the total (m+n) number of carbon atoms in the alkyl chains.     

Benzyl,cyclohexyl, and phenyl esters ofalpha-sulfo fatty acids

Sodium salts of benzyl, cyclohexyl, and phenyl esters of α-sulfopelargonic, α-sulfopalmitic, and α-sulfostearic acids were prepared by reaction of the α-sulfo acid with excess of the alcohol or phenol, in the presence of methylene chloride, carbon tetrachloride, benzene, or toluene. Synthesis from the acid chloride of the α-sulfo acid gave lower yields of a less pure product. Melting point, surface and interfacial tension, critical micelle concentration, rate of hydrolysis and wetting, foaming and detergent properties were measured. The ring esters have properties similar to the corresponding propyl, butyl, or amyl esters. Presented at the AOCS Meeting, New Orleans, May 1967. E. Util. Res. Dev. Div., ARS, USDA.     

α-tocopherol oxidation mediated by superoxide anion (O 2 − ) I. Reactions in aprotic and protic conditions

The reaction of α-tocopherol (α-T) with superoxide anion (O ₂ ⁻ ) in both dry acetonitrile and in aqueous acetonitrile solution is described. The O ₂ ⁻ was generated by the electrochemical reduction of molecular oxygen in acetonitrile, using tetrabutylammonium bromide as an electrolyte. α-T was reacted with O ₂ ⁻ either in dry acetonitrile or in a 10% aqueous acetonitrile solution. In dry acetonitrile, α-T was oxidized to a very unstable primary intermediate, which was further oxidized to a secondary, more stable intermediate. The formation of the secondary intermediate depended upon the presence of molecular oxygen. This intermediate readily converted into two compounds in equimolar amounts (designated A and B). The primary, very unstable intermediate was readily reduced again to α-T by treatment with LiAlH₄ or ascorbic acid. However, the secondary intermediate or the stable oxidation products could not be reduced to α-T. In the 10% aqueous acetonitrile, α-T was oxidized to α-tocopheryl quinone, α-tocopherol dimer and α-tocopherol dihydroxy dimer, and an unknown compound. In the aqueous medium, no intermediates were formed by the action of O ₂ ⁻ . The results of this study indicate that the reaction of α-T with O ₂ ⁻ under aprotic conditions is different from that observed under protic conditions.     

Hexitol and sucrose esters of α-sulfo fatty acids

Use of the α-sulfo acid, the acid chloride and the methyl ester was explored in the preparation of mannitol, sorbitol and sucrose esters of α-sulfopalmitic and α-sulfostearic acids. The products were difficult to purify because of solubilization of reactants. The α-sulfo esters are more soluble and more resistant to hydrolysis than hexitol and sucrose palmitates and stearates. Presented at the AOCS Meeting, New York, October 1968. ARS, USDA.     

Chemical structure of long-chain esters from “sansa” olive oil

The major objective of this study was to determine the chemical structure of long-chain esters present in lower-grade olive oil. The classes of esters composing the hexanediethyl ether (99∶1) extract of the wax fraction from a pomace olive oil were: (i) esters of oleic acid with C₁−C₆ alcohols, (ii) esters of oleic acid with long-chain aliphatic alcohols in the range C₂₂−C₂₈ and (iii) benzyl alcohol esters of the very long-chain saturated fatty acids C₂₆ and C₂₈. The analysis and the structure assignments were carried out by gas chromatography coupled with mass spectrometry and by comparison with synthetic authentic model compounds. This work provided precise data on the chemical nature of the wax esters present in olive oil and should represent a means to detect adulteration of higher-grade olive oil with less expensive pomace olive oil and seed oils.     

