Ether sulfates assay

The ether fractions of the first and second partitions were pooled, those of the next two were pooled, and this procedure was continued until the 12 fractions were in six groups. Each of the pooled ether fractions was dried overnight with anhydrous sodium sulfate. The ether solution was decanted and evaporated to dryness. The residue from each ether extract was dissolved in 5 ml. of water and an aliquot assayed with Little Marvel pea seedlings. 

Optical (Specific) Rotation Transfer an accurately weighed amount of sample, equivalent to about 100 mg of total tocoph-erols, into a separator, and dissolve it in 50 mL of ether. Add 20 mL of a 10% solution of potassium ferricyanide in a 1 125 sodium hydroxide solution, and shake for 3 min. Wash the ether solution with four 50-mL portions of water, discard the washings, and dry over anhydrous sodium sulfate. Evaporate the dried ether solution on a water bath under reduced pressure or in an atmosphere of nitrogen until about 7 or 8 mL remains, and then complete the evaporation, removing the last traces of ether without the application of heat. Immediately dissolve the residue in 5.0 mL of isooctane, and determine the optical rotation. Calculate the optical rotation [see Optical (Specific) Rotation, Appendix HB], using as c the concentration expressed as the number of grams of total tocopherols, as determined in the Assay (above), in 100 mL of the solution. 

Hygroscopic, dark red crystals. When exposed to air, may absorb about 12% water. The hydrated crystals are stable to air. Darkens at 210-220 . Not melted at 300 . [a] — 59 9" (dil aq soln). Absorption max (water) 278, 361. 550 nm (A12, 115. 204, 64). Odorless and tasteless. One gram dissolves in about 80 ml water. Aq solns are neutral, maximum stability in the pH range 4.5-5. Solns in this pH range can be autoclaved for 20 min at 120 . Soluble in ale. Insol In acetone, CHCl3, ether. Aq solns decomp in the presence of acacia, aldehydes, ascorbic acid, ferrous gluconate, ferrous sulfate, vanillin are stabilized hy the addn of ammonium sulfate. Talc has a tenacious affinity for vitamin B1t although this is not an incompatibility, it precludes the use of talc as a filter aid or lubricant for tablets, particularly in view of possible assay difficulties. 

Several surfactants of different types (nonionic, anionic, cationic, and zwitterionic) have been assayed, but most reported procedures use the anionic surfactant sodium dodecyl sulfate (SDS, CMC = 8.2xl0 moll-i at 25°C), which is readily available. Other common surfactants are the cationic cetyltrimethylammonium bromide (CTAB, CMC = 9 X 10 moll ), and the nonionic Brij-35 (polyoxyethylene (23) dodecyl ether, CMC = 1 X 10 moll ). Common solvents in RPLC (methanol, ethanol, propanol, acetonitrile, and tetrahydrofuran) are suitable modifiers. Other less polar solvents, such as butanol and pentanol, can... 

The enzyme w as originally isolated by treatment of a rat liver supernatant fraction to pH 5.2 and dialj sis followed by ammonium sulfate fractionation (Booth ei al, 1961). It was assayed with 3,4-dichloro-nitrobenzene (Type II) at pH 8.0. The enzyme was subsequently almost freed of A -alkyltransferase and 8-epoxidetransferase activities by incubating for 15 minutes at pH 5 (Bo,yland and William.s, 1965). Epoxides caused varying amounts of inhibition of tlie A -aryltransferase 1,2-epoxy-1,2,3,4-tetrahydronaphthalene, 50% 1,2-epoxyindaiie, 85%, and 2,3-epoxj propylphenyl ether, 20-25%. Benzyl chloride caused a 44% inhibition (Booth et al, 1901). The iiiliibitions were regarded as being noncompetitive. 

Penicidin. Atkinson, et al. (12) have reported on tenicidin, which is formed by a unidentified species of PeniciUium and has been prepared as the crystalline sulfate. It seems to be a basic substance, soluble in ethyl acetate and ether, and slowdy inactivated at pH 7.5. It reduces permanganate, is. stable at pH 2, and unstable at pH 8. It gives no color reaction with ferric chloride. Penicidin is active against E. typhosa. An anti-luminescent method is used as one of the assay procedures (12). Penicidin may be glio-toxin or a closely related substance. 

There are separate ISO standards for primary and secondary alkyl sulfates (i.e., for products made from primary or secondary alcohols). The ISO standard covering primary alkyl sulfates specifies neutral oil by extraction from ethanol/water solution, total combined alcohols by ether extraction after acid hydrolysis, pH of a 10% aqueous solution, water by titration if below 10% or by azeotropic distillation if above 5%, and chloride by titration (60). The standard covering secondary alkyl sulfates is similar, but combined alcohols are not determined. Assay is by determination of total solids after extraction of the neutral oil, corrected for the presence of other impurities (61). 

ISO standard 893 covers analysis of alkanesulfonates, specifying assay by gravimetry, alkane monosulfonates by titration or extraction (Sections 2(a) and 2(c), below), neutral oil by petroleum ether extraction of an isopropanol/water solution, pH of a 5% aqueous solution, water by Karl Fischer titration or azeotropic distillation, sulfate by titration with lead nitrate, sulfite by iodometric titration, and chloride by potentiometric titration (99). The value for neutral oil can be checked for losses due to evaporation by confirming that the weight of the sulfonates and other salts in the 2-propanol/water phase plus the water content and weight of neutral oil is equal to 100%. 

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