A high-performance liq. chromatog. method was used for the anal. of nonionic surfactants (oleyl and dibromostearyl alcs. ethoxylated with 1-20 oxyethylene units). The method involved the use of a Lichrosorb SI-60 (10 $μ$) column (4.6 mm internal diam., 25 cm long) with a hexane-MeOH-Me2CHOH mixt. as the mobile phase at 50° with UV detection at 220 nm. No derivatization of the ethoxylates was required. An improved baseline was achieved by adding anthracene to the eluents. [on SciFinder(R)]

High-performance liq. chromatog. was used to sep. and identify oleate and 9,10-dibromostearate esters of polyethylene glycols having various d.p. A Lichrosorb SI-60 (10 $μ$m) column was used with gradient elution (using a mixt. of iso-PrOH, MeOH, and hexane at 50°) and UV detection at 220 nm for the best sepn. of ethoxylates having d.p. ≤20. No derivatization of the ethoxylates was required. An improved baseline was obtained by adding negligible amts. of anthracene to the eluent. [on SciFinder(R)]

The reaction of Na stearate [822-16-2] with epichlorohydrin [106-89-8] in the presence of phase-transfer catalysts (tetraalkylammonium halides) gave 90% glycerol monostearate [31566-31-1] with purity 97%. The effect of reactant ratio, catalyst type and concn., and temp. were studied. An efficient, economical process was developed, including recycle of solvent and excess epichlorohydrin and recovery of 80% catalyst. The monoglycerides so prepd. are not food grade, but com. monoglycerides can be prepd. [on SciFinder(R)]

Crystal size distribution and the yield of Ca oxalate crystals were detd. in solns. with an admixt. of 5 normal and 3 stone forming urines. A pos. correlation was found between the median size and no. of particles and the overall inhibitory potentials of the urines toward Ca oxalate pptn. in vitro as reflected by discriminating index (DI) [sic] measurements. Incubation of 2 samples of stone formers' (SF) urines with glutamic-oxalacetic-transaminase (GOT) caused a redn. of aspartic acid concn., an increase in glutamic acid concn. and a parallel decrease in the DI values. After 90 min of SF urine incubation with GOT the DI in three samples was improved and both the median size and no. of particles were reduced, by 28% and 45% resp. These results could indicate that GOT activity changes the inhibitory power of the SF urine by transforming aspartic acid into glutamic acid, having thus most probably a part in the inhibition of Ca oxalate stone formation. [on SciFinder(R)]

Solubilities were detd. at 11-50° in MeOH, EtOH, Me2CO, MeCN, and iso-PrOH and in some aq. mixts. of these solvents. The soly. data are represented by best-fit equations for each solvent. [on SciFinder(R)]

Surfactants prepd. by bromination of the double bonds of oleate groups of sorbitan monooleate (I), sorbitan trioleate (II), and polyoxyethylene derivs. of I and II were effective emulsifiers in the prepn. of oil-in-water emulsions. The HLB values of the brominated compds. were similar to those of starting compds. The use, formation, and the stability of emulsions were detd. [on SciFinder(R)]

Correlation between the degree of satn. of both emulsifiers and vegetable oils has been examd. for a variety of water-in-oil (w/O) emulsions. Emulsions prepd. with unsatd. emulsifiers and highly unsatd. vegetable oils (contg. mainly oleic and linoleic acids) were more stable than those prepd. with some unsatd. emulsifiers and vegetable oils consisting of less unsatd. fatty acids. Moreover, emulsions prepd. with satd. emulsifiers and fully satd. oils have shown better stability than similar emulsions prepd. with less satd. oils. Since rigidity of the emulsifier and emulsifier-oil interactions on the film are dominant factors in stabilization of w/o emulsions, it is suggested to stabilize water in unsatd. vegetable oil emulsions using specially designed polyglycerol esters of dimerized soybean oil to achieve both requirements. [on SciFinder(R)]

Orange essential oil was emulsified with water in the presence of various food additives (xanthan gum [11138-66-2], sorbitan monolaurate [1338-39-2], sorbitan monooleate [1338-43-8], ethoxylated sorbitan monooleate [9005-65-6], sucrose diacetate hexaisobutyrate [126-13-6], tragacanth gum [9000-65-1], and ester gum 8BG) and tested for light scattering quality, opacity, and stability, to det. the proper emulsifying agents for use in creating cloudy emulsions in soft drink manuf. Best results were obtained by using combinations of ester gums and the emulsifying agents. [on SciFinder(R)]

The optimal HLB for multiple emulsions was investigated and found dependent on the concns. of emulsifiers I and II. The shift of the optimal HLB at different emulsifier concns. is a result of the free emulsifier I which exists in the oil phase of the primary emulsion. A linear correlation between the optimal HLB, the concn. of emulsifier II, and the reciprocal concn. of emulsifier I is obsd. Yields of prepn. of the multiple emulsions were detd. by a chloride titrn. and cond. measurement, without using a dialysis cell. [on SciFinder(R)]

The release of electrolytes from multiple emulsions can be a result of the instability of the multiple droplets or diffusion through the oil-layer membrane. It was confirmed exptl. that, in the multiple system examd., the diffusion mechanism is the detg. factor in the release pattern of these electrolytes. The release is affected by the hydrophobicity of the electrolyte and by its concn., but not by the viscosity of the internal phase. Therefore, from a practical point of view it is not enough to obtain stable multiple emulsions; limiting and controlling the diffusion has also to be considered. [on SciFinder(R)]

Multiple (water-in-oil-in water) emulsions were prepd. by homogenizing 30 parts 1% NaCl with 70 parts of light mineral oil contg. varying amts. of Brij 92 emulsifier and then adding 20 parts of this primary emulsion to 80 parts of 5% glucose contg. varying amts. of mixts. of Span 20 [1338-39-2] and Tween 80 [9005-65-6] to provide hydrophile-lipophile balance (HLB) values of 9-15. At Tween-Span emulsifier mixt. concns. of 0.7-1.5% the yield of multiple emulsion was not affected by HLB value; droplet size detd. the yield. At emulsifier concns. \textgreater1.5% the yield decreased with increasing concn. at any HLB, related to a continuous decrease in multiple emulsion droplet size. Yields and emulsion stability were max. with an HLB value of 11 at emulsifier concns. \textgreater1.5%; at emulsifier mixt. concns. of 0.7-3% stability increased with increasing HLB value. Multiple emulsions are promising pharmaceutical forms. [on SciFinder(R)]

The exptl. conditions to maintain metastability in a soln. of Ca oxalate during 15 min were defined. Seed crystals of uric acid and Na urate were added, and the decrease in Ca ion concn. was measured by a Ca-selective electrode. Na urate crystals caused a decrease of ∼14%, while uric acid seeds were inactive. The growth of Ca oxalate on Na urate surface was confirmed by x-ray emission anal. When glutamic acid was added at 4-5 ppm concn. to the metastable soln. contg. uric acid seeds, a ∼28% Ca-concn. decrease was obsd. The pptn. of Ca oxalate on uric acid was confirmed by x-ray emission anal. A structural fit at an at. level between 2 solids, which is a necessary condition for epitaxy, is not sufficient for growth to occur. An addnl. factor, namely attraction at an ionic or mol. level, is also needed. It may be furnished by a mediating agent compatible with both solids. [on SciFinder(R)]