Glycerylbisether sulfates. II: Performance properties

Traditional structure vs. performance relationships have been thoroughly investigated for alcohol ether sulfates (AES) wherein hydrophobe chainlength and degree of ethoxylation served as variables for structure variance. Therefore, a series of molecules, 1,3-bis-(alkylethylenoxy)-propane-2-yl sodium sulfates or glycerylbisether sulfates (GBES), analogous to AES but with a centrally located hydrophile structure, was synthesized and evaluated for its cloth detergency, foaming and wetting properties. Performance test results are presented as response surfaces in the two variables mentioned in addition to comparisons to common surfactants. The centrally located hydrophile structures exhibited varying surfactant and performance properties, with increasing detergency performance shown by higher-molecular weight GBES molecules: Optimum foaming and wetting performance was produced by a range of structures roughly given by C_nEO_n−6 for n=6–8.     

Kinetic Study of the Prooxidant Effect of α-Tocopherol. Hydrogen Abstraction from Lipids by α-Tocopheroxyl Radical

A kinetic study of the prooxidant effect of α-tocopherol was performed. The rates of allylic hydrogen abstraction from various unsaturated fatty acid esters (ethyl stearate 1, ethyl oleate 2, ethyl linoleate 3, ethyl linolenate 4, and ethyl arachidonate 5) by α-tocopheroxyl radical in toluene were determined, using a double-mixing stopped-flow spectrophotometer. The second-order rate constants (k _p) obtained are <1 × 10⁻² M⁻¹ s⁻¹ for 1, 1.90 × 10⁻² M⁻¹ s⁻¹ for 2, 8.33 × 10⁻² M⁻¹ s⁻¹ for 3, 1.92 × 10⁻¹ M⁻¹ s⁻¹ for 4, and 2.43 × 10⁻¹ M⁻¹ s⁻¹ for 5 at 25.0 °C. Fatty acid esters 3, 4, and 5 contain two, four, and six –CH₂– hydrogen atoms activated by two π-electron systems (–C=C–CH₂–C=C–). On the other hand, fatty acid ester 2 has four –CH₂– hydrogen atoms activated by a single π-electron system (–CH₂–C=C–CH₂–). Thus, the rate constants, k _abstr/H, given on an available hydrogen basis are k _p/4 = 4.75 × 10⁻³ M⁻¹ s⁻¹ for 2, k _p/2 = 4.16 × 10⁻² M⁻¹ s⁻¹ for 3, k _p/4 = 4.79 × 10⁻² M⁻¹ s⁻¹ for 4, and k _p/6 = 4.05 × 10⁻² M⁻¹ s⁻¹ for 5. The k _abstr/H values obtained for 3, 4, and 5 are similar to each other, and are by about one order of magnitude higher than that for 2. From these results, it is suggested that the prooxidant effect of α-tocopherol in edible oils, fats, and low-density lipoproteins may be induced by the above hydrogen abstraction reaction.     

Biodegradation of sodium alkyl poly(oxyalkylene)sulfates

The biodegradability of sodium alkylpoly(oxyalkylene)sulfates was studied under aerobic conditions by oxygen consumption, total organic corbon (TOC) and methylene blue active substance (MBAS) measurements. MBAS of linear alkylpoly(oxyalkylene)sulfates with propylene oxide (APS) or ethylene oxide (AES) disappeared within 5 days, whereas AES with branched alkyl chains were degraded less than linear AES. APS with propylene oxide from 1 to 3 mol showed BOD/ThOD values of more than 40% after 6 days. Therefore, these surfactants are considered to be readily biodegradable. In comparison to the biodegradability of APS and AES, the existence of propylene oxide groups resulted in a slight decreasing in oxygen consumption and TOC removal. Linear APS with PO of 1~3 mol were degraded according to Swisher's distance principle up to a C₁₆ alkyl chain length. That is, increasing distance principle up to a C₁₆ alkyl chain length. That is, increasing distance between sulfate and chain end increased the rate of biodegradation of these surfactants. Furthermore, from the biodegradation test of³⁵S-C₁₂E₃S, it is suggested that the initial step of biodegradation is attack on the terminal methyl group.     

α-tocopherol oxidation mediated by superoxide anion (O 2 − ). II. Identification of the stable α-tocopherol oxidation products

The present paper describes the identification of two stable end products of α-tocopherol oxidation that were previously detected among the products of the reaction of α-tocopherol with superoxide anion (O ₂ ⁻ ) under aprotic conditions. One compound, previously designated compound A, was identified astrans-7-hydroxy-trans-8,8a-epoxy-α-tocopherone, and the other, designated compound B, was identified ascis-7-hydroxy-cis-8,8a-epoxy-α-tocopherone. It was also observed that under protic conditions (10% water in acetonitrile) the reaction of α-tocopherol with O ₂ ⁻ did not produce compounds A and B, but rather α-tocopheryl quinone, α-tocopherol dimer, α-tocopherol dihydroxy dimer, and the previously designated compound C. Compound C was identified in the present study as α-tocopheryl-quinone-2,3-epoxide.     

Kinetics of the formation of symmetrical wax esters from the corresponding alcohols with the use of hydrobromic acid and hydrogen peroxide

The primary aliphatic alcohols n-octanol, n-decanol, and n-dodecanol have been converted to their corresponding symmetrical esters by using HBr and H₂O₂ in the absence of a solvent. The reaction was carried out at 30, 40, and 50°C and at mole ratios of alcohol to HBr of 1∶0.1, 1∶0.2, 1∶0.3, and 1∶0.5. The rate of the reaction was found to increase with increase in the reaction temperature and concentration of HBr. The maximal conversion of n-octanol was 72% at 40°C and a mole ratio of n-octanol to HBr of 1∶0.5. The kinetics of the reaction have been established, and the reaction was found to be first-order with respect to alcohol and bromine concentration in the organic phase, and second-order with respect to both. The second-order rate constants for n-octanol, n-decanol, and n-dodecanol are 27.08, 32.58, and 37.42 mL mol⁻¹ min⁻¹, respectively, at 40°C. The activation energy for the esterification reaction of n-octanol was found to be 16.32 kcal mol⁻¹.     

Properties of aqueous solutions of several salts of α,ω-alkanediol disulfates

Several salts of α,ω-sulfates, MO₃SO(CH₂)_n OSO₃M(n=12, 14, 16, 18, and M=Li, Na, and K) were prepared from the corresponding α,ω-alkane diols. The Krafft points of these α,ω-sulfates with common counterion as estimated by electroconductivity measurements increased with the increase of the hydrocarbon chain length, and the effect of the counterions on the Krafft points of the α,ω-sulfates with the same hydrocarbon chain length was in the order : Li<Na<K. Solutions of the α,ω-sulfates, except disodium dodecanediol disulfate, showed two break points corresponding to the first and second critical micelle concentration in each plot of the electroconductivity as a function of the concentration. The existence of the second break point suggested that another aggregation of rearrangement of the existing aggregates occurs in α,ω-sulfate solutions in addition to the usual micelle formation. The first and second break points of α,ω-sulfates with sodium counterion decreased logarithmically with increasing total number of methylene groups. The relationships were given as follows: log(first break point)=−0.138Nc−0.095; log(second break point)=−0.104Nc−0.251. The effect of the counterions upon the break points of α,ω-sulfates with the same hydrocarbon chain length was in accordance with their positions in the lyotropic series.     

Synthesis of deuterium labeled cholesterol and steroids and their use for metabolic studies

A simple method is described for the preparation of [6,7,7⁻²H₃] sterols and steroids. The synthesis starts with a Δ⁵-sterol or steroid and involves preparation of the 6-oxo-3α,5α-cyclosteroid, base exchange in the presence of deuterium oxide to introduce two deuteriums at the C-7 position and sodium borodeuteride reduction of the 6-oxo group to introduce the third deuterium atom at C-6. Rearrangement of the [6,7,7⁻²H₃]6α-hydroxy-3α,5α-cyclosteroid then gives the desired [6,7,7^-2H₃]-Δ⁵ sterol or steroid. [6,7,7⁻²H₃]Cholesterol, [6,7,7⁻²H₃]pregnenolone and [6,7,7⁻²H₃]3β-hydroxyandrost-5-en-17-one were synthesized in this fashion and [6,7,7⁻²H₃]progesterone was prepared from the [6,7,7⁻²H₃]pregnenolone. Three examples of the use of these deuchromatography-mass spectrometry. The chrysophyte alga,Ochromonas malhamensis, was shown to be capable of introducing an extra methyl or ethyl group at C-24 of the side chain of [6,7,7⁻²H₃]cholesterol to yield brassicasterol and poriferasterol, respectively. The ovary of the echinoderm,Asterias rubens, was demonstrated to metabolize [6,7,7⁻²H₃]progesterone to yield mainly the 5α-isomers of pregnane-3,20-dione and 3β-hydroxypregnan-20-one. However, the 5β-isomers of these compounds were also detected as minor products for the first time as progesterone metabolites in this animal. Isolated oocytes of the frog,Xenopus laevis, produced a number of metabolites of [6,7,7⁻²H₃]progesterone. In this report, two of them were shown to be 17α-hydroxy-pregn-4-en-3,20-dione and 20α-hydroxypregn-4-en-3-one. Presented at the “Sterol Symposium” of the American Oil Chemists' Annual International Conference, New Orleans, LA, May 1981.     

Soap-based detergent formulations: IX. α-sulfo fatty alkanolamides as lime soap dispersing agents

α-Sulfo fatty alkanolamides were prepared by sodium methylate catalyzed reactions of methyl α-sulfo fatty esters with alkanolamines, such as ethanolamine, N-methyl-2-hydroxyethylamine, diethanolamine, 3-hydroxypropylamine, 2-hydroxypropylamine, and diglycolamine. Pure compounds, such as α-sulfo palmitamides and stearamides, as well as the α-sulfo tallow amides, were prepared and evaluated as surface-active agents. The α-sulfo fatty alkanolamides were found to have excellent stability to alkali. Their stability to acid ranged from excellent in the case of α-sulfo diglycolamides to poor in the case of α-sulfo diethanolamides. Poor stability to acid was related to ease of conversion to ester-amines. Washing tests on standard soil cloths showed that the compounds were good detergents by themselves and were also effective in combination with soap and silicates. Their lime soap dispersant requirements ranged from 7–10. Presented at the AOCS Meeting, September 1973, Chicago. ARS, USDA.     

Kinetic study of the reaction between tocopheroxyl radical and unsaturated fatty acid esters in benzene

A kinetic study of the reaction between a tocopheroxyl radical and unsaturated fatty acid esters has been undertaken. The rates of allylic hydrogen abstraction from various unsaturated fatty acid esters (ethyl oleate2, ethyl linoleate3, ethyl linolenate4, and ethyl arachidonate5) by the tocopheroxyl radical (5,7-diisopropyltocopheroxyl6) in benzene have been determined spectrophotometrically. The second-order rate constants, k₃, obtained are 1.04×10⁻⁵ M⁻¹s⁻¹ for2, 1.82×10⁻² M⁻¹s⁻¹ for3, 3.84×10⁻² M⁻¹s⁻¹ for4, and 4.83×10⁻² M⁻¹s⁻¹ for5 at 25.0°C. Thus, the rate constants, k_abstr/H, given on an available hydrogen basis are k₃/4=2.60×10⁻⁶ M⁻¹s⁻¹ for2, k₃/2=9.10×10⁻³ M⁻¹s⁻¹ for3, k₃/4=9.60×10⁻³ M⁻¹s⁻¹ for4, and k₃/6=8.05×10⁻³ M⁻¹s⁻¹ for5. The k_abstr/H values obtained for the polyunsaturated fatty acid esters3,4, and5 containing H-atoms activated by two π-electron systems are similar to each other, and are about three orders of magnitude higher than that for the ethyl oleate2 containing H-atoms activated by a single π-system. From these results, it is suggested that the prooxidant effect of α-tocopherol in edible oils and fats may be induced by the above hydrogen abstraction reaction